lifeline agm batteries

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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,746 ✭✭✭✭✭✭
    edited January 2017 #32
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    I used the Marine Surrette for 10 years and orrientation is not an issue as they are designed and built differently than land batteries.
    Gentlemen do not heel their boats anymore, they have catamarans :)
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • papab
    papab Registered Users Posts: 66 ✭✭
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    I don't want to go to an FLA since I'd have to deal with the venting.  I've decided to try to get another year or so out of this lifeline then try something different.  Perhaps lithium, the lead carbon also has potential.  firefly oasis, outback power.

    A basic trojan AGM looks like it would perform much better than this has.   In the IEC 61427 test they cycle between 10-40% SOC for 12.5 days, in addition to a higher SOC cycle, and got many of those in before failure.
    http://www.trojanbattery.com/pdf/27-AGM_IEC-61427.pdf
    I'm waiting to hear back from lifeline for there test results.


      
  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
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    Just a clarification about the floodies and bow-stern alignment being a no-no:  That is the alignment of the plates, and not the alignment of the case!  Just so nobody goes out and ruins an already good installation!

    Back to Lifeline and agm's in general - the EQ that a Lifeline can take, and the low-voltage limited time "freshening charge" for standard agm's is an *after the fact* corrective procedure that merely says you are not charging them fully often enough.  That last 1% takes a long time to charge,  but if it is not done regularly, it will walk your capacity down little by little, cycle by cycle.

    So instead of doing this corrective procedure, when using agm's one merely has to ensure that they are fully charged regularly.  Thus it behooves you with solar to run them at the higher end of the manufacturer's specs, and not baby them - since slight overcharge is less damaging than slight undercharge.  As mentioned before, this is never mentioned by manufacturers as they know consumers will misinterpret that as a green-light for total overcharge abuse, and will suffer a lot of warranty returns.  Essentially, slight positive plate corrosion will have less of a damaging effect than capacity reducing hard sulfation from undercharge.

    Essentially, if you have to do this with a Lifeline, then you need to fix your power-budget, and/or solar hardware to ensure a full charge so that you never have to do their EQ again!

    So with a little bit of knowledge, it is less of a matter of dancing on the head of a pin, but just knowing the difference between being slightly agressive and abuse, to ensure a full charge on a regular basis.


  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
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    AGM's and garbage:

    An additional note to the above - anybody having gassing problems and so forth with agm's when sticking to the high side of the manufacturer's ratings invariably end up with additional issues not mentioned up front but 30 messages later in the thread:

    1) Poorly balanced strings in the first place.  They just slam them in series, and wonder why they vent without doing a proper charge on each one individually before placing them into the series configuration.  Poor wiring infrastructure, different ages, models etc.

    2) Using garbage.  Usually a setup that consists of already used / abused batteries.  Very common is the desire to use trash agm's from used computer UPS systems.  Don't base your conclusions from trash.

  • papab
    papab Registered Users Posts: 66 ✭✭
    edited January 2017 #36
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    PNJ,  At least for the last 6-12 months,  I do try to charge at +.1 to +.4 over their spec.  I also use the finish charge feature in the trimetric solar charge controller which tries to hold a  constant current (2%) when the current drops below 2%, I have the max V set to 15.5 for the finish charge.   Ralph, the trimetric designer/owner said that he consulted with Lifeline for that.   Do you think this is OK?   I never let it sit at higher than recommended float V when it's charged up.  Of course, even in CO there are days of clouds.

    I've never heard any gassing and don't feel any expansion in the case.  
  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,144 ✭✭✭✭
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    papab said:
    I don't want to go to an FLA since I'd have to deal with the venting.  I've decided to try to get another year or so out of this lifeline then try something different.  Perhaps lithium, the lead carbon also has potential.  firefly oasis, outback power.

    A basic trojan AGM looks like it would perform much better than this has.   In the IEC 61427 test they cycle between 10-40% SOC for 12.5 days, in addition to a higher SOC cycle, and got many of those in before failure.
    http://www.trojanbattery.com/pdf/27-AGM_IEC-61427.pdf
    I'm waiting to hear back from lifeline for there test results.


      

    Yep, those are the published test results from Trojan, estimates of lifespan are always interesting. But to actually buy a Trojan AGM and see what happens. Next, find someone who owns them and ask about the extra long life that they got. I'll bet that they will suddenly become available in the near future.

    Another AGM manufacturer's new Atlanta plant is spooling up and already building certain batteries, and Fullriver isn't far behind.

    Marc
    I always have more questions than answers. That's the nature of life.
  • softdown
    softdown Solar Expert Posts: 3,821 ✭✭✭✭
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    papab said:
    I don't want to go to an FLA since I'd have to deal with the venting.  I've decided to try to get another year or so out of this lifeline then try something different.  Perhaps lithium, the lead carbon also has potential.  firefly oasis, outback power.

    A basic trojan AGM looks like it would perform much better than this has.   In the IEC 61427 test they cycle between 10-40% SOC for 12.5 days, in addition to a higher SOC cycle, and got many of those in before failure.
    http://www.trojanbattery.com/pdf/27-AGM_IEC-61427.pdf
    I'm waiting to hear back from lifeline for there test results.


      

    Yep, those are the published test results from Trojan, estimates of lifespan are always interesting. But to actually buy a Trojan AGM and see what happens. Next, find someone who owns them and ask about the extra long life that they got. I'll bet that they will suddenly become available in the near future.

    Another AGM manufacturer's new Atlanta plant is spooling up and already building certain batteries, and Fullriver isn't far behind.

    Marc
    Fullrivers been made in China. They going to make them here? That would....amaze me.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • wrcsixeight
    wrcsixeight Registered Users Posts: 4
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    PapaB,

    How often do/Did you employ the 60 amp Xantrax charging source?

    Even if 190 watts might be enought to return 110% to the Lifeline GPL-30HT in your usage, it cannot do it at lifeline's 20% minimum 'recommended' rate, which would be 30 amps for the lifeline GPL-30HT. They say this is most important when cycled to 50% or below and without it then one can extend the Absorption time  with a constant current of 0.02% for an hour, but does it really work in place of the minimum 20% rate?  I'd say your results lean toward no.

    I've been doing the campervan thing for many many years and gone through many sets of batteries while learning.  I once had 345Ah total, and now am down to just  90AH.  Why?  Because 200 watts of solar does not make  230AH, and certainly not 345AH of flooded 12v Marine battery happy.  When I went to 130 AH for the house bank(USbattery group31), I got the best bang for the buck, but high absorption voltages (14.9v)and a 15.3v finishing charge was required each day, and an EQ  at 16v for 45 minutes every 15 deep cycles, when using 35 to 65AH each night, were required to get that lifespan.  Lots of time and effort was required to get those ~500 deep cycles to an estimated average depth of about 55%, at least 6 nights a week.

