New batteries, low specific gravity. What does this mean?

awade
awade Registered Users Posts: 14 ✭
in Off Grid Solar & Battery Systems #1
Out here in Hawaii, battery options are limited due to exorbitant freight costs. I offered to buy 16 rolls-surrettes from a mainland dealer but when I told him about local interstate battery price, he told me I'd be better off buying the Interstates to save on freight. So I did.

Very excited to start with a fresh battery set after abusing the first one. Picked up sixteen 415ah L-16's and tested specific gravity on each before wiring everything together in 48V config. While each batt showed 6.2V, specific gravity was between 1.22 and 1.24. I bought a different hydrometer to double check and got the same readings. Charged for 24 hours (Absorb 58.6V, Float 54.4V) which brought S.G. to 1.25-1.26. Called the manufacturer and they said they had charged them before delivery but admitted that they should read 1.27-1.275. While Interstate could not give me charging specs in voltage, only in current ( 4-8 amps??), they recommended that I equalize for 2 hours using spec I offered (62.4V) and then do a 30 hour charge with low amperage (6amps). I'm doing this now.

2 questions:

1) I noticed a sulfur smell during equalization. It's been suggested that this shouldn't occur with new batteries. Does this mean there is already sulfation?

2) Even if this process yields a higher specific gravity reading over time, are these signs of future trouble? Should I exchange for new batteries? They're around 2000lbs; it took me 7 hrs to pick up, load and wire everything so I'd like to avoid an exchange but absolutely will do it if it's the right thing to do. That said, I have no way of knowing if the new ones will be anything other than overcharged cells because they knew I was coming.

Too bad that this isn't turning out to be the "fresh start" I had hoped for.
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Comments

  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #2
    Re: New batteries, low specific gravity. What does this mean?

    I wouldn't worry, what you smell is normal during a EQ charge. The fact that they were a little low on delivery should not effect them long term, that is the reason to do a EQ charge in the beginning with a new bank so you can get a baseline to work from. You will know the point you have to get back to. Pick a couple pilot cells that you can sample. Did they tell you what the SG of the electrolyte that was put into the batteries ?? If your shooting for 1.275 and they were filled with 1.26 you may never get there. Interstate has some weird charging perimeters anyway, they almost want you to do a EQ on every absorption cycle.

    This off their web site, I challenged them about the voltages and their engineer stood by them.

    Attachment not found.
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #3
    Re: New batteries, low specific gravity. What does this mean?

    Hi awade,

    The sulphur aroma, in my opinion, is normal for batteries needing an EQ. It should diminish as the EQ proceeds.

    They really do want a HOT charge, and as BC mentioned, the Absorb is really an EQ every day. These batts prbably have been sitting off-charge for some time, but if the voltage of each battery was fairly even (before you started EQ/charge) then probably not a problem.

    YES, you should ask just what is the target SG for these batts, but from my ecperience, it does look like it is 1.277 ish SG.

    If you have not done so, you should measure and record the resting V, and SG of each battery, and record it in your batterty Log. As BC mentioned, choose at least one Pilot Cell (usually the lowest SG cell). This Pilot will help you quickly determine the SOC of the bank. Initially, you will probably want to measure the SG of each cell fairly often in the first few weeks, until you know how the batts like to be charged, be sure to record these readings in your log, with the date. It is best to measure the bank SGs just when the bank gets to Float.

    Just my opinions, Good Luck with the new bank, 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.
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  • awade
    awade Registered Users Posts: 14 ✭
    #4
    Re: New batteries, low specific gravity. What does this mean?

    Thanks for the assurance. I'm glad to hear that the sulfur smell is normal. I thought it didn't occur till much later in the battery life.

    The head tech at interstate said that upon delivery, they should be reading 1.27-1.275 so it appear safe to assume that 1.275 is the target . He offered a very humble apology and mentioned that I should equalize if ever they drop below 1.27.

    I've seen that same web page from Interstate. I agree that their charging parameter seem highly suspect. In 48V terms, Absorb at 62V and EQ at 62.4V seems like your just boiling daily. I mentioned this to the tech at Interstate and he strongly agreed that you wouldn't want to EQ every day but he couldn't give me any better numbers to work with because he works in current only. He did mention that he has 12V batteries regularly charging at 16V but I don't know what to make of that. Maybe they just love to EQ over there. I, on the other hand want this expensive investment to last as long as possible. The settings I've plugged in to my Outback FM80 are: Absorb 58.6, Float 55.2 and EQ 62.4. Does this sounds reasonable? Batteries are too far away from the CC for an RTS but the ambient temp here is generally between 73F and 87F. If anyone has had experience with these batteries and has better numbers I'd love to hear them.
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  • awade
    awade Registered Users Posts: 14 ✭
    #5
    Re: New batteries, low specific gravity. What does this mean?

