Lithium LiFeP04 Batteries

About

Lithium changed what an auxiliary bank can do. LiFePO4 from 50Ah to 400Ah in 12V, 24V and 48V, including slimline cases that fit under a seat and IP67 chassis-mount units built to live under a tray. Bluetooth models report state of charge and cell health to a phone. The usable capacity is the argument, not the headline rating. Lithium gives you most of its rated amp-hours rather than half, holds voltage until it is nearly empty, and takes a fast charge without complaint, so a 100Ah lithium generally outruns a 200Ah AGM in practice. It needs a compatible DC-DC charger, which is the part people forget to budget for.