Question about bulk / boost / float charge of my charge controler and blue top battery

louisbanenslouisbanens Registered Users Posts: 16
Hello,

I have got a et3415n charge controller from EPsolar and a Optima Blue Top DC - 5.5, 12V 75Ah, AGM battery ( BT75DC)Attachment not found..

My controller has the choice of Sealed, Gel and Flooded (but I can also adjust al the voltage settings). In either case the charger has 3 stages: Bulk Charge, Boost Charge and Float Charge (see picture). However my Blue Top Optima charge description says this:

Alternator: 13.65 to 15.0 volts

Battery Charger (Constant Voltage): 13.8 to 15.0 volts; 10 amps maximum; 6-12 hours approximate

Float Charge: 13.2 to 13.8 volts; 1 amp maximum; (indefinite time at lower voltages)

Rapid Recharge: Maximum voltage 15.6 volts. No current limit as long as battery
(Constant voltage charger) temperature remains below 125°F (51.7°C). Charge until
current drops below 1 amp.

Cyclic or Series String Applications: 14.7 volts. No current limit as long as battery temperature
remains below 125°F (51.7°C). When current falls below 1 amp,
finish with 3 amp constant current for 1 hour.

Any ideas what the best settings would be for the charge controller. For the Sealed option the charger has 15.5V for bulk charge, 14.4V for boost charge and 13.8 for float charge.
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Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Welcome to the forum.

    Which bad news do you want first? That you've bought the wrong battery or that you've bought the wrong controller?

    Let's look at the controller first. It's good that you can program the Voltages. Can you program anything else? Current limit? End Amps? Absorb time? Oh there's a clue: what the RE industry calls "Absorb" they've labeled "Boost". Inaccurate terminology is not a good sign. Bulk Voltage setting is another clue: the Bulk stage should push as much current as possible to bring the battery up to the Absorb Voltage level; it should not have its own Voltage rating. It definitely shouldn't be higher than Absorb and you sure don't want a 12 Volt system 15.5 Volts with sealed batteries.

    Now about that battery. Some Optimas are usable for RE applications. The one you have is an RV/Marine type, and though called "deep cycle" is not truly suited to RE. The yellow top one is what you should have got for this purpose. In either case they are AGM's: "sealed" batteries for your controller. They have a fairly good Voltage range, but I would start with the 'standard' 14.4 Volts for Absorb ("Boost"). Watch the current maximum because it isn't supposed to exceed 10 Amps by their specifications. If it does, lower the Voltage. If it doesn't, raise it. Use 0.2 Volt increments. Definitely do not go above 14.8 for this setting. Too much and the vent will probably pop and you'll lose acid. This is not recoverable on sealed batteries.

    Float at 13.8 Volts is pretty much normal for a 12 Volt system (many vehicles use this as a standard operating Voltage). Equalization should be disabled.
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Thanks for your reply.

    I have been told that this battery is internally exactly the same as a yellow top (see https://www.optimabatteries.com/en-us/support/faqs). Thats why I choose this one because it has extra connectors. I only can set voltage. No current limit. I can however limit (only) the boost time.

    You say there's a 10 amp limit. But for the Rapid Recharge and Cyclic application it says there's no current limit. Do you know what cyclic application means?
  • louisbanenslouisbanens Registered Users Posts: 16
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Internally the same in basic construction: cylindrical plates. So is the red top which is a SLI type. But by the same token standard deep cycle and automotive batteries are the same in basic construction. It's the subtle differences that make them more suited to one application or another. I'm not saying it won't work, but how well it will work depends on what exactly you want to do with it.

    The 10 Amp current limit is by their specs. Note that the "no current limit" for rapid charge comes with the advisory of not allowing the battery temperature to exceed 125F. That is the main reason to limit current: to prevent thermal runaway (cooked battery - can explode). In essence it's the same thing.

    The "cyclical application" is just what Renewable Energy is about: drawing down over several hours and then recharging over time (as opposed to the quick, short, but heavy discharge of starting followed by immediate quick recharge).

    You can't limit current on your controller, but you can limit it via the source that feeds the controller. Assuming that's PV all you need do is calculate the peak charge current potential with reasonable allowances. With a PWM controller it's easy because current is never higher than what the panels can supply, so you get 10 Amps * 17.5 Vmp (typical) = 175 Watts of panel. With an MPPT type (which the EPsolar is supposed to be) you need an efficiency factor. This is typically 77% so you get 10 Amps * 12 Volts / 0.77 = 156 Watts. Frankly the system is a bit small to justify MPPT so I hope you got a good deal on it.