    Hi Vic,

    So, in your opinion, that HOT charge they require means I really should set the CC to Absorb at 62V?

    Thanks for the tips on logging SG. I'll do as you suggest. Just to clarify, should I check SG on each cell of each battery or will the center hole of each battery suffice? Also, does it matter if the pilot cell is near or far in the chain from the charger cables?

    A final question while I'm asking questions, is it still advisable to rearrange to batteries every couple of years or is EQing enough?
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #6
    Re: New batteries, low specific gravity. What does this mean?

    "Batteries are too far away from the CC for an RTS but the ambient temp here is generally between 73F and 87F."

    this could be a problem and not so much because you don't have an rts, but because voltage drop from the cc to the batteries can set up a low charge to the batteries depending on the gauge of the wire, the length of the wire, and how much current passes through it. most rts cables can go about 15ft and i don't remember what the length of it is off hand. you must be certain your wire isn't undersized.
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #7
    Re: New batteries, low specific gravity. What does this mean?
    niel wrote: »
    "Batteries are too far away from the CC for an RTS but the ambient temp here is generally between 73F and 87F."

    this could be a problem and not so much because you don't have an rts, but because voltage drop from the cc to the batteries can set up a low charge to the batteries depending on the gauge of the wire, the length of the wire, and how much current passes through it. most rts cables can go about 15ft and i don't remember what the length of it is off hand. you must be certain your wire isn't undersized.

    Use the same voltmeter to measure the output voltage of the charger and the voltage at the batteries. See what the voltage drop is at full charging current and during Absorb. Unless you use a pair of remote voltage sensing wires from battery to CC (not at all common) you can either increase the voltage settings of the CC for Bulk and maybe Absorb (but not for Float!!!!) or increase the size of the connecting wires.
    SMA SB 3000, old BP panels.
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #8
    Re: New batteries, low specific gravity. What does this mean?

    Hi awade,

    I think that your Float voltage setting in your chargers should be about 52.8 V (from 2X the 24 V listing in the table BC supplied).

    One way to try to get the Float V correct, is to measure the SG when you just go into Float, and measure it again when you are just about to fall out of Float (larger banks respond slowly, so this does not always work well). If you maintain SG, it is about correct. Trying to set this V on the low side of things ... ie just barely maintain SG would be best. My opinion on this drifts a bit ... I am now considering setting Float a bit below maintenance voltage, to try to be a bit more gentle on the batts. If one gets into Float on most days, this should not hurt anything.
    Just opinions, 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.
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  • awade
    awade Registered Users Posts: 14 ✭
    #9
    Re: New batteries, low specific gravity. What does this mean?
    niel wrote: »
    "Batteries are too far away from the CC for an RTS but the ambient temp here is generally between 73F and 87F."

    this could be a problem and not so much because you don't have an rts, but because voltage drop from the cc to the batteries can set up a low charge to the batteries depending on the gauge of the wire, the length of the wire, and how much current passes through it. most rts cables can go about 15ft and i don't remember what the length of it is off hand. you must be certain your wire isn't undersized.

    Hi Niel,

    I actually have an RTS(outback) but it won't reach the batteries (30ft) and since it has an ethernet type connection I don't know how to extend it. I moved the batteries away from the house because, after a little research, I started getting paranoid about hydrogen sulfide wafting into the house as they age. The wire from the bank to the CC is 30ft long but it's 4/0 so I think it may be okay. Any thoughts?
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  • awade
    awade Registered Users Posts: 14 ✭
    #10
    Re: New batteries, low specific gravity. What does this mean?
    inetdog wrote: »
    Use the same voltmeter to measure the output voltage of the charger and the voltage at the batteries. See what the voltage drop is at full charging current and during Absorb. Unless you use a pair of remote voltage sensing wires from battery to CC (not at all common) you can either increase the voltage settings of the CC for Bulk and maybe Absorb (but not for Float!!!!) or increase the size of the connecting wires.

    Hi inetdog,

    I'll check the voltage again at both CC and batts. Currently the CC shows a higher voltage than my voltmeter reads at the batteries but I take your point, using the same meter at both locations will tell me what the loss is.
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  • awade
    awade Registered Users Posts: 14 ✭
    #11
    Re: New batteries, low specific gravity. What does this mean?
    Vic wrote: »
    Hi awade,

    I think that your Float voltage setting in your chargers should be about 52.8 V (from 2X the 24 V listing in the table BC supplied).

