Weak cell issue solved!

home skillet

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I live off grid in Upstate NY. I have a 14400KW solar array, 4x Midnight solar charge controllers, 2x8048 Outback radians and a (1500 A/H, 6000 lbs,) 48 volt BBI "forklift" battery. and a 30KW Isuzu diesel generator

I was having issues with one cell always being 6 points lower (SG 1.22 vs 1.28) than the other 23. I could equalize the battery, but when I did, the other 23 cells would go up to SG 1.3 and hang there for hours waiting for the weak cell to catch up. The other 23 cells got very warm and I would shut down the equalization without truly equalizing. After the EQ was finished?? I'd have 23 cells at 1.29 and 1 cell at 1.26. I was looking for a way to charge the one weak cell at 2.5 to 2.6 Volts DC, without subjecting the other 23 to this voltage. 2.6 vdc applied to a single cell is "Equalize voltage".

Low and behold I found a company called Hindlepower out of Easton PA. They make a single cell battery charger that you can use while the battery is in service.....hooked up and powering your home. I was skeptical, but I bought one. It adjusted it to 2.6 volts / 10 amp output per instruction. Before I actually hooked it up to the weak cell....i thought....."at only 10 amps, this probably wont the moxie to bring the weak cell to 2.6 volts". Anyway, the weak cell was at SG 1.21 at this time and the other 23 were SG 1.25. I hooked it up to the weak cell and I was only getting 2.38 vdc going into the weak cell. I thought I had wasted 465 dollars. I left it charging the weak cell all day long. The test day was partially sunny, but far from clear, as far as solar charging goes. When the sun went down, I checked the SG's and I was shocked. The "weak" cell was now at 1.28 was the other 23 were at 1.27. IT WORKED. I can't honestly say it ever brought the weak cell to 2.6 volts........but I dont care. It did its job. It brought the weak cell inline with the others. That was one week ago and the weak "cell" still runs neck in neck with the other 23. I do think the weak cell is probably a weak cell by definition and will probably have to do this again every month or so (especially in the winter). I wont however, have to subject the other 23 to high temp and high voltage for hours in an attempt to bring the weak cell inline. Hopefully this can help someone out there dealing with a delinquent cell or two.

Single-Cell Charger · HindlePower; Model: BB0442-01. ...........Hindlepower will not sell to us lil guys directly. I bought it thru Dowd Battery in Buffalo NY and paid $465 for it.
 

home skillet

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I don't get it.. How is this single cell charger any different than a 10 amp power supply adjusted for 2.6 volts?
Actually there is nothing to get. A battery charger IS a purpose built power supply designed to charge batteries.

I never thought of charging 1 cell, with the power provided from the other 23, but that is what is happening here. Essentially, I am robbing peter to pay paul. Peter was richer than Paul,..... but no longer. (its kinda the Democrats tax scheme smile :unsure: ).

The battery doesn't have to be subjected to Equalization Voltage....to equalize it. I will EQ the whole battery at 62 volts occasionally , but much less often, now that the one weak cell is on par with the other 23

About buying a power supply, Do you know where to buy a power supply with a adjustable range of 1.8 to 2.6 volts that outputs say.........75 or 100 amps? If a 100 amp charger, i wouldn't have to charge for 12 hrs.
 

home skillet

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if anyone knows where I can get a power supply that puts out 30-40 amps at 2.6 vdc please send a link
 

OzSolar

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If anyone bumps into this thread in the future I would offer that my 25 years in the field have taught me that the first step is to actually properly charge and equalize your flooded lead acid batteries. Send me a message and I'll be glad to try to help if you have any questions but don't follow this advice first.
 