    That 130Ah battery achieved ~500 cycles before I removed it from campervan.  I was going to make room for the trojan t-1275 in my engine compartment, and during that time I used my group 27 Northstar AGM as both house and engine battery.  When i took 65Ah from it, it still easily started my engine, and I questioned the need for a dedicated house battery. That was in June of 2015, and  It is still my ONLY battery.

    The trick to this AGM, in my experience,  is the high amp recharge from its most depleted state.  I use a 40 amp Meanwell power supply, RSP-500-15, when I can plug in.  I have  modified it with more heatsinking , fans, and an external voltage potentiometer with an upgraded (8awg) wattmeter on DC output.

    My Solar is 198 watts, kyocera 130GT Installed in  2007 and a Unisolar PVL-68(2012), into a bluesky sb2512i and IPN proremote to adjust Vabs and float.

    I also utilize the alternator, and think it is insane to not utlilize this massive bulk charging source.  My Van's voltage regulator was the weak point, choosing wither 13.7v or 14.9v with no regards to logic. But when 14.9v was chosen, and the battery was depleted, and I was moving with an engine rpm above 1800, well l have seen as high as 106 amps into Northstar when it was newer.

    About a year ago, I  tricked my engine computer's voltage regulator with a 10 OHM 50 watt resistor inline, and  now use an external Transpo540HD voltage regulator.  This VR has a potentiometer inside to change voltage. I snipped the legs off, soldered wires to the legs, run it to a 10 turn Bourns potentiometer  located on my dashboard next to my voltmeters, and choose the voltage I want the battery to get whenever I drive.  I have added a heatsink and 60Mm computer fan to the  backside of the transpo540HD 

    I also have a Hall efffect ammeter on the Alternators (+) output whose display is visible next to voltage potentiometer, but will at some point move the sensor to a battery cable to see amps into or out of abttery instead of total alterantor amperage.

    I bought this Northstar AGM in November of 2013.  It now has ~ 450 Deep cycles on it, many of them down to 65 or 70Ah from full.  it has several hundred more shallow cycles to 85-90%, and several thousand engine starts on it.

    Right now my battery monitor, recently rezeroed is displaying 33Ah from full and 59% charged.  Battery temperature is 62 degreesf and holding 12.29v under a 3.9 amp load.It has been depleted this far in 6 hours, which would be an ~5.5 amp average  discharge rate, when it achieved a 90Ah capacity rating at 4.5 amps.  It has actually been quite a while since I fed it 40+ amps from this level of depletion, but this has always been the ticket to restoring performance so I am finding these numbers pleasing.

    High amps from the most depleted state.  if I wait until 9 or 10 AM before driving or plugging in, then the solar has refilled it slowly to some degree, and  it either cannot accept 40 amps, or cant accept it for long, and the performance reset does not occur.

    However if I start the engine and get on the highway before sunrise  and dial it upto 14.7v quickly at upto 106 amps, get it to 80% quickly, then let the solar take over and finish the task, performance seems to return to nearly that of when it was new. i judge performance by voltage held  for AH removed in normal discharging under load overnight, and voltage maintained when cranking engine next morning.

    I too have noticed the time it takes amps to taper to below 0.45 at 14.7v to be taking longer than when new. This time also  gets longer and longer without the high amp recharge from the most depleted state, and is especially noticeable in winter.

    I could not keep this battery happy with solar alone, not at 50% discharges, but I have 40 amps plug in and upto ~105 amps available from alternator.  It is a 120 amp alternator but the engine alone requires 12.2 amps at 2000 rpm.

    I would suggest depleting your Lifeline to 50% or Below setting the 60 amps or more loose on it, up Absorption voltage to 14.6, perhaps higher, and hold it, and then see if the tapering to 0.5% of capacity takes less time.

    I suspect allowing a tapering to 1% of capacity as a termination point  on an aged battery, would not be recommended by lifeline.

    Try the High amp recharge.  The GPL-30ht  at 150Ah capacity will laugh at 60 amps.

    My Northstar group 27 at 90AH   depleted below 50%  at 350 cycles could  take 65 amps for nearly a half hour before tapering begins from 14.7v..  Will check again at 450 cycles, perhaps tonight.

    Granted it is a thin plate pure lead dual purpose AGM battery, not a dedicated deep cycle AGM design, but I do not think you can do better than a Lifeline in a Deep cycle application when an AGM is required.

    I had  a lifeline GPL-31XT for a powerpack project for a friend, and Was impressed with it, and according to him it still works well.  Its two chrging sources are 160 amp of alternator fed by 2awg cable, at mercy of vehicles voltage regulator of course, and a Progressive dynamics PD9245.

    High Amp recharge.  Perhaps not every time, but the more often the better for these AGM's in my opinion and Limited experience.  i do not feel the Extended absorption or a constant current of 0.02% of capacity after normal absorption will do the same thing as getting that electorlyte a Migrating and heating when fed at a high rate for a good while from the  most depleted State.

    I am also hoping to hear more about the performance in use of the Firefly carbon foam AGM's, and if they prove to be as tolerannt of PSOC use as they claim, Well I'd throw down for it, but honestly i'd also get another Northstar unless it falls flat tomorrow, but all signs say it is still healthy so that possibility seems remote.

    What I love about these high$$ AGMS is the abilityu to take HUGE charging currents. The Flooded could accept them but did not appreciate them.  Get them to 80% quickly at a high rate then solar can finish the job.  I do not think they will be happy when deeply cycled and low and slow solar is the only, or primary charging source.

    Hook up that alternator with thick cable, and do not idle to recharge, drive. I have alternator temp data.  Even at 90 amps continuous at 65 MPH it will not exceed 134f. but slow down and maxed out the numbers climb quickly to 200F.  Idling hot maxed out is even worse, and I can only get 42 amps total and 8.2 of those are running the engine.
  • papab
    papab Registered Users Posts: 66 ✭✭
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    How often do I use the xantrex?   Lately quite a bit since I can plug into my house under construction now.   Prior to a month ago, usually for a short time (<1 hr) every day or 2 when driving.   The SOC is usually not low enough take 60 amps though.   I've only been below 70% once in the last year (other than the discharge tests), and usually above 80%.   Makes a good case for a smaller battery doesn't it.    You may have a good point about the lifeline needing high amps to be happy, but I asked the lifeline rep about my low discharge cycles and he didn't think that was a problem, but it was actually really good.

    I can charge directly from the big van alternator too, but I haven't had the the battery low enough for that for over a year.  

    I noticed that when I did the recharge after the discharge test that it did get to .5%C rate fairly quickly, but then the next day with a smaller DOD it was back to being slow again.  

  • softdown
    softdown Solar Expert Posts: 3,821 ✭✭✭✭
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    PapaB,

    How often do/Did you employ the 60 amp Xantrax charging source?

    Even if 190 watts might be enought to return 110% to the Lifeline GPL-30HT in your usage, it cannot do it at lifeline's 20% minimum 'recommended' rate, which would be 30 amps for the lifeline GPL-30HT. They say this is most important when cycled to 50% or below and without it then one can extend the Absorption time  with a constant current of 0.02% for an hour, but does it really work in place of the minimum 20% rate?  I'd say your results lean toward no.