    You should watch how long it takes to do the Bulk portion of charging and use that time as the limit for the Absorb (Boost) stage. You may have to adjust the number a bit when in use. Too long a period will subject the battery to excess high Voltage time which is not good, too short a time will prevent it from being fully recharged. It's all about balance.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    BTW I just went searching for prices on that controller. The best I found was $269. The worst $419. That's quite a range. Even the best isn't good when you consider the top-of-the-line MidNite Kid 30 Amp MPPT controller is $285 from our host.
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Thanks, I have the battery for daily use of my laptop and lights. My panel is a Solar Frontier 170w panel with 87V nominal voltage and 1,9A nominal current.
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Oh yeah, how do I know if my battery is fully charged?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte
    Oh yeah, how do I know if my battery is fully charged?

    You don't.
    That is the big problem with sealed batteries: you can't check the specific gravity so you have to go by resting Voltage or adjusted usage Voltage and hope it's right. This is why battery monitor are a good thing to have with sealed batteries, providing you set everything up right to begin with.

    To that end you can charge the new battery 'gently' with no load until its current demand doesn't drop anymore. Then disconnect it and wait a day. Then measure the Voltage. That would be your baseline resting Voltage. A real pain in the anatomy to track SOC from that, so you either put in the battery monitor giving it accurate numbers for capacity and Peukart curve or you apply your base load to the battery and see how much the Voltage sags. From then on it's a matter of really on the somewhat inaccurate Voltage with base load to determine if its fully charged or reading the battery monitor.

    As a compromise for small systems MidNite makes a battery meter which is something of a cross between these two methods: http://www.solar-electric.com/mnbcm.html Less expensive and less accurate than a battery monitor, more expensive and more accurate than a Voltmeter.

    You will be able to get close to knowing the SOC but no method (even a hydrometer) is 100% accurate. How inaccurate is a matter of how much shorter the battery life will be: a little inaccurate = a little less life, a lot inaccurate = a lot less life. On a small system like this you can afford a fair amount of inaccuracy. :D
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    I work with all the colors / flavors of Optima AGM with solar, and can say you want the "cyclic" type of operation.

    That is, set your bulk/boost to 14.7v. Set your float to 13.6v.

    Ok, so the Optima is not a dedicated RE battery, but it does fine in the casual solar application. Much better than a large ups-style agm.

    Do not just go by the labeling in your controller, pick the correct voltage. I'm also assuming your controller has temperature compensation, which is important. Best at the battery terminal, but otherwise ambient temp will have to do. If you have no temp comp capabilities, if you are in a hot region like 85+ degrees much of the time, set your voltages a bit lower, like 14.4v bulk/boost, and 13.5 float. Of course precise compensation is the word of the day.

    A little history might help explain things:

    Originally, the "tppl" or thin-plate-PURE-lead battery was introduced by Optima. Also near that time 1998 was it's nearest competitor, Hawker, which produced the much smaller (5-10ah) "Cyclon" pure-lead agm's. Later, Optima split off into Optima for consumers, and Odyssey for commercial interests. The visual difference is that the Optima retained the circular cell shape, while Odyssey went back to a more traditional flat-plate shape. Of course these days they are built by different manufacturers and have different internal chemical recipes.

    Optimas are built basically the same. The SLI versions (Red top and Blue top with black case) have a higher concentration of sulfuric acid in the agm electrolyte. The dual-purpose Yellow and Blue-Top / light gray case) are the same physically but have less acid in the electrolyte, but have convenient wingnuts for light duty connections. If you choose the Blue, don't get the black case unless you are doing just simple SLI duty.

    Originally, the charging specs for the Optima's were VERY detailed and oriented much towards the Electric-Vehicle market. Thus, rapid recharge capability with pure-lead was possible - the target time was 8 hours or less, but this necessitated high voltages and large current. Over time, the consumer may have been too confused by charging specs (much like the Odyssey's with their EXACTING specifications today - should be because basically they are the same chemistry overall, ie TPPL). Many good Optimas and Odysseys were ruined by either not understanding the charging specs, or using dumb chargers that had little to no voltage regulation. In the case of Odyssey, you can void the warrantee by not charging them with enough current, typically 0.4C *minimum*. Optima does not have this limitation. (but you ask yourself why since they are both basically tppl!)

