Marcus Reddish wrote:
Am I crazy or could bottom balancing be done at 3V with all the cells in parallel?
The voltage versus state-of-charge for LiFe lithiums is just about dead flat from 20% to 80% state of charge. Around 3.1v, voltage is essentially worthless as a state-of-charge indicator. The voltage changes more due to temperature, internal resistance, age, quality control, and other random variations.
3v is so close to this that there is still likely to be a large spread in possible SOC. It might be 10% or 30% SOC. Bottom balancing at 3.0v probably won't be very reliable.
People use a lower voltage (like 2.5v or 2.75v) because you can be pretty sure of the SOC (i.e. it's 0%).
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