    I've been doing the campervan thing for many many years and gone through many sets of batteries while learning.  I once had 345Ah total, and now am down to just  90AH.  Why?  Because 200 watts of solar does not make  230AH, and certainly not 345AH of flooded 12v Marine battery happy.  When I went to 130 AH for the house bank(USbattery group31), I got the best bang for the buck, but high absorption voltages (14.9v)and a 15.3v finishing charge was required each day, and an EQ  at 16v for 45 minutes every 15 deep cycles, when using 35 to 65AH each night, were required to get that lifespan.  Lots of time and effort was required to get those ~500 deep cycles to an estimated average depth of about 55%, at least 6 nights a week.

    That 130Ah battery achieved ~500 cycles before I removed it from campervan.  I was going to make room for the trojan t-1275 in my engine compartment, and during that time I used my group 27 Northstar AGM as both house and engine battery.  When i took 65Ah from it, it still easily started my engine, and I questioned the need for a dedicated house battery. That was in June of 2015, and  It is still my ONLY battery.

    The trick to this AGM, in my experience,  is the high amp recharge from its most depleted state.  I use a 40 amp Meanwell power supply, RSP-500-15, when I can plug in.  I have  modified it with more heatsinking , fans, and an external voltage potentiometer with an upgraded (8awg) wattmeter on DC output.

    My Solar is 198 watts, kyocera 130GT Installed in  2007 and a Unisolar PVL-68(2012), into a bluesky sb2512i and IPN proremote to adjust Vabs and float.

    I also utilize the alternator, and think it is insane to not utlilize this massive bulk charging source.  My Van's voltage regulator was the weak point, choosing wither 13.7v or 14.9v with no regards to logic. But when 14.9v was chosen, and the battery was depleted, and I was moving with an engine rpm above 1800, well l have seen as high as 106 amps into Northstar when it was newer.

    About a year ago, I  tricked my engine computer's voltage regulator with a 10 OHM 50 watt resistor inline, and  now use an external Transpo540HD voltage regulator.  This VR has a potentiometer inside to change voltage. I snipped the legs off, soldered wires to the legs, run it to a 10 turn Bourns potentiometer  located on my dashboard next to my voltmeters, and choose the voltage I want the battery to get whenever I drive.  I have added a heatsink and 60Mm computer fan to the  backside of the transpo540HD 

    I also have a Hall efffect ammeter on the Alternators (+) output whose display is visible next to voltage potentiometer, but will at some point move the sensor to a battery cable to see amps into or out of abttery instead of total alterantor amperage.

    I bought this Northstar AGM in November of 2013.  It now has ~ 450 Deep cycles on it, many of them down to 65 or 70Ah from full.  it has several hundred more shallow cycles to 85-90%, and several thousand engine starts on it.

    Right now my battery monitor, recently rezeroed is displaying 33Ah from full and 59% charged.  Battery temperature is 62 degreesf and holding 12.29v under a 3.9 amp load.It has been depleted this far in 6 hours, which would be an ~5.5 amp average  discharge rate, when it achieved a 90Ah capacity rating at 4.5 amps.  It has actually been quite a while since I fed it 40+ amps from this level of depletion, but this has always been the ticket to restoring performance so I am finding these numbers pleasing.

    High amps from the most depleted state.  if I wait until 9 or 10 AM before driving or plugging in, then the solar has refilled it slowly to some degree, and  it either cannot accept 40 amps, or cant accept it for long, and the performance reset does not occur.

    However if I start the engine and get on the highway before sunrise  and dial it upto 14.7v quickly at upto 106 amps, get it to 80% quickly, then let the solar take over and finish the task, performance seems to return to nearly that of when it was new. i judge performance by voltage held  for AH removed in normal discharging under load overnight, and voltage maintained when cranking engine next morning.

    I too have noticed the time it takes amps to taper to below 0.45 at 14.7v to be taking longer than when new. This time also  gets longer and longer without the high amp recharge from the most depleted state, and is especially noticeable in winter.

    I could not keep this battery happy with solar alone, not at 50% discharges, but I have 40 amps plug in and upto ~105 amps available from alternator.  It is a 120 amp alternator but the engine alone requires 12.2 amps at 2000 rpm.

    I would suggest depleting your Lifeline to 50% or Below setting the 60 amps or more loose on it, up Absorption voltage to 14.6, perhaps higher, and hold it, and then see if the tapering to 0.5% of capacity takes less time.

    I suspect allowing a tapering to 1% of capacity as a termination point  on an aged battery, would not be recommended by lifeline.

    Try the High amp recharge.  The GPL-30ht  at 150Ah capacity will laugh at 60 amps.

    My Northstar group 27 at 90AH   depleted below 50%  at 350 cycles could  take 65 amps for nearly a half hour before tapering begins from 14.7v..  Will check again at 450 cycles, perhaps tonight.

    Granted it is a thin plate pure lead dual purpose AGM battery, not a dedicated deep cycle AGM design, but I do not think you can do better than a Lifeline in a Deep cycle application when an AGM is required.

    I had  a lifeline GPL-31XT for a powerpack project for a friend, and Was impressed with it, and according to him it still works well.  Its two chrging sources are 160 amp of alternator fed by 2awg cable, at mercy of vehicles voltage regulator of course, and a Progressive dynamics PD9245.

    High Amp recharge.  Perhaps not every time, but the more often the better for these AGM's in my opinion and Limited experience.  i do not feel the Extended absorption or a constant current of 0.02% of capacity after normal absorption will do the same thing as getting that electorlyte a Migrating and heating when fed at a high rate for a good while from the  most depleted State.

    I am also hoping to hear more about the performance in use of the Firefly carbon foam AGM's, and if they prove to be as tolerannt of PSOC use as they claim, Well I'd throw down for it, but honestly i'd also get another Northstar unless it falls flat tomorrow, but all signs say it is still healthy so that possibility seems remote.

    What I love about these high$$ AGMS is the abilityu to take HUGE charging currents. The Flooded could accept them but did not appreciate them.  Get them to 80% quickly at a high rate then solar can finish the job.  I do not think they will be happy when deeply cycled and low and slow solar is the only, or primary charging source.

    Hook up that alternator with thick cable, and do not idle to recharge, drive. I have alternator temp data.  Even at 90 amps continuous at 65 MPH it will not exceed 134f. but slow down and maxed out the numbers climb quickly to 200F.  Idling hot maxed out is even worse, and I can only get 42 amps total and 8.2 of those are running the engine.
    That is amazing for a thin plate battery. Right now I am thinking that pure lead must be 100% better than lead-calcium. As is often the case, price indicates quality.

    Perhaps it is simply difficult to refine the calcium out of lead? That the calcium somehow acts as resistance and dead spots..?

