Assembly ProcessLithium Battery PairingPrecautions For Lithium Batteries in Series and ParallelLithium Batteries of Different Voltages in SeriesLithium Batteries of Different Capacities Are Connected in ParallelLithium Battery Charging in Series and ParallelIf different capacities or old and new lithium batteries are mixed together, there may be leakage, zero voltage and other phenomena.This is due to the difference in capacity during the charging process. Some batteries are overcharged when charging, and some batteries are not fully charged. When discharging, there are high-capacity batteries that ar...See more on bravabatteries that18650calc.dk
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All consumer battery packs will have a BMS that has a cutoff somewhere above 2.5v. Due to the non-linear discharge curves you get very little energy going