    Optima over the years has tried to explain these charging details to the average consumer, but as a TPPL battery, it all depends on what you want to do with it.

    Solar in a cyclic application? Stick to 14.7v bulk/boost/absorb, and 13.7v float - temp compensated. Current? A TPPL-based battery can handle a LOT of current without getting too hot - because of it's extremely low internal resistance. This does not mean that you should charge unattended, nor pound it with HUGE currents without a voltage-limitation. Of course, this is with batteries that have not been damaged or previously abused.

    Consider that Optimas own charger does 12A, 2A beyond their "recommendation". Yet at the same time, these batteries are also used at the racing track, which may include no-alternator recharge capability. To get back in lane quickly for another run, you can hit them HARD, as long as you watch the voltage limit! Unbelievably, this means you can take them to 15.6v, but you will quickly reduce it's cycle life that way. Racing is a different world.

    Using pure-lead they have very low internal resistance and that's part of the reason they can handle a lot of current. BUT the safe person will not charge unattended, will be using temp-compensation, a proper upper voltage limit, and perhaps an IR hand-pointing temperature meter to see if any cells are overheating. But this may be too much for the average consumer, so a safe limitation of 10A is easy to remember.

    Being able to hit Odysseys, Optimas, and Hawkers with a lot of current is one reason I'd recommend them for casual use where you have little solar insolation, but have a lot of panel power to recharge them quickly. Being able to hit them hard can also save you generator fuel.

    The KEY issue is voltage. Not at the track? Then just keep your voltage to no higher than 14.7v, and make sure your current is reasonable. Personally, I go no higher than 0.5C, for which my D34M at 55ah means no more than 27A charge current. At that rate, when I measured mine with an IR probe, they got no higher than 5 degrees above ambient. I wish I had that much current via solar, but my little 80w panel does fine with it as long as I have enough solar insolation.

    Do not fear an Optima (or Odyssey or Cyclon for that matter). They are *designed* to handle a lot of current, as long as the operator has quality voltage-limiting gear and is doing it safely. If you do that, you will not witness any drama. Although they are well built, do NOT swing them around and dent the cells! This WILL cause a hot spot. Rough 4x4 handling is ok if they are in a sold battery holder, but will not survive if left to bang around the chassis - like most any other battery. Beware of clumsy shipping - always buy from a reputable dealer.

    TIP - do NOT USE Schumacher Speed-Chargers on these. Schumachers will go to 15.6v and unless you are at the track, or trying to revive a badly abused zombie battery, they are not your best choice for maintenance of normally functioning Optimas. Even if you set it for AGM, it can go to 15.6v behind your back, which unless you absolutely have to, is something to avoid.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    A little more History. Don't think the optima of today is the same one from the 1990's. They use to last 10 years and were worth the premium price, these days your lucky to get 5 years. Once Johnson Controls got them, it was to make $$ as cheap as they could. My last one went 2 years 2 months, right after their warranty ran out. I did say it was my last.

    https://www.optimabatteries.com/en-us/about/brand-history
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    From what I've heard, QC improved a LOT since 2007. I've had no troubles with them especially since they are pampered with good care here.

    Lots of choices out there for casual solar use. I'm not saying Optima is the absolute best, but if I wrote off every battery maker due to a few duds received here and there, I'd be using nothing but earth-batteries. :)
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte
    PNjunction wrote: »
    From what I've heard, QC improved a LOT since 2007. I've had no troubles with them especially since they are pampered with good care here.

    Lots of choices out there for casual solar use. I'm not saying Optima is the absolute best, but if I wrote off every battery maker due to a few duds received here and there, I'd be using nothing but earth-batteries. :)
    I did say " Premium Price " , when I pay 30-40% less for a run of the mill same size Deka AGM and it lasts 8 years and has a better warranty, I write it off as lesson learned. I agree with you, it's really not the best choice for Solar anyway.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte
    Oh yeah, how do I know if my battery is fully charged?

    Cariboocoot is right - unlike FLA's we can't measure specific gravity of each cell, so the SOC voltage is the closest we can get.

    An easy way to tell is to allow for at least 4 hours of NO charge, and NO load. Measure battery terminal voltage. Don't use a $5 shirt-pocket multimeter. :)

    If it is 12.8v or more, then you are fully charged. A nice new Optima with a full charge will actually read somewhere close to 13.1v.

    How about half-charged? Normally one doesn't want to go below 50% DOD. Again, with a 4 hour rest period, 50% DOD would be about 12.2V.