    You are getting better performance out of a thin plate than most do out of their thick plate. Thin plates usually enjoy very short lives.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    I believe that calcium was added to reduce water usage and make the battery "maintenance free".

    https://en.wikipedia.org/wiki/Lead–acid_battery
    High-antimony alloy grids are still used in batteries intended for frequent cycling, e.g. in motor-starting applications where frequent expansion/contraction of the plates needs to be compensated for, but where outgassing is not significant since charge currents remain low. Since the 1950s, batteries designed for infrequent cycling applications (e.g., standby power batteries) increasingly have lead-calcium or lead-selenium alloy grids since these have less hydrogen evolution and thus lower maintenance overhead. Lead-calcium alloy grids are cheaper to manufacture (the cells thus have lower up-front costs), and have a lower self-discharge rate, and lower watering requirements, but have slightly poorer conductivity, are mechanically weaker (and thus require more antimony to compensate), and are strongly subject to corrosion (and thus a shorter lifespan) than cells with lead-selenium alloy grids.
    And "cheaper too"... Of course.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
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    @wrcsixeight - I'm also thinking of doing the solo battery thing on my boat. Maybe one big 12v AGM in a size that will fit in the box where a 12v starting and two 6v GCs live now. Do you have one of those lithium emergency boosters to start in case Murphy runs your single battery down too far to start?
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • wrcsixeight
    wrcsixeight Registered Users Posts: 4
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    I am impressed with the Northstar's performance.  "thin plate" and Deep cycle are at opposite ends, but somehow this battery is still performing well, however I do not have the ability to do a true 20 hour capacity test.  I've been checking voltage when I remove 45AH since it was new, and there is not much differnece, but I assume all the difference would be a steep dive after that point

    When new, its ability to crank my engine was downright scary fast.  It has lost  a lot of that 'scary fast' with age and ~450 deep cycles, but is by no means slow.

    Back when I had 3 group 27's, 2 for house one for engine, I was going through the 2 27's in about 2 years, but my absorption times were not long enough. I was still one of those who believed float =full.  Later, A hydrometer proved me so wrong and I felt like a huge fool for not using one earlier..

    I did have the theory that my 198 watts of solar was just too little current for that much capacity, even if I could achieve float by 1PM, so when the last set of 27's failed I went with a single flooded group 31 and bought the Northstar-27 at the same time, but after 4 weeks I was not impressed with overnight voltages on the 31, and the hydrometer revealed 1.225 when it went into float.

    The difficulty of accessing the cells  on the 31, had me swap battery locations, and each day I adjusted my Absorption voltage and duration higher until it was able to get near 1.280 via solar, and mostly solar alone.

    The alternator  and 4 gauge cable threw a money wrench in that hunt, but the days i did not drive, showed that 14.9vABS and a 15.3v finish proved to be the only way i could get to 1.275+ each day via solar alone.  I simply set my float to 15.3v, and after 2 weeks i would have to switch all loads to the Northstar via a Switch, bump vABS to 16, and give it about 45 minutes for all cells to get back upto 1.280, and amps taper from 6.5 to 4.2.  Later on I just used 4.2 amps as a threshold for ending EQ without dipping hydrometer.

    One day i noticed it at 4.6 amps at 16v, came back ~15 minutes later and saw it a 5.4 amps at 16V, and my IR thermometer revealed that the bottom of one cell closest to (-) battery terminal was 15 degrees hotter than the rest of the battery and i removed it from the van, and started cycling the Northstar.  The hot cell refused to get above 1.265 and had been showing reluctance to respond to EQ charges for a month or 2 previous.

    Surprisingly that battery, now being cycled very lightly, is still going powering LED lights and computer fans in my workshop, and that cell has not shorted and I do not ever see its temperature climb when recharging at 12 or even 25 amps.  Specific gravity has also risen on the weak cell last I checked it.

    Anyway, The TPPL AGM battery has proved to be quite impressive in my uses, and I do use the Dual purpose aspect of it, having it start me engine as well.  I am carrying around ~120 Lbs less lead and have more confidence in my system than when I had 345AH  total capacity.

    But that confidence comes from better ability to recharge.  i am limited to 198 watts as I cannot fit more on my roof, but the alternator via thick cabling and an adjustable voltage regulator allow me to dump huge amperages into it, and my Adjustable voltage power supply  allow me 40 amps and ability to hold absorption voltage until amps taper to 0.5% of capacity or less each time I plug in.

    None of that false green light or float = full  mindset is what i credit the Northstar's good performance to.  That and the ability to hammer it with high amperages when most depleted.

    When it was new,  I did not have the Adjustable voltage Meanwell power supply Or the adjustable alternator voltage regulator, but I also did not frequently deeply cycle it either, perhaps once every 30 days.

    I know the 'Slow recharge to full' is almost always touted as ideal everywhere online, with the exception of Odyssey's 40% minimum initial current, but I feel that a battery can easily accept higher amperages, even the flooded versions, and that this low and slow is always best might sound good on paper and in theory, but in practice, does not add up.  At least not in a mobile application.

    My flooded group31 was exposed to not only engine heat, but the same alternator amperages, and still was able to achieve 500 deep cycles when massaged with high Vabs and finishing voltages and regular EQ charges.

    I think much of the low and slow  recommended protocols are too timid and that higher amperages when most depleted is actually beneficial.   My Opinion, obviously.


    One other thing I can add, is that my Northstar-27 when new, I could not get the resting fully charged voltage upto 13.0+ as per Northstar's data sheet, until I did a deep cycle and a high amp recharge.  After that, its full charge resting voltage was 13.06v, at least until I put it into full dual purpose duty, and now it never gets any rest so I do not know what its fully charged resting voltage is now. 

    i do wonder how much life i could get out of flooded marine batteries now with my ability to recharge as good as possible, but I am pretty much an AGM convert and would have no issues buying another Northstar or an Odyssey TPPL for my uses.

    I am considering buying a small Odyssey just to have as a emergency jump starter for when the Northstar becomes too weak to start the engine when depleted to 50%.


  • softdown
    softdown Solar Expert Posts: 3,821 ✭✭✭✭
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    BB. said:
    I believe that calcium was added to reduce water usage and make the battery "maintenance free".

    https://en.wikipedia.org/wiki/Lead–acid_battery
    High-antimony alloy grids are still used in batteries intended for frequent cycling, e.g. in motor-starting applications where frequent expansion/contraction of the plates needs to be compensated for, but where outgassing is not significant since charge currents remain low. Since the 1950s, batteries designed for infrequent cycling applications (e.g., standby power batteries) increasingly have lead-calcium or lead-selenium alloy grids since these have less hydrogen evolution and thus lower maintenance overhead. Lead-calcium alloy grids are cheaper to manufacture (the cells thus have lower up-front costs), and have a lower self-discharge rate, and lower watering requirements, but have slightly poorer conductivity, are mechanically weaker (and thus require more antimony to compensate), and are strongly subject to corrosion (and thus a shorter lifespan) than cells with lead-selenium alloy grids.
    And "cheaper too"... Of course.

