Why Use 48v nor 12v Battery Backup in EV System?
this is official answer:
The 12V voltage system has basically reached the power output limit after introducing the start stop mechanism. If the light mixing system is introduced under 12V voltage, the power demand is about 10kW~15kW. Under such a voltage, the output current of the battery is as high as 1000A, which is obviously not feasible.
this is very easy to understand. to drive a EV system, you can count how much power to drive the EV car. voltage * amper = power. therefore, using much higher voltage will give a less demand in ampers output. so after many test, scientist forward 48v system is the best to drive EV.
currently, we have 48v 200Ah lithium ion battery for EV car.