Onboard Charger Question

[Ray]

There are chargers too. It all depends on the chargers amp capacity.
You can get up to 100 amp output, but that is not what a center console fishing boat needs.
Most are 5 + 5 or 10 + 10.
I have a 20 amp smart charger on my big boat. It puts out up to 20 amps total. It is connected to 2 different 12 vdc batteries. It will give what ever each one needs, but up to a total of 20 amps. If one needs 2 amps and the other can get up to 18 amps.
My trolling motor charger is the 5 + 5 amp type. It can give up to 5 amps for each 12 volt battery, or 10 amps on a 24 volt system.

I have used my trolling motor 2 straight days, hard, and it will charge up completely overnight.