    -Bill
    Cheaper:
    Less water usage
    Lower self-discharge rate
    Lower conductivity (could be a huge factor)
    Mechanically weaker (could be huge if many bad cells are caused by loss of bus bar)
    Strongly subject to corrosion and shorter lifespan (is this code for sulfation)

    Well.....for solar....looks like pure lead or lead-selenium is worth it. Perhaps we have discovered a few reasons for the longevity of forklift batteries.

    If only we had accurate rating for percentages of calcium and selenium. That would likely tell us a lot. Calcium is really, really cheap.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
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    softdown said:
    PapaB,

    How often do/Did you employ the 60 amp Xantrax charging source?

    Even if 190 watts might be enought to return 110% to the Lifeline GPL-30HT in your usage, it cannot do it at lifeline's 20% minimum 'recommended' rate, which would be 30 amps for the lifeline GPL-30HT. They say this is most important when cycled to 50% or below and without it then one can extend the Absorption time  with a constant current of 0.02% for an hour, but does it really work in place of the minimum 20% rate?  I'd say your results lean toward no.

    I've been doing the campervan thing for many many years and gone through many sets of batteries while learning.  I once had 345Ah total, and now am down to just  90AH.  Why?  Because 200 watts of solar does not make  230AH, and certainly not 345AH of flooded 12v Marine battery happy.  When I went to 130 AH for the house bank(USbattery group31), I got the best bang for the buck, but high absorption voltages (14.9v)and a 15.3v finishing charge was required each day, and an EQ  at 16v for 45 minutes every 15 deep cycles, when using 35 to 65AH each night, were required to get that lifespan.  Lots of time and effort was required to get those ~500 deep cycles to an estimated average depth of about 55%, at least 6 nights a week.

    That 130Ah battery achieved ~500 cycles before I removed it from campervan.  I was going to make room for the trojan t-1275 in my engine compartment, and during that time I used my group 27 Northstar AGM as both house and engine battery.  When i took 65Ah from it, it still easily started my engine, and I questioned the need for a dedicated house battery. That was in June of 2015, and  It is still my ONLY battery.

    The trick to this AGM, in my experience,  is the high amp recharge from its most depleted state.  I use a 40 amp Meanwell power supply, RSP-500-15, when I can plug in.  I have  modified it with more heatsinking , fans, and an external voltage potentiometer with an upgraded (8awg) wattmeter on DC output.

    My Solar is 198 watts, kyocera 130GT Installed in  2007 and a Unisolar PVL-68(2012), into a bluesky sb2512i and IPN proremote to adjust Vabs and float.

    I also utilize the alternator, and think it is insane to not utlilize this massive bulk charging source.  My Van's voltage regulator was the weak point, choosing wither 13.7v or 14.9v with no regards to logic. But when 14.9v was chosen, and the battery was depleted, and I was moving with an engine rpm above 1800, well l have seen as high as 106 amps into Northstar when it was newer.

    About a year ago, I  tricked my engine computer's voltage regulator with a 10 OHM 50 watt resistor inline, and  now use an external Transpo540HD voltage regulator.  This VR has a potentiometer inside to change voltage. I snipped the legs off, soldered wires to the legs, run it to a 10 turn Bourns potentiometer  located on my dashboard next to my voltmeters, and choose the voltage I want the battery to get whenever I drive.  I have added a heatsink and 60Mm computer fan to the  backside of the transpo540HD 

    I also have a Hall efffect ammeter on the Alternators (+) output whose display is visible next to voltage potentiometer, but will at some point move the sensor to a battery cable to see amps into or out of abttery instead of total alterantor amperage.

    I bought this Northstar AGM in November of 2013.  It now has ~ 450 Deep cycles on it, many of them down to 65 or 70Ah from full.  it has several hundred more shallow cycles to 85-90%, and several thousand engine starts on it.

    Right now my battery monitor, recently rezeroed is displaying 33Ah from full and 59% charged.  Battery temperature is 62 degreesf and holding 12.29v under a 3.9 amp load.It has been depleted this far in 6 hours, which would be an ~5.5 amp average  discharge rate, when it achieved a 90Ah capacity rating at 4.5 amps.  It has actually been quite a while since I fed it 40+ amps from this level of depletion, but this has always been the ticket to restoring performance so I am finding these numbers pleasing.

    High amps from the most depleted state.  if I wait until 9 or 10 AM before driving or plugging in, then the solar has refilled it slowly to some degree, and  it either cannot accept 40 amps, or cant accept it for long, and the performance reset does not occur.

    However if I start the engine and get on the highway before sunrise  and dial it upto 14.7v quickly at upto 106 amps, get it to 80% quickly, then let the solar take over and finish the task, performance seems to return to nearly that of when it was new. i judge performance by voltage held  for AH removed in normal discharging under load overnight, and voltage maintained when cranking engine next morning.

    I too have noticed the time it takes amps to taper to below 0.45 at 14.7v to be taking longer than when new. This time also  gets longer and longer without the high amp recharge from the most depleted state, and is especially noticeable in winter.

    I could not keep this battery happy with solar alone, not at 50% discharges, but I have 40 amps plug in and upto ~105 amps available from alternator.  It is a 120 amp alternator but the engine alone requires 12.2 amps at 2000 rpm.

    I would suggest depleting your Lifeline to 50% or Below setting the 60 amps or more loose on it, up Absorption voltage to 14.6, perhaps higher, and hold it, and then see if the tapering to 0.5% of capacity takes less time.

    I suspect allowing a tapering to 1% of capacity as a termination point  on an aged battery, would not be recommended by lifeline.

    Try the High amp recharge.  The GPL-30ht  at 150Ah capacity will laugh at 60 amps.

    My Northstar group 27 at 90AH   depleted below 50%  at 350 cycles could  take 65 amps for nearly a half hour before tapering begins from 14.7v..  Will check again at 450 cycles, perhaps tonight.

    Granted it is a thin plate pure lead dual purpose AGM battery, not a dedicated deep cycle AGM design, but I do not think you can do better than a Lifeline in a Deep cycle application when an AGM is required.

    I had  a lifeline GPL-31XT for a powerpack project for a friend, and Was impressed with it, and according to him it still works well.  Its two chrging sources are 160 amp of alternator fed by 2awg cable, at mercy of vehicles voltage regulator of course, and a Progressive dynamics PD9245.

    High Amp recharge.  Perhaps not every time, but the more often the better for these AGM's in my opinion and Limited experience.  i do not feel the Extended absorption or a constant current of 0.02% of capacity after normal absorption will do the same thing as getting that electorlyte a Migrating and heating when fed at a high rate for a good while from the  most depleted State.

    I am also hoping to hear more about the performance in use of the Firefly carbon foam AGM's, and if they prove to be as tolerannt of PSOC use as they claim, Well I'd throw down for it, but honestly i'd also get another Northstar unless it falls flat tomorrow, but all signs say it is still healthy so that possibility seems remote.