MurphyGuy

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if anyone knows where I can get a power supply that puts out 30-40 amps at 2.6 vdc please send a link

HTRC makes multi-chemistry hobby chargers that put out 10 amps for about $50. Some of them are dual chargers so 10 amps x 2 channels. You'd just purchase two of them and run in parallel. As an added benefit, they wouldn't over-charge the battery like a power supply could.
 

home skillet

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Better yet. just tell me the error in my ways. I have a 48 volt battery made up of 24 individual 2 volt cells. 23 of the cells charge just fine. One cell is delinquent........and it lags in Voltage and SG. Please explain how I am to EQ the battery. I know I can apply 61-63 volts and EQ the entire battery when only 1 cell of 24 needs it. Please dont say charge all 24.....as I know this. Please explain how to charge one cell. Thanks in advance
 

home skillet

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HTRC makes multi-chemistry hobby chargers that put out 10 amps for about $50. Some of them are dual chargers so 10 amps x 2 channels. You'd just purchase two of them and run in parallel. As an added benefit, they wouldn't over-charge the battery like a power supply could.
Id love 30 or 40 amps............the 10 amp charger works, but with a 1500A/H system, it is severely overmatched
 

MurphyGuy

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if anyone knows where I can get a power supply that puts out 30-40 amps at 2.6 vdc please send a link
You'd have to do some research to look at specs, but this one seems to do 30 amps x 2 channels. That's more than enough, and it can do from 1 to 8 cells with chemistries of

Li-ion Life NiCd NiMH LiHV PB​

 

home skillet

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You'd have to do some research to look at specs, but this one seems to do 30 amps x 2 channels. That's more than enough, and it can do from 1 to 8 cells with chemistries of

Li-ion Life NiCd NiMH LiHV PB​


Thanks for the input. I am wanting a 120 vac input (not 240) and 2.6 vdc output, Until i get, one ill settle for the 10amp battery charger I currently have as it works
 

home skillet

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An to be upfront.....ive only been doing this for 5 years........but my life (and heating my home) depends on it.
 

MurphyGuy

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Thanks for the input. I am wanting a 120 vac input (not 240) and 2.6 vdc output, Until i get, one ill settle for the 10amp battery charger I currently have as it works
The hobby chargers allow you to set the cell count and chemistry type.. so you would tell it is PB (Lead Acid), then its only a single cell.

The HTRC models are one of the very few that also allow you to over-ride the charge voltage and adjust it a little up or down.. This worked great for me when I wanted to charge my 480ah single cell lithium ion to only 3.9 volts instead of the 4.2 that most automatic chargers do.

I forgot to put the link in for the 30 amp model! DUH! It has 120v input or you can choose AC or DC input.

 

home skillet

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BTW. It doesn't take a rocket scientist or 25 years experience to charge a battery, whether its a 2 volt cell or a battery made up of 24 individual 2 volt cells. It take the right equipment and a limited amount of knowledge. My post was simply to let people know that there is an alternative to overcharging 23 cells to properly charge 1.
 

OzSolar

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Or you could just charge and equalize your flooded lead acid batteries properly to start with and they will stay healthy for decades.
 

home skillet

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I can charge all 24 cells of a 48VDC,1500 A/H FLA battery at 61-63 vdc OR I can charge a single 2 volt cell at 2.5 to 2.6 vdc. I can and do, do both,

Tell me specifically, what i am doing wrong? Tell me how I don't know how to EQ a battery? Tell me how to its wiser to use a "R/C hobby charger" (for remote control cars and planes that utilize a 1500 MILLI a/h battery) Tell me how this R/C charger will fare when it charges a battery 1000 times bigger than it is designed for. As a R/C charger its duty cycle is minutes and charging my forklift battery it will be hours and hours. Tell me it has a big enough heat sync to charge for hours on end?

In saying all that, maybe your R/C hobby charger will work, or maybe it will get so hot it will literally go up in flames. I bought a battery charger designed to charge a big industrial battery (single cell) and offered that tid bit of knowledge up to others. You come across like you are at the center of all knowledge with your 25 years experience........and then you suggest a R/C charger!!!!. Good God man!!!.....as my Dad use to say "the first liar dont stand a chance".

PS. To anyone following this thread that wants a little insight. My Hindlepower charger gets quite hot also after 8 hours of charging. I called the company and they said it is designed for loooooooong duration charging and has a big heat sync (which it does). They wouldn't use the word continuous but just said long duration. Also, if anyone does buy a R/C charger to charge a forklift battery.....lemme know how it works. Until such time, ill continue to be a dumbass and charge my battery per manufacturers instructions. I feel dumber for even going into this rabbit hole!!!!!
 
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