    One way to try to get the Float V correct, is to measure the SG when you just go into Float, and measure it again when you are just about to fall out of Float (larger banks respond slowly, so this does not always work well). If you maintain SG, it is about correct. Trying to set this V on the low side of things ... ie just barely maintain SG would be best. My opinion on this drifts a bit ... I am now considering setting Float a bit below maintenance voltage, to try to be a bit more gentle on the batts. If one gets into Float on most days, this should not hurt anything.
    Just opinions, Vic

    Hi Vic,

    Thanks, you're right. I missed that on the Float setting. I've reset the float to 52.8V. Sorry for my ignorance but I'd like to better understand: which of the settings is the "maintenance voltage". Still wondering if I should going for that astronomical 62V absorb and, if so, how long, or should I leave it at 58.6V for 4 hours.
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  • awade
    awade Registered Users Posts: 14 ✭
    #12
    Re: New batteries, low specific gravity. What does this mean?

    I really appreciate everyone's input.

    I just completed my second 30 hour charge in 4 days, after EQing at 62.4V. Specific Gravity is reading 1.275 in the center cell of all batteries except for the three closest to the Positive CC connection. They read 1.265. Still below the 1.275 target. At the time of the reading they were in Float at (55.2V) with a minor load and lots of extra sunshine. I wonder if the small load was enough to make those three batteries lower. Seems like after 4 days of steady charging the batteries should have balanced by now.

    Float is now set to 52.8
    Still not sure what to set Absorb to and for how long.

    I have around 60 Amps of solar to push into these batteries but the Interstate Tech was telling me that low amperage is better. Like 6 amps. He says high amperage will wear our the batteries more quickly. Problem is, with this many batteries, if I lower the current limit on the FM80 to 6 amps there's no guarantee that I'll ever get to a 62V Absorb. Currently I've limited the CC to 24 amps.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #13
    Re: New batteries, low specific gravity. What does this mean?

    Setting aside my personal opinion that Interstate batteries are crap ...

    6 Amps is a fine charge rate - for a 60 Amp hour battery.
    10% of the battery bank capacity is a nice target for peak charge current. This does not mean it will be 10% all the time, or possibly ever; if the batteries don't need it, they don't get it.
    You have two parallel strings of 415 Amp hours each? There's no reason they shouldn't be able to take 82 Amps peak current. If they can't, they're crap. (OOPS!) Obviously 6 Amps isn't going to do much for them at all; it's only 1.4% rate. That's a float charge (keep ahead of self-discharge).
    Interstate does specify some very high Voltage for Absorb on their batteries. Even higher than Trojan. 60 Volts would not be unrealistic by their standards.

    How long the Absorb should be will depend on how deeply you discharge them. Considering there usually is about a 5 hour "window of opportunity" to get through Bulk and Absorb, you probably can't have longer than 2.5 hours of Absorb. If the Bulk rate is good it shouldn't take that long. If you set End Amps it should be about 8 to 10, plus whatever constant loads are there (as in keeping the inverter running).

    Clear as mud?

    Oh and start saving for the next batteries you'll need to buy when these ones mysteriously fail after two years. :roll:
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #14
    Re: New batteries, low specific gravity. What does this mean?
    Cariboocoot wrote: »
    How long the Absorb should be will depend on how deeply you discharge them. Considering there usually is about a 5 hour "window of opportunity" to get through Bulk and Absorb, you probably can't have longer than 2.5 hours of Absorb. If the Bulk rate is good it shouldn't take that long. If you set End Amps it should be about 8 to 10, plus whatever constant loads are there (as in keeping the inverter running).

    Clear as mud?

    Oh and start saving for the next batteries you'll need to buy when these ones mysteriously fail after two years. :roll:

    There are those (who shall remain nameless here) who argue that, since the charging time is limited, the proper strategy is to keep the batteries in Bulk mode for the whole time if possible, going directly to float if you reach a high enough voltage, and forgetting the Absorb phase completely. This is a winning strategy if the batteries are discharged enough that you cannot have the luxury of three stage charging within the solar window of opportunity. Like in Winter. How you fool your CC into doing that (and whether you can) will vary from CC to CC.
    SMA SB 3000, old BP panels.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #15
    Re: New batteries, low specific gravity. What does this mean?

    Not a good strategy in my book, but chacun à son goût. :D
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #16
    Re: New batteries, low specific gravity. What does this mean?
    Cariboocoot wrote: »
    Not a good strategy in my book, but chacun à son goût. :D

    The favored strategies change when you have a generator which can be used to make sure the batteries get to full charge eventually from time to time.
    If your only charging option is the panels, it becomes a more interesting argument. But there definitely is no consensus even then.
    SMA SB 3000, old BP panels.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #17
    Re: New batteries, low specific gravity. What does this mean?
    inetdog wrote: »
    The favored strategies change when you have a generator which can be used to make sure the batteries get to full charge eventually from time to time.
    If your only charging option is the panels, it becomes a more interesting argument. But there definitely is no consensus even then.