    What I love about these high$$ AGMS is the abilityu to take HUGE charging currents. The Flooded could accept them but did not appreciate them.  Get them to 80% quickly at a high rate then solar can finish the job.  I do not think they will be happy when deeply cycled and low and slow solar is the only, or primary charging source.

    Hook up that alternator with thick cable, and do not idle to recharge, drive. I have alternator temp data.  Even at 90 amps continuous at 65 MPH it will not exceed 134f. but slow down and maxed out the numbers climb quickly to 200F.  Idling hot maxed out is even worse, and I can only get 42 amps total and 8.2 of those are running the engine.
    That is amazing for a thin plate battery. Right now I am thinking that pure lead must be 100% better than lead-calcium. As is often the case, price indicates quality.

    Perhaps it is simply difficult to refine the calcium out of lead? That the calcium somehow acts as resistance and dead spots..?

    You are getting better performance out of a thin plate than most do out of their thick plate. Thin plates usually enjoy very short lives.


    This Discussion revolves around AGM batteries.   All of the AGM batteries that I've seen,  are Lead-Calcium,  because the Calcium added to the Lead reduces Gassing (it is Gassing that causes water consumption).  The Calcium was designed into the battery.

    IMO,   Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • softdown
    softdown Solar Expert Posts: 3,821 ✭✭✭✭
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    Vic said:
    softdown said:
    PapaB,

    How often do/Did you employ the 60 amp Xantrax charging source?

    Even if 190 watts might be enought to return 110% to the Lifeline GPL-30HT in your usage, it cannot do it at lifeline's 20% minimum 'recommended' rate, which would be 30 amps for the lifeline GPL-30HT. They say this is most important when cycled to 50% or below and without it then one can extend the Absorption time  with a constant current of 0.02% for an hour, but does it really work in place of the minimum 20% rate?  I'd say your results lean toward no.

    I've been doing the campervan thing for many many years and gone through many sets of batteries while learning.  I once had 345Ah total, and now am down to just  90AH.  Why?  Because 200 watts of solar does not make  230AH, and certainly not 345AH of flooded 12v Marine battery happy.  When I went to 130 AH for the house bank(USbattery group31), I got the best bang for the buck, but high absorption voltages (14.9v)and a 15.3v finishing charge was required each day, and an EQ  at 16v for 45 minutes every 15 deep cycles, when using 35 to 65AH each night, were required to get that lifespan.  Lots of time and effort was required to get those ~500 deep cycles to an estimated average depth of about 55%, at least 6 nights a week.

    That 130Ah battery achieved ~500 cycles before I removed it from campervan.  I was going to make room for the trojan t-1275 in my engine compartment, and during that time I used my group 27 Northstar AGM as both house and engine battery.  When i took 65Ah from it, it still easily started my engine, and I questioned the need for a dedicated house battery. That was in June of 2015, and  It is still my ONLY battery.

    The trick to this AGM, in my experience,  is the high amp recharge from its most depleted state.  I use a 40 amp Meanwell power supply, RSP-500-15, when I can plug in.  I have  modified it with more heatsinking , fans, and an external voltage potentiometer with an upgraded (8awg) wattmeter on DC output.

    My Solar is 198 watts, kyocera 130GT Installed in  2007 and a Unisolar PVL-68(2012), into a bluesky sb2512i and IPN proremote to adjust Vabs and float.

    I also utilize the alternator, and think it is insane to not utlilize this massive bulk charging source.  My Van's voltage regulator was the weak point, choosing wither 13.7v or 14.9v with no regards to logic. But when 14.9v was chosen, and the battery was depleted, and I was moving with an engine rpm above 1800, well l have seen as high as 106 amps into Northstar when it was newer.

    About a year ago, I  tricked my engine computer's voltage regulator with a 10 OHM 50 watt resistor inline, and  now use an external Transpo540HD voltage regulator.  This VR has a potentiometer inside to change voltage. I snipped the legs off, soldered wires to the legs, run it to a 10 turn Bourns potentiometer  located on my dashboard next to my voltmeters, and choose the voltage I want the battery to get whenever I drive.  I have added a heatsink and 60Mm computer fan to the  backside of the transpo540HD 

    I also have a Hall efffect ammeter on the Alternators (+) output whose display is visible next to voltage potentiometer, but will at some point move the sensor to a battery cable to see amps into or out of abttery instead of total alterantor amperage.

    I bought this Northstar AGM in November of 2013.  It now has ~ 450 Deep cycles on it, many of them down to 65 or 70Ah from full.  it has several hundred more shallow cycles to 85-90%, and several thousand engine starts on it.

    Right now my battery monitor, recently rezeroed is displaying 33Ah from full and 59% charged.  Battery temperature is 62 degreesf and holding 12.29v under a 3.9 amp load.It has been depleted this far in 6 hours, which would be an ~5.5 amp average  discharge rate, when it achieved a 90Ah capacity rating at 4.5 amps.  It has actually been quite a while since I fed it 40+ amps from this level of depletion, but this has always been the ticket to restoring performance so I am finding these numbers pleasing.

    High amps from the most depleted state.  if I wait until 9 or 10 AM before driving or plugging in, then the solar has refilled it slowly to some degree, and  it either cannot accept 40 amps, or cant accept it for long, and the performance reset does not occur.

    However if I start the engine and get on the highway before sunrise  and dial it upto 14.7v quickly at upto 106 amps, get it to 80% quickly, then let the solar take over and finish the task, performance seems to return to nearly that of when it was new. i judge performance by voltage held  for AH removed in normal discharging under load overnight, and voltage maintained when cranking engine next morning.

    I too have noticed the time it takes amps to taper to below 0.45 at 14.7v to be taking longer than when new. This time also  gets longer and longer without the high amp recharge from the most depleted state, and is especially noticeable in winter.

    I could not keep this battery happy with solar alone, not at 50% discharges, but I have 40 amps plug in and upto ~105 amps available from alternator.  It is a 120 amp alternator but the engine alone requires 12.2 amps at 2000 rpm.

    I would suggest depleting your Lifeline to 50% or Below setting the 60 amps or more loose on it, up Absorption voltage to 14.6, perhaps higher, and hold it, and then see if the tapering to 0.5% of capacity takes less time.

    I suspect allowing a tapering to 1% of capacity as a termination point  on an aged battery, would not be recommended by lifeline.

    Try the High amp recharge.  The GPL-30ht  at 150Ah capacity will laugh at 60 amps.

    My Northstar group 27 at 90AH   depleted below 50%  at 350 cycles could  take 65 amps for nearly a half hour before tapering begins from 14.7v..  Will check again at 450 cycles, perhaps tonight.

    Granted it is a thin plate pure lead dual purpose AGM battery, not a dedicated deep cycle AGM design, but I do not think you can do better than a Lifeline in a Deep cycle application when an AGM is required.

