View Single Post
Old 11-10-2022, 01:25 AM   #9
Pat911
Gone Wild
Club Car
 
Join Date: Dec 2020
Location: Melbourne, Australia
Posts: 1,919
Default Re: Lithium batter voltages different in parallel.

Thin wire on alligator clips, no wonder your cells are all over the place. As Volt_Ampare said, your cells are WAY out of balance now and that will have to be fixed prior to rebuilding your pack.

You really need to create a very low resistance connection between the cells to balance them as a pack. If you cannot do that, get a laboratory style power supply of at least 10 amps as already suggested and charge each one up to 3.65v. Keep charging until the current drops to 1% of the original charge current, or 100mA. Repeat 16 times. That will ensure each cell is at 100% capacity. Use a large gauge cable between the charger and the cell. Do not use thin cable with inadequate alligator clips.

If you had one sagging cell, it is most likely a bad connection between the cells. Are you using copper or aluminium bus bars to connect the cells when they're in the cart or wire links? Are the bolts torqued down to spec? Are the balance leads connected to the positive of each cell? You may have connected to the negative of the next cell with would be OK for low currents but would give a lower cell voltage when drawing higher currents due to the increased resistance due to the link.

Anyhow, first thing to do now is to balance the cells again. Do you have access to a power supply?
Pat911 is offline   Reply With Quote