    Well we do things differently up here in the Great White North: with panels and generator the strategy is to Bulk with gen when necessary and hope the panels have enough exposure to finish the charge. When the gen isn't necessary the panels can do the whole job. Having to run a full charge cycle off generator alone is expensive.

    And for some reason our electrical tape is shiny silvery-gray. :p
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #18
    Re: New batteries, low specific gravity. What does this mean?

    Coot, I think Red Green is looking for you too...lol
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #19
    Re: New batteries, low specific gravity. What does this mean?
    westbranch wrote: »
    Coot, I think Red Green is looking for you too...lol

    Heh, heh. You've never seen a picture of me. :D

    Remember; if the women don't find you handsome they should at least find you handy!
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  • TheBackRoads
    TheBackRoads Solar Expert Posts: 274 ✭✭
    #20
    Re: New batteries, low specific gravity. What does this mean?

    I just saw Red Green do stand up a few months ago. Hilarious. He said "thanks for supporting a rediculous show, I had a lot of fun" hahaha
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #21
    Re: New batteries, low specific gravity. What does this mean?

    You want t watch one of the series just to see how an engineer (red really is an engineer turned comedian ) can dream up uses for 'Duct tape' http://en.wikipedia.org/wiki/The_Red_Green_Show#Red_Green
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #22
    Re: New batteries, low specific gravity. What does this mean?

    Maybe the Interstate person meant 6 amps x 16 = 96 amps on a daily basis. Before EQ'ing, the batteries should have just gone through a Full charge cycle to float. I have never seen the amps go up more than 8-10 amps to raise the voltage the 1.5 to 2 volts required to get to EQ voltage and less to maintain it.

    I bought 10 Interstates from a guy that were a year old for the core charge. I hooked them up and EQ'd them 3 times. I am on my second year with them and they show no sign of any issue. If your EQ'ing and you control the temperature's and the SG is rising you'll eventually get there.

    I was very disappointed with the answers that Interstate gave me, I think they are just covering themselves on the warranty period and could care less about the longevity of the batteries. The voltage they show on their chart is a EQ on every charge cycle. Maybe it's ok if most of us had a way to get there.
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #23
    Re: New batteries, low specific gravity. What does this mean?
    Blackcherry04 wrote: »
    I was very disappointed with the answers that Interstate gave me, I think they are just covering themselves on the warranty period and could care less about the longevity of the batteries. The voltage they show on their chart is a EQ on every charge cycle. Maybe it's ok if most of us had a way to get there.

    Interstate batteries are popular around here because of their price and distribution. They are made by US Battery and their charging profile is essentially what US Battery recommends. Most battery manufacturers base their charging profile on grid-powered battery chargers that can provide charging profiles that solar controllers cannot match.

    Interstate is a reseller. Their sales and tech folks don't know as much about batteries as a battery manufacturer does.

    read: http://forum.solar-electric.com/showthread.php?14738

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #24
    Re: New batteries, low specific gravity. What does this mean?
    vtmaps wrote: »
    Interstate batteries are popular around here because of their price and distribution. They are made by US Battery and their charging profile is essentially what US Battery recommends. Most battery manufacturers base their charging profile on grid-powered battery chargers that can provide charging profiles that solar controllers cannot match.

    Interstate is a reseller. Their sales and tech folks don't know as much about batteries as a battery manufacturer does.

    read: http://forum.solar-electric.com/showthread.php?14738

    --vtMaps
    This US Battery's recommended charge profile, it's completely different from Interstates. Even they have flakey voltages, look at their Float Voltage 13.02 @ 12 v . Should it be 13.02 or 13.2 ?? big difference.

    Attachment not found.
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #25
    Re: New batteries, low specific gravity. What does this mean?

    I had thought that the 6 amps, was Return Amps = End Amps for each string. But just a guess.
    Of course, the amount of current required to get from Vabs to Veq varies with the bank AH capacity and many other things.

    I do not know what I'd for charge voltages with Interstate batts. These batts have high SG electrolyte, so need a bit higher Vabs, BUT doing an EQ for each charge cycle seems like a very bad idea for RE use. Believe that these batts must in the Floor Scrubber application area, where they are run flat each cycle, and need to be quickly recharged with a Grid charger.

    These batts will use a LOT of water with the factory charge specs ... Be certain to watch the electrolyte levels carefully.

