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Weak cell issue solved!

FWIW, multi-channel hobby chargers can't be used simultaneously on the same battery/cell unless it is specifically documented it can do that. It will typically be listed as "synchronous mode."

The linked HTRC one definitely won't (I have one), and the HOTA probably won't either.

I have an iCharger 4010B Duo that does have a synchronous mode. Can use both channels to charge at up to 70A/1400W with other limitations, but it needs to be fed from DC with the input current limited to 50A.
 
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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?

I am telling you that. Some are made better than others. I've pulled/pushed 300Ah @ 25A with the units I have. One one is done, I immediately start the next - literally running days constantly aside from the switch to the next.

It's important to realize that 100A @ 2.5V is only 250W - this is a trivial amount of power for mid to high range hobby chargers. Even the cheap ones can run continuously for days at 10-20A @ 2.5V (50W max).
 
Mine Hindle runs continuously at 2.6 VDC outputting 13 amps. (it is rated at 10 amps, but will output 13). Ideally i'd like a charger that outputs 100 amps at 2.5 / 2.6 volts. What is the gauge of the wiring that carries 2.6 vdc 100 amps to the battery?
 
do you make these 1 gauge cables yourself or do they come with the charger? Is the output voltage adjustable in .1 volt increments?
i have to find one that runs on 120vac and outputs 2.6vdc at or near 100 amps for a PB battery
 
do you make these 1 gauge cables yourself or do they come with the charger? Is the output voltage adjustable in .1 volt increments?
i have to find one that runs on 120vac and outputs 2.6vdc at or near 100 amps for a PB battery

I'm confused by your question. I've made no claims along those lines. I answered your explicit question concerning wire gauge for the stated criteria, 2.6V, 100A.

I personally have a 30A hobby charger capable of single cell Pb charging of 2.5V in 0.01V increments. I fabricated 3' leads w/8awg superworm wire.
 
my bad......i never said you made you own cables......but when i look online i see the R/C chargers and they say cables sold separately. I haven't seen any 1 gauge cables.....thats all. I have to make a lot of my own cables out of 4/0 welding cable. Nothing wrong with making your own wiring.
 
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.

I seem to experience the same problem with my 24volt 220ah tubular FLAs. Please how do I charge a cell separately in a battery?
 
my bad......i never said you made you own cables......but when i look online i see the R/C chargers and they say cables sold separately. I haven't seen any 1 gauge cables.....thats all. I have to make a lot of my own cables out of 4/0 welding cable. Nothing wrong with making your own wiring.
you're good home skillet;

wire size dictated by amp demand and voltage range and desired max voltage drop drives the calculation. ideally voltage drop always below 3% even better below 1% volt drop

thanks for being here!
 
I seem to experience the same problem with my 24volt 220ah tubular FLAs. Please how do I charge a cell separately in a battery?
It totally depends on your access to the actual cell-level terminals. I googled 'tubular fla' real quick and i'm still not sure yet how hard that would be for you.

Can you post a pic of one of your batteries?

I never thought of charging 1 cell, with the power provided from the other 23,
This is exactly what all lithium battery BMS's do during 'balancing', although more specifically it discharges the highest cell into the lowest cell. But with lithium batteries cell level terminals are 'easy' in comparison to FLA, because unless you're looking at a 2.1V single cell 'battery' the cell level connections are buried inside a melted-shut 'water tank' and unless you're going to go in there and hook up 'laparoscopically' with tiny bendy robot arms through the cell vent cap, it's generally not easy to hook to the cell-level terminals.

Unless im missing something...?
 
This is exactly what all lithium battery BMS's do during 'balancing', although more specifically it discharges the highest cell into the lowest cell.

This is only party true with active balancing and varies by balancer. Most BMSs use passive balancing where resistors just burn off charge from the high cells as heat with a paltry 30-70mA.
 
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.
I am waiting for my Mean Well RSP-3000-12 power supply to be delivered
It is supposed to supply 2.4 - 13.2 Volt at up to 200 Amp.
 
