A 24 volt , or 48 volt battery system, comprising 2 or 4 *12 volt batteries , charges based on the total battery voltage . this can mean individual batteries within the series can be at different voltages , leading to imbalance. this can lead to some batteries been overcharged , and others been undercharged . This seems to be quite a big problem with lithium batteries , with individual battery BMS cutting in and out , leading to a largeimbalance.
A battery equalizer will even out these voltages , which should ensure all batteries receive a more equal charge / discharge cycle.
One unit is required for a 24 volt system ,3for a 48 volt system. 5 amp max current.