    Guesing done for now. 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.
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #26
    Re: New batteries, low specific gravity. What does this mean?
    Blackcherry04 wrote: »
    This US Battery's recommended charge profile, it's completely different from Interstates.

    They are not identical. I wrote that they are essentially the same because both finish their daily charge with a very high voltage (over 60 volts).

    Vic wrote:
    I do not know what I'd for charge voltages with Interstate batts.
    The installers around here who use interstate batteries set their absorb voltage to 59.2.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • awade
    awade Registered Users Posts: 14 ✭
    #27
    Re: New batteries, low specific gravity. What does this mean?

    Blackcherry04, thanks for the US battery specs. They are similar to Intersates. Is "finish charge" the tale end of absorb? They call for 2-4 hours that seems long to hold at 61.2V. Anywhere above 58V and I want keep the duration short so I'm not always topping off the water.

    vtMaps, 59.2V seems like a reasonable compromise instead of 62V. I'm currently at 58.6V, maybe I'll bump it up.

    What's interesting is that a low amperage (8A currently) combined with a high absorb voltage causes a slow and steady rise in charge until it drops fairly low to float at 52.8V. I wish I had some way to use all that extra juice from the panels that is being held back.

    For those that say Interstate's are crap, I know they don't have the best reputation especially given that in theory they require a larger solar array to manage a higher daily absorption voltage. If I weren't in hawaii, I'd probably getting some Surettes right about now. That said, I had my previous set of HC-L16's (absorb set to 55.2V) and they worked like champs for six years. This was after sitting with no charge the first year (because the panels were on backorder) and after allowing the plates to get exposed a couple of times as they aged while I started exploring higher absorb settings. In fact, the death blow came from the fact that my Outback MX60 CC stopped "seeing" the panels and let the batteries discharge over the course of a week when I was away. To keep the show on the road I replaced the CC with a FM80 only to discover that despite compete charging, the batteries would be down to 44V every morning. I knew that it was over.

    The upshot is, had I been a little more diligent about watering and had the MX60 held in there, it is very possible the Interstates would have given me a 7th or 8th year.
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #28
    Re: New batteries, low specific gravity. What does this mean?
    awade wrote: »
    Blackcherry04, thanks for the US battery specs. They are similar to Intersates. Is "finish charge" the tale end of absorb? They call for 2-4 hours that seems long to hold at 61.2V. Anywhere above 58V and I want keep the duration short so I'm not always topping off the water.

    vtMaps, 59.2V seems like a reasonable compromise instead of 62V. I'm currently at 58.6V, maybe I'll bump it up.

    I agree with Vic that the charging profile provided by US Battery is designed for small traction applications where the batteries are deeply discharged nearly every day. Their recommended profile uses an IUIa charging profile (constant current, constant voltage, constant current with voltage cutoff) which none of the renewable energy chargers can provide. This profile was designed to quickly charge a deeply discharged battery which is definitely not the case in most solar applications.

    Since RE chargers don't have a "finish charge" mode, you can just lengthen the absorb time at the normal 2.4V per cell, and then do a monthly EQ at 2.55V per cell.

    This same thing happens when you ask forklift battery manufacturers how you should charge their batts, since 99% of their clients use forklift batteries for forklifts, they recommend the charge profile for those users - which is not the same charging profile required for RE applications.
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #29
    Re: New batteries, low specific gravity. What does this mean?
    Vic wrote: »
    These batts will use a LOT of water with the factory charge specs ... Be certain to watch the electrolyte levels carefully.

    I highly recommend that you put some water miser caps on your interstates. They cut down on your water use, but much more importantly they reduce the amount of sulfuric acid mist that emerges from your batteries. That mist causes corrosion and can damage your battery box (if its made of plywood).

    NAWS carries one size (height) of water miser caps. I purchased mine from the manufacturer because I wanted the taller ones. (the taller they are the more effective they are). http://www.flowsystemsusa.com/water-miser-vent-cap.html

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • awade
    awade Registered Users Posts: 14 ✭
    #30
    Re: New batteries, low specific gravity. What does this mean?
    vtmaps wrote: »
    I highly recommend that you put some water miser caps on your interstates. They cut down on your water use, but much more importantly they reduce the amount of sulfuric acid mist that emerges from your batteries. That mist causes corrosion and can damage your battery box (if its made of plywood).

    NAWS carries one size (height) of water miser caps. I purchased mine from the manufacturer because I wanted the taller ones. (the taller they are the more effective they are). http://www.flowsystemsusa.com/water-miser-vent-cap.html

    --vtMaps

    Thanks for the link, vtMaps, I'll take your advise.
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