This is only party true with active balancing and varies by balancer. Most BMSs use passive balancing where resistors just burn off charge from the high cells as heat with a paltry 30-70mA.
Whoops. There i go using the word 'all'. :rolleyes:

Thanks for the clarification!
 
the cells I will be charging won't be grounded.

Why would that matter?

I already have the 48 volt version and was able to charge 12 volt batteries without a problem.

I didn't see that it had a secondary means of programming the output. Very nice. I have boatload of MW power supplies, just not these high end ones.
 
Why would that matter?
You're talking AC side and he's thinking DC side.

But as an aside, or another side..? This and i think most (i didnt say all this time!!) other MW say input xxx AC volts and xxx DC volts where the DC volts is just a rectified version of the AC volts, basically saying if you supply pre-rectified mains the input will sort of 'ignore' the onboard rectifier, and i get that but.. would simply hooking putting your split phase input through an external rectifier bypass the issue you mentioned? I am having a brain fart trying to figure that one out myself without going home and looking at my broken MW ps board i keep around just for visually trying to understand the process of what it does. I.e. i am being impatient. ?

I do know you can buy some pretty huge full bridge rectifiers (150a, 200a) for a whopping $15. I think i once bought a whole bag of those little square ones for like $10 before i even knew what they did.
 
It totally depends on your access to the actual cell-level terminals. I googled 'tubular fla' real quick and i'm still not sure yet how hard that would be for you.

Can you post a pic of one of your batteries?


This is exactly what all lithium battery BMS's do during 'balancing', although more specifically it discharges the highest cell into the lowest cell. But with lithium batteries cell level terminals are 'easy' in comparison to FLA, because unless you're looking at a 2.1V single cell 'battery' the cell level connections are buried inside a melted-shut 'water tank' and unless you're going to go in there and hook up 'laparoscopically' with tiny bendy robot arms through the cell vent cap, it's generally not easy to hook to the cell-level terminals.

Unless im missing something...?
here is picture of my batteries. Thanks
 

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Ok, something like that you have no access to cell-level terminals if it's a sealed up case that you can't just take the lid off of.

If that's the case all you can do non-invasively is an 'equalization' charge where you basically overcharge the rest of the cells in order to bring up the ones that are weak. Depending on how it's done it is somewhere between mildly and severely abusive to the cells which are already fine. But, it is also all you've got, unless you get into some weirder/riskier options. It would be the best option for most people, making the best of a bad situation using only the tools/equipment/knowledge which is already in place.

Battery manufacturer should give guidance on how to do the equalization charge. If their guidelines are followed it should be the case that what you gain by bringing the low cell back into balance, is a lot more than you lose by mildly abusing the rest of your cells. But, if the balance issue quickly reappears and a small number of equalization attempts fails to 'cure' the issue, you are stuck with a 'bad' battery because of one bad cell. And that is the downside of a sealed battery made up of multiple individual cells. One bad apple CAN ruin the bunch.

That is part of why when assembling a large-capacity stationary battery storage array, it's preferable to use a smaller number of individually-packaged cells of very high capacity, vs using a large number of smaller capacity cells which are sealed up in boxes of 6 (12v nominal = 6 cells in series for lead-acid). So for example if you look at Rolls batteries you can buy very large single cells of 2v, smaller 3-cell batteries of 6v, or even smaller 6-cell batteries which are 12v. Using the 12v batteries would minimize the external connections you need to create and maintain, but using the 2v 'batteries' (really just a cell) would maximize your serviceability and make you able to easily balance charge individual cells, or replace bad cells without throwing the rest of the baby out with the bathwater. :ROFLMAO: But yeah, rarely done to make a large storage bank out of individual cells in the lead-acid world, at least for home use. Possible but rare. A lot more likely in the lifepo4 world because those cells aren't flooded with liquid electrolyte so the logistics of making things out of single cells are a lot less onerous without all the liquid issues.
 
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