    Under load, it is a different story, but with very light loads such as you have, just try not to go below 12.2v while your circuit is active.

    For future use, know that agm voltage may indicate SOC, but NOT the health of the battery. You can have a badly abused Optima sitting at 13.1v, but as soon as you put just a tiny load like an LED on it, the voltage could drop rapidly. However if you treat your battery right from the start, the above is a good ballpark.
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Hey thank you very much for the thorough reply. I have a couple of questions:

    Is it 3.6 or 3.7 float charge (because you mention them both). Second what does 0.5C mean? And what do you mean with solar insulation.
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte
    PNjunction wrote: »
    If it is 12.8v or more, then you are fully charged. A nice new Optima with a full charge will actually read somewhere close to 13.1v.

    How about half-charged? Normally one doesn't want to go below 50% DOD. Again, with a 4 hour rest period, 50% DOD would be about 12.2V.

    What does DOD mean?
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte
    What does DOD mean?
    Depth Of Discharge.
    A fully drained battery (the voltage has dropped below the specified cutoff point) will be at 100% DOD. A fully charged battery will be at 0% DOC.
    The complementary number is State Of Charge (SOC). That number is 100% for a fully charged battery and 0% for a fully drained battery.
    It pays to be careful when using or reading those values.
    And if somebody says "I am going to run that battery down to 25%" you cannot be sure whether he means 25% DOD or 25% SOC.:p
    SMA SB 3000, old BP panels.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Ok, here it comes...

    "C" means the 20hr rated capacity. My D34M Blue Top is rated at 55ah, so C=55. In your case, I believe you have a 75ah Optima. When I say 0.5C that's 0.5 * C, or put another way, C/2. When I fast charge my 55ah battery, I go no higher than 0.5C, or 0.5 * 55 = 27.5A from a charger.

    Solar insolation is the amount of "usable" solar light as compared to mere visible daylight. Solar charging is very weak during the early morning and late afternoon hours and is not used when you calculate your overall solar recharge capability. It also depends on your geographical location. To find yours, see this nifty set of graphs from NREL right here on our own forum host:

    http://www.solar-electric.com/solar-insolation-maps.html

    When figuring out your hours, many prefer to use the worst-case scenario to give yourself some headroom, which here would be the "Winter" hours. In Southern California, that would be about only 4 hours usable. Since my 80W panel only provides about 4.5A of current, the max I could put into a battery during this timeframe would be about 18ah or so. If I had your 75ah battery, and drained half of it away, with my current setup, I could never get that battery fully charged in a single day. There are more great examples from the gurus here that will help. It all starts with what your LOAD is, that is, how much power are you pulling, and for how long each day, and then you figure out your battery needs, and then how much panel wattage you need to get to a full charge.

    Which conveniently brings us to "DOD" or Depth Of Discharge. Basically it is how much capacity left in the battery. 50% DOD means the battery is half full / empty. 100% DOD means empty. 10% DOD means you have 90% left.

    Unlike the old days when EV was starting to take off, agm battery manufacturers initially hyped their batteries about how many cycles they could last going to 80% DOD. You may still see this in some cases, like Odyssey. However over the years we found out that was too deep of a discharge for reasonable cycle life, so nearly everyone uses and calculates their DOD to go no lower than 50%. Ideally, one strives to go no lower than 20-25% DOD for the most cycle life. For the simplest of calculations, one figures out how much power they draw each day, and DOUBLE that amount for their battery capacity needed - ie for the typical 50% DOD worst case setup.

    Ok, 14.7v bulk and boost (boost also known as "absorb") and then 13.7v for float because you are cyclic. If you were just letting this thing sit in garage doing nothing but floating its whole life, then Optima recommends lowering float to 13.5v. But you are cyclic, ie actually using it once in awhile. If you can't get these exact voltages, just try to get close - but that's Optima's somewhat looser specification stance. If you had an Odyssey, you have very strict voltages where even a 10th of a volt either way could get you into warrantee trouble. :)

    Note that i don't hammer my Optimas with 0.5C current from a charger all the time. They just sip on my 80w panel output of about 4.5A. However, since they are TPPL, my own tppl research indicates that giving them a decent charge current once in awhile is actually healthy for them, kind of like a deep-pore cleansing. So, about every month or two, I'll drag it down to about 60% DOD, and hit it up with my 25A AC charger. Just beware that there are chargers that are NOT within spec, or do things behind your back, so vetting their voltages, especially if they are not documented by the manufacturer are mandated. Either validate it yourself, or perhaps think along the lines of an Iota charger, which our host carries if you are interested.

