Ok, sounds good. Found these this morning. At a $1 a piece I may try them. What do you think?
I like it. Iāll check specs later. Busy Day today!
Alibaba is wholesale. Prices are only teasers. Look for them on aliexpress or ebay for real pricing.
I donāt understand the circuit. Two leds is weird. No good if always on.
Closest I can find. Spacing on the lugs may be off, we need 61mm.
Made some good progress yesterday. I found out that if you set the charger to 5a, you can balance charge the cells with the BMS. I did have one that wouldnāt get over 3.3v no matter how hard I tried, so I swapped that one out with one of your new ones, thank you!
I set the charger to 2.5a, 3.5v. When I noticed a cell climbing higher than others I attached an old Gem Headlight with alligator clips to the cell to slow its charge. I chased a few cells all day with two lights and finally go the pack to 98v. I left it on EQ over night and I am down to 0.034v difference in cells. The one I swapped was still a bit low, Im working on that now. Hopefully this is it, fingers crossed.
So moving forward, this 25a LifePo4 BMS protection board. If I was to charge at 20a, would these bleed off energy in over cells that climb higher than others to balance faster than the BMS? Is that how it works? Sorry if that sounds like a stupid question, but Im thinking it would work the same as my headlight trick, just able to handle more amps.
No, itās a bms with very low balance current. Not listed.
These are what I use:
1 amp shunt balance with led.
When all leds come on together, battery is full and top balanced.
When several led come on, stop charge untill they bleed down.
Repeat until all light up.
Should only have to do this once.
Morning Dave, do you have one of those boards? I finally got a chance to put some miles on the car yesterday and only got 7 before I got a low voltage alarm. Took it back to charge and the cells were all over the place.
I only have a 16s board. It may not help in this case. I wonder if some cells have been damaged from over charging or under charging.
It shouldnāt be this hard. Michael just built another Gem, dropped them in and drove 20 miles with no bms.
If I knew cells were ok, Iād suggest bottom balancing again.
There is no easy way to test them. They may need to be charged individually, then see how many miles you can get before a cell goes under 3v.
I would be glad to test them and balance them again, but would need them here.
Sorry for the trouble, I donāt know the issue.
On the last picture, is the 59ah correct? You put 59ah into the pack?
Michael is using a little V/A meter that letās him track ah he is using. The bms will do it also, but the load must be run through it, and you canāt pull more than 300a without tripping. I am using it on my truck.
Another thought. The bms may turn the charger off at 60ah. That would be a simple problem.
Just turn it up to 75ah or so. Reset ah to 0 or guesstimate of remaining capacity.
Iāve never checked to see if ah turns off charging, but it might.
You could also charge directly to the battery if cells are balanced or yo monitor them.
Do you mean cells are all over, after your drive? That would be normal. Canāt be balanced at both ends.
They should come inline when bringing them back up to 3.347.
The charger is tripping with overcurrent at 3.65v, not over 60ah. I have been chasing the high cells with a headlight and some alligator clips to limit current going to them while charging, hoping that the others catch up. I was able to charge once where the charger turned itself off and didnāt read connection break.
While driving there is a very large voltage sag under acceleration and most if not all cells fall below 3v. After 7 miles there was about a .1v difference across the 28 cells.
Iām not seeing the light at the end of the tunnel.
It may be best to send them back. It is near impossible that they could all be bad. I canāt figure it out.
At least, I might learn something.
As a last resort, you could top each cell off with a single cell charger. If you do, DO NOT try to voltage balance them. Turn balance off. When they are full they are full, regardless of voltage. If you canāt get 15 easy miles out of them, the car is drawing too much current or the batteries have lost capacity.
My plan at this point is to order a 7pin jst connector with leads, a bunch of alligator clips and with my imax b6 to balance charge 6 at a time. Iāll disconnect everything and just do groups of 6 until the are topped off and go from there. Sound like a plan?
I think you need to do each cell at this point. I have a bunch of single cell 10a chargers, that I can let you use.
There is something simple going on, but I donāt know what it is, and I can tell itās frustrating for you.
Iām glad to take them back if your ready to try something else.
Iām hoping Michael sees something Iām missing.
Hey Dave, long time no talk hope you are doing good. Been incredibly busy here, Im in my 4 months of hell for my business, but Ive been running the Gem around town having a great time when I can, the kids absolutely love it. I had some time yesterday and swapped out a battery that seemed to always drop out fast, and now Im busy top charging again. I was looking through this old post and forgot about these stand alone balance boards. Did you ever get anywhere with them?
No, a shame. Must be hundreds of them. All i need to do is connect one. 
I have the matching bmsās also.
Ill be a test subject, send me a bunchā¦
Iāll test one tomorrow, so not to waste your time.
Check with @LithiumGods for balancing. He has it down.
Iām still agin it myself. 
Iām bought the balance charger he suggested and it works like a champ. The weather has just been so bad I havenāt really had a chance to put any miles on the batteries. I knew that #3 was having issues so I swapped it and am now top balancing with the charger. Just takes a lot of timeā¦
Thanks for the push. Couldnāt wait til morning.
They work great. Led balance indicator. 500ma current.
Quick check seem about 3.6v start. .5 amp at 3.7
Bright led.