Thanks again for the feedback. I’m on a time crunch right now. Trying to get the board done in the next seven days. I’ll be using the board daily for the following week (if I can get it done in time). After that, I’ll think about how I might be able to change things so I can check cell voltage. Maybe just go back and add leads.
finally someone who also did a nice soldering job, i recently replaced my powertool batteries and also soldered them and i only put the iron around 1-2 secons max…barely any heat on the surface…dunno why people are so against it.
By the way, if one cell is dead (or dying), how could the pack show the correct voltage? If a single battery is dead, the pack will read only 45.87 volts, whereas it should read 50.4 volts (@ 4.17 volts per battery). Point being, if I charge a pack fully, then test it, if it doesn’t show 50.4 volts, then I know I have a problem battery. What am I missing?
Well initially you said you weren’t charging them full. Another issue with a bad cell is it may read fully charged but the capacity is no where near the other batteries in the pack.
If a 12s pack has a bad cell and you charge it up to 50V the other cells will typically be overcharged and 1 will be under. Not to mention you’d want to charge the 12s packs individually, as if a single pack of 12s1p cells hits 50.4V all packs will stop charging. While building cells like this can be handy there is a reason why every battery ever pretty much runs the p groups before the s groups.
I believe your charger will keep charging until it gets the correct voltage, so I will over charge the rest of the good cells untill it reaches 50.4V. Someone feel free to correct me on that.
Okay. Well, like I said, after this trip, I’ll think about taking a different approach to the pack. For the moment, I’m going to plow through and get the board done.