    I like Optimas / Odyssey / Hawker Cyclons, but they are NOT "RE" or Renewable Energy deep-cycle. True deep cycle RE batteries have very thick plates and basically will provide many more cycles of deep discharge than our dual-purpose types do. Even though the Optimas / Odyssey/Cyclons have "tppl" or thin-plate-pure-lead, these thin plates of pure lead give a measure of deep-cycling as compared to other agm's, along with the ability to be fast charged / discharged as long as voltage requirements are met. The percentage of acid in the electrolyte determines an Optimas SLI or dual-purpose faux deep cycle capability.

    Some of the big players in the true deep cycle field are Rolls-Surrette, Trojan, Concorde etc.. But for now, your Optima will do just fine as a learner battery.
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Well thank you for the thorough reply again!
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    My pleasure. Note that I edited the second line in the post above to mean a battery's 20-hour rate, and not 20ah.

    In addition to your solar setup, having a decent charger for the Optima is a good idea as a backup, or for making sure it starts off and stays properly charged in case something goes wrong.

    Unfortunately, many places that sell Optimas also sell chargers that are NOT optimum for it. Optima sells their own charger of course. (Update - free or discounted Optima chargers if you bought yours in April 2014). IOTA is also good way to charge it. I have tested three Schumacher Speed Chargers, and they went over-voltage and were quickly taken out of service, despite using the agm setting.

    If you need something locally, I personally use a Stanley BC-1509 15A charger on my Optimas. It does so at the right bulk/boost/absorb voltage and also a good float voltage. The other automotive options it has I just don't use. If you watch their official Optima videos, the tech actually mentions that anything from 8 to 15A is ok, even though they just recommend 10A to keep it easy to remember. As a tppl battery, I have no problems hitting them with 15A from a charger. I use other chargers as well, but the Stanley is pretty easy to get locally at your home and garden store.

    Have fun with your Optima!
  • Desert RatDesert Rat Solar Expert Posts: 122 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Speaking of Optimas, I had a pair of Blue Tops in one of my IH Scouts that I replaced last year after 15 years of service. I currently have another two in a second Scout that were put into service in November 2000 and are still going strong. In both trucks, the batteries were/are wired in parallel with no isolator. I use them in parallel for running the trucks and winch work, and rewire them in series for 24VDC battery welding.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte
    PNjunction wrote: »
    "C" means the 20hr rated capacity. My D34M Blue Top is rated at 55ah, so C=55. In your case, I believe you have a 75ah Optima. When I say 0.5C that's 0.5 * C, or put another way, C/2. When I fast charge my 55ah battery, I go no higher than 0.5C, or 0.5 * 55 = 27.5A from a charger.
    Since there are some applications for which a rate other than the 20 hour rate is the standard measurement, you will also see C20 used to symbolize the twenty hour rate. Also sometimes written C20.
    Not to be confused with 20C, C/20 or any of the other totally different numbers. :)
    SMA SB 3000, old BP panels.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    heh, even Odyssey specs a litle different at C10..

    What I found maddening when I started out with TPPL AGM batteries - Optimas, Odysseys, and Hawkers, was the profound difference in loose specs for the Optimas, and tight specs for the Odysseys / Hawkers. They come from the same family lineage back to Gates rubber, and searching for ancient docs was quite revealing especially when lead-acid EV was the rage. I suppose the difference was due to the cultural difference between the two initial sales demographics, automotive consumers with Optima, and commercial / military UPS type customers with Odyssey.

    It is clear that they are not specifically designed for RE use, and for me, putting them into solar cyclic operations means that to keep them healthy, I have to adopt a bit of a different tactic - namely occasionally hitting them HARD, (something like 0.4C or higher) as long as you are properly voltage-regulated! That will get them up to 90% or so of SOC due to Peukert. They STILL need a slower current charge with a longer absorb, and longer float for internal cell balancing - something I can do easily with my typical 0.2C solar setup.

    Search for a pdf from NREL / DOE and using Optimas with high-charge currents to extend life entitled:
    "Charging Algorithms for Increasing Lead Acid Battery Cycle Life for Electric Vehicles"

    What we do have with solar, is the ability to precisely set our voltages, and can thus run higher recharge currents if we have the panel capability - especially helpful if you are in an area of low solar-insolation, something one may not be able to do with standard agm's, even high quality Trojan agm's accept no more than 0.2C. This is similar to the more common consumer agm's like Powersonic, Universal Battery, etc.

