With RC chargers and balancers, a pack is considered "grossly" out of balance if the cell voltage difference between the lowest and highest is above 0.
What if there is a voltage difference in a battery pack?
Therefore, you should pay attention to the brand from which you are purchasing your batteries. If there is a gap in the voltage of the battery pack, you can correct it with additional equipment, such as with a BMS, balance charging, etc. Stay tuned for Part 2 of voltage difference: How to prevent voltage difference.
If the voltage is below 2V, the internal structure of lithium battery will be damaged, and the battery life will be affected. Root cause 1: High self-discharge, which causes low voltage. Solution: Charge the bare lithium battery directly using the charger with over-voltage protection, but do not use universal charge. It could be quite dangerous.
Generally, SDR is quite low for Li-based batteries but the output impedance may differ by 10%. what is appropriate voltage difference between cells? What voltage difference could indicate that some cells are not as good as others?
Root cause 1: High self-discharge, which causes low voltage. Solution: Charge the bare lithium battery directly using the charger with over-voltage protection, but do not use universal charge. It could be quite dangerous. Root cause 2: Uneven current.
How does voltage difference affect battery performance?
For battery packs, the voltage difference between individual cells is one of the main indicators of consistency. The smaller the voltage difference, the better the consistency of the cells and the better the discharge performance of the battery pack.
A 12v Battery Pack was at 0V and wouldn't take a charge. Manufacturer Miady recommended starting up the sleeping BMS with a 9-volt battery across the terminals. I tried this -- it worked! Battery read just over 10V on voltmeter. Immediately connected to charger.