    I had  a lifeline GPL-31XT for a powerpack project for a friend, and Was impressed with it, and according to him it still works well.  Its two chrging sources are 160 amp of alternator fed by 2awg cable, at mercy of vehicles voltage regulator of course, and a Progressive dynamics PD9245.

    High Amp recharge.  Perhaps not every time, but the more often the better for these AGM's in my opinion and Limited experience.  i do not feel the Extended absorption or a constant current of 0.02% of capacity after normal absorption will do the same thing as getting that electorlyte a Migrating and heating when fed at a high rate for a good while from the  most depleted State.

    I am also hoping to hear more about the performance in use of the Firefly carbon foam AGM's, and if they prove to be as tolerannt of PSOC use as they claim, Well I'd throw down for it, but honestly i'd also get another Northstar unless it falls flat tomorrow, but all signs say it is still healthy so that possibility seems remote.

    What I love about these high$$ AGMS is the abilityu to take HUGE charging currents. The Flooded could accept them but did not appreciate them.  Get them to 80% quickly at a high rate then solar can finish the job.  I do not think they will be happy when deeply cycled and low and slow solar is the only, or primary charging source.

    Hook up that alternator with thick cable, and do not idle to recharge, drive. I have alternator temp data.  Even at 90 amps continuous at 65 MPH it will not exceed 134f. but slow down and maxed out the numbers climb quickly to 200F.  Idling hot maxed out is even worse, and I can only get 42 amps total and 8.2 of those are running the engine.
    That is amazing for a thin plate battery. Right now I am thinking that pure lead must be 100% better than lead-calcium. As is often the case, price indicates quality.

    Perhaps it is simply difficult to refine the calcium out of lead? That the calcium somehow acts as resistance and dead spots..?

    You are getting better performance out of a thin plate than most do out of their thick plate. Thin plates usually enjoy very short lives.


    This Discussion revolves around AGM batteries.   All of the AGM batteries that I've seen,  are Lead-Calcium,  because the Calcium added to the Lead reduces Gassing (it is Gassing that causes water consumption).  The Calcium was designed into the battery.

    IMO,   Vic

    Aren't you the assertive one. I believe the headline is specifically "lifeline-agm-batteries". wrcsixeight said this regarding the lifeline agm: "Granted it is a thin plate pure lead dual purpose AGM battery, not a dedicated deep cycle AGM design, but I do not think you can do better than a Lifeline in a Deep cycle application when an AGM is required."

    Spent some time on Lifelines web site. They talked about quality of construction rather than chemistry of materials used. It is unfortunate that marketing has to be so absolutely dumbed down to be effective.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdown
    softdown Solar Expert Posts: 3,821 ✭✭✭✭
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    For the record, I bought "pure lead" AGMs by Fullriver. Have not installed yet. So....pure lead AGMs exist. They are $$$.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
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    Hello soft..,

    You said,  "Aren't you the assertive one".   Yes,  indeed,  it is I.

    Often,  with batteries,  when a manufacturer sais  it has a "pure lead plate',  they are not necessarily saying that the plate is made ONLY of lead,  but rather,   that the lead in the plate is pure.

    Speaking of the Lifeline AGMs,  the Link to the Technical manual,  in Section 2.1    "Component Description" - GRIDS,  it is stated that the Negative Plate  is made of a pure lead calcium alloy,   and that the Positive plate is made of pure lead-tin-calcium alloy:

    http://lifelinebatteries.com/wp-content/uploads/2015/12/manual.pdf

    It may be just me,   but,  seems to be saying that the Lifeline AGM batteries ARE in the general class of a Lead-Calcium battery.

    Just my assertions,   Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • softdown
    softdown Solar Expert Posts: 3,821 ✭✭✭✭
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    Sounds like you did your homework, too distracted to dig in at the moment. I'm pretty sure that I have seen Fullriver advertising as "pure lead."

    We had lead calcium. We have lead selenium. Now lead tin. Batteries look like a Pandoras Box of mystery right now.

    Thought I was really unto something with "pure-lead." Hopefully I will dig in when my head clears a bit.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    I believe some folks here have talked about Optima as being "pure lead" batteries:

    https://www.optimabatteries.com/en-us/technology/spiralcell-technology
    The heart of OPTIMA® SPIRALCELL TECHNOLOGY is a series of individual spiral-wound cells composed of two pure (99.99%) lead plates coated in a precise coating of lead oxide. This breakthrough in battery design delivers more power and consistently outperforms conventional flat-plate batteries.
    You may have to be careful with the charging current--I think I recall that these require >20% recharging rate for long life(?).

    Anyway, here is an old thread about Optima:

    http://forum.solar-electric.com/discussion/21972/question-about-bulk-boost-float-charge-of-my-charge-controler-and-blue-top-battery

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wrcsixeight
    wrcsixeight Registered Users Posts: 4
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    Are there other AGM manufacturers than make the thin plate pure lead batteries other than Odyssey and Northstar?

    I've always done a bit of an Eyeroll when spiral cell batteries are used in a stationary or deep cycle application.  The extra vibration resistance iof the spiral 6 pac design is hardly necessary, and loss of 25%of the capacity for the same space seems a bit asinine, but marketing wins again..

    Regarding charge rate on AGMS, well I think even the AGMS that say to limit initial current to no more than 30% of capacity (20hr rate) benefit from initial charge rates upto this level.

    Is it that high amperage forces the migration of electrolyte through themattng/ plates better, or the heating of the battery from higher charge rates that is beneficial., some combination of both?  Is it even beneficial in the 30% limited AGMs when cycled deeply?

    I can only report my own observations with my Northstar AGM now in the 450 deep cycle range and 37 month s of use.

    It does not like low and slow solar only recharges when discharged to less than 65%.  After about 5 cycles the voltage held  for the same Ah removed during overnight loads starts dropping more and more.  This is true even if the solar has the time required to hold 14.4 to 14.7v until amps taper to 0.5% of capacity.  Technically fully charged, but the voltage held under load is not as impressive and each cumulated cycle after 5 it just gets worse.  It is reset by applying 40+ amps when most depleted, and this is not just battery temperature related because a high charge rate heated the battery, as it applies to the next night as well when any heating from a high charge rate has dissipated.

    After a 40 amp or higher recharge from ~50% charged, not only does voltage held under load  overnight improve, but voltage held during  cold engine cranking is also higher, and it cranks the engine noticeably faster too.

    If it has been many cycles with low and slow solar only doing a majority of the charging, then when I do apply high amperage, the amperage required to reach absorption voltage is lower as well.     When new I could stuff 106 amps into this depleted AGM and voltage would not quickly rise to 14.7.  The other night 60 amps brought it upto 14.6 quickly, but then it stayed there for 5 minutes, actually dropped to 14.5 still at 60 amps then took 10 more minutes  at 60 amps to rise to 14.7v at which point amps started tapering.