    Some may find this non-commercial (NO SALES) site of interest:
    http://www.wheelchairdriver.com/fast-charge-your-power-wheelchair.htm

    This guy lives on batteries as a paraplegic engineer. TPPL Optimas to Odysseys and now to Lifepo4 to power his custom chairs.

    This helped me get over my own initial fright of charging Optimas and Odysseys with a lot of current. As long as one is safe about it, no thermal runaway drama was experienced here - and that is even during 90F ambient temps. Of course I am temp compensated and using batts from a reputable dealer - no used / abused / recycled batts passed off as new, mishandled, stored for a year in the desert in a tin shed ....

    If one needs super fast solar recharging, then also look into Lifeline as well. In the end I'm brand-agnostic, and found that while not intended specifically for RE, Optimas and other TPPL's are ok to use with solar, but for the longest life, need some higher-current preventative maintenance charging once in awhile.
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Great thank you very much for all your replies!!
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    And I started a new thread (http://forum.solar-electric.com/showthread.php?23215-Which-switches-and-fuses-to-use-in-solar-panel-battery-load-setup) because it seemed quite different then this one. So please reply (:
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    After installing everything I have the following questions.

    The charge controller measured 12.8v for my battery at start and soon (half an hour or even less) the controller displayed battery was charged to 14,7v with 0,6amp boost charge current. Then when I put on my laptop (60w) the battery dropped soon to +- 13,2v and boost charge current to +- 2.3 amp.

    Is this normal? My feeling is that the battery should be charged a lot more but without load it goes to quickly to the 14,7 volt so the controller thinks it's loaded.

    It's a clowdy day so my solar panel (Solar frontier CIS 170w) is now only generating 40 to 80 watts

    The optima blue top (75ah) battery is new and I didn't used it before.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    Load on a battery slows down charging as some of the power from the array is diverted to the load, thus reducing the current to the battery. Your laptop may not have much of an effect here as it has its own built-in battery and if that is charged it will only draw what is needed for running the laptop at the moment.

    Batteries that charge quickly in Voltage are either not deeply discharge, or defective. It is an indication that there is not many Amp hours that need to be or can be put back. In and of itself it is not a definitive test of anything.

    Run the battery down (not completely dead of course) on purpose and then try recharging it. A 75 Amp hour battery with 7.5 Amps peak current (about 130 Watts of panel) should recharge from 25% SOC in one good day.
  • louisbanenslouisbanens Registered Users Posts: 16
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    At this moment my charge controller repeatetdly does an Over Voltage Disconnect at 16V. It does that once and every 20 seconds. When the sun hides behind a cloud the charge controller is boost charging around 1,5 amp and voltage 14.6v. Then when the sun apears the current goes to 8 amp and the OverVoltage Disconnect happens. I would think that th controller would decide to switch to float charging. Any ideas?
  • BB.BB. Super Moderators, Administrators Posts: 32,319 admin
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    What is the AH and voltage of your battery bank (i.e., 170 watts of panel, 100 AH battery bank @ 12 volts)?

    Any other charge controllers (AC charger connected to utility power, running a vehicle charger at the same time) connected?

    The first guess would be the charge controller is not adjusted correctly or simply bad.

    If you have too large of solar array (or too small of battery bank AH capacity), some controllers can over voltage the battery bank when doing the MPPT measurements/calculations. But it does not really sound like the problem in this case.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte
    At this moment my charge controller repeatetdly does an Over Voltage Disconnect at 16V. It does that once and every 20 seconds. When the sun hides behind a cloud the charge controller is boost charging around 1,5 amp and voltage 14.6v. Then when the sun apears the current goes to 8 amp and the OverVoltage Disconnect happens. I would think that th controller would decide to switch to float charging. Any ideas?

    You get what you pay for. In this case you got an EP Solar charge controller.
    Sorry, but I don't think they're any good.
  • mike95490mike95490 Solar Expert Posts: 9,511 ✭✭✭✭✭
    Re: Question about bulk / boost / float charge of my charge controler and blue top batte

    you may have a bad connection in your Controller-Battery wire.
    I started getting HV Disconnects about 2 months before I found a high resistance, BBQ'd wire in my ePanel.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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