Thread: Auxiliary battery charging

Hi JX and yes a 10 amp charge circuit is way too low a current source for charging an auxiliary battery.

Depending on the size and type of auxiliary battery, it could try to draw as much as 100 amps, when decent sized cable is used.

Because the ?wiring? used in most power sockets is so small, the current draw of even a moderately discharged battery would would cause a fair bit of voltage drop but would still blow the fuse for that circuit.

There are a number of small DC/DC devices available that could charge the battery without overloading the circuit and blowing the fuse, but if your battery was a large one, say 100Ah, and was in a low state, these little DC/DC devices would take anything from 15 to 20 hours of constant driving before the battery was fully charged.