    The next night I was did another 50% discharge and applied 60 amps and the voltage rose fairly quickly to 14.5v at 60 amps, then fell to 14.1v at 60 amps, then held 60 amps for about 20 more minutes before it reached 14.7 at which point amps tapered.

    So the second High amp recharge in a row revealed the battery could accept high amps for longer before voltage limiting kicked in.

    The battery started out at nearly the same temperature both nights.

    To me this reveals the battery enjoys high amp recharges and more than just once.

    Is it the only AGM which does?  Well Odyssey say no less than 40% rate when cycled to 50% or less, and lifeline flat out states as high a rate as possible should be employed.

    But this is a solar forum.  Solar cannot start out at high rates. When the sun is strongest, hopefully the batteries are already well into absorption and accepting few amps.  But this slow ramp up is not the same as flipping a switch and achieving a 40% charge rate, and most solar installs use the 5 to 13% often  recommended charge rate.

    So this would seem to disqualify AGMS as good 'solar only' recharge batteries, but is the qualifier 'when discharged to 50% or less'? 


    I have to admit to Bias as I started reducing capacity in a deliberate attempt so that my solar maximum current at june 21( ~13 amps) could at least approach the 'recommended' recharge rates of the flooded marine batteries I was using.  And it seemed to work As one group 31 cost less than 2 group 27's, and I got 18 months from one 31 where with  2 27s I was getting 2 years before performance tanked.  but my ability to achieve and hold absorption voltage had also improved during the 31's life.


    Here is some partial vindication of that theory where Rolls Surrette says:
    [quote]The first phase of the charging process is the bulk charge. This is when the maximum amount of current flows into the battery bank until a desired voltage is reached. The recommended charge current is 10%-20% of the AH capacity of the battery bank, based on the 20 Hr AH rate (C20). Higher current levels may cause the battery bank to overheat. A lower current may be used; however, this will prolong charge time and increase the potential for sulfation build-up.[/quote]

    source: page 10
    http://rollsbattery.com/wp-content/plugins/rollsbatteries/pdfs/Rolls_Battery_Manual.pdf

    page 26 in the AGM section ups the rate recommendation to a minimum of 20% charts it for 25% and a 35% maximum.  I think Full river AGMS are Rolls surrette madein china. not sure if Rolls makes AGMS in Canada too, but perhaps rolls agm and full river are one and the same, one with a red case one with a blue.  I don't know.

    And further down in the renewable section (page 33)they say this:
    [quote]Batteries which are discharged should be recharged as promptly as possible. A Renewable Energy PV system should be designed to provide a charge current that is capable of recharging the batteries quickly, efficiently and within the window of time when the system is generating peak power (peak sun). The charge current should be within 10-20% of the 20 Hr AH rate (C20) rate of the battery bank, or the C4, C5, or C6 rate of the battery. Using the Absorption charge time calculation ( charge current of 10% of the C20 rate of the battery bank will take approximately 4.2 hours, plus the untimed bulk phase (usually about 1-2 hours) to bring the bank from 50%-100% state of charge. This is an ideal scenario as a lower charge current will often result in deficit charging as this increases the required Absorption charge time and/or the use of supplemental charging such as a generator[/quote]

    Now much of this refers to flooded batteries, but the recommended rates are still pretty high.

    So Much is made about returning 104 to 113% of the amount taken out, but I feel the rate at which that 1XX% is returned is just as important, especially with AGM's.

    My TPPL AGM responds best to high amp recharges, and I Apply them as often as convenient, or when it has been a while without one, I will go out of my way to do a 50% or deeper discharge and make sure I hit them with an instant 40 amps or higher from their most depleted state.

    I would love it if it did not require this, but honestly in my application with 200 watts of solar, 108 available amps of alternator and 40 or 65 amps of plug in charging source, I have been able to keep this AGM performing well for its 3+ year lifespan and 450 deep cycles with many of those cycles well below that 50% discharge level. it is less work than the previous flooded group 31 required with 16v eq sessions every 14 to 16 deep cycles.

    I think the trick is  a big charge rate with AGM to a huge extent, and to a lesser extent with flooded.  Perhaps not every recharge, but say once every 5 to 7 deeper cycles then go out of one's way to achieve at least a 20% charge rate from the most depleted state.

    I am not really happy with Northstar's  PDF/user manual.  They do not state anywhere where a high amp recharge should be considered only that it can accept high charge rates, but Odyssey outright does say 40% when deeply cycled, Meet it or Suffer.  I have tried to treat my Northstar according to odysseys recomendations as they have so many of the same claims as to capacity and weight and CCA. I can achieve 40% to 58% with plug in charging source.  I could/can achieve well over 100% rate with the alternator,, on june 21 at noon,  via solar, I can achieve about  15%. but hopefully by noon I am already well into absorption.

    I also notice after the high amp recharge from the most depleted state that it takes less time for amps to taper to 0.5% of capacity regardless of the charging source.

    So again the OP stating that it takes 8 hours to replace 18AH on his 11.5 year old lifeline, well perhaps too it is just craving a high amp recharge or 3 from a more depleted state to wake back up.   The Lifeline is not TPPL, but they do state that there is no easily achievable upper limit on charging amps so let those amps fly.  They did not fly, the battery is not happy nor performing well.

    Perhaps high amp recharge rates from 50% at this point is too little too late, but perhaps not.  Nothing to lose by trying.

    On some other  RV based forums I've read about poor performance from Lifelines, but the owner only had a slight amount of solar abd rarely applied other charging sources., but then went on to say then only used a small portion of the battery capacity, that they were in float every day and  did not need more solar.

    Hard to teach people that float does not necessarily mean fully charged, and certainly even harder to convince them that a higher charge rate is a good thing, when grandpa once said repeatedly, 'put it on a trickle charger'

    I say with AGMs, blast them with a minimum of 29.9% from their most depleted state, once ever 5 to 7 deep cycles.  And hopefully that most depleted state is below 60% SOC so the battery can accept 29.9% for at least 35 minutes.  My opinion.








  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
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    Don't forget the most common pure-lead / tin : Optima.  Prior to that was the Gates Cyclon which you can still get, but under the Enersys name now.

    If you want, you can go back to the days of yore when EV's ran a truck-bed full of Optimas, or Hawker/Enersys Genesis pure-leads.  Seek out the EVDL list, and keep an eye out for Lee Hart and crew in the threads.

    Just remember that this is an EV application (well retro for the most part), far different from our low-current housebank application.  BUT, if you read carefully, you'll note that without an EQ, or in our case at least a "freshening charge" for an AGM, be it a standard lead-calcium or pure-lead / tin, they get bored and start losing capacity. :)

    Be sure to see Plasma Boy's Racing "White Zombie" drag EV.  Find out why they called themselves Plasma Boy when a wrench got dropped.

    From a historical standpoint, one will see all the signs of what we have been going through with LiFeP04 bms / balancing.  Our dragstrip forefathers have already been there with agm! :)