Dual Batteries

[Wake]

When I ordered my vehicle I paid for the second battery. Can anyone help me with these questions
1. When I look at the electrical information on the screen and it gives me a battery charge percentage. Is this info only relating to the main battery?
2. If I attach a battery charger to the second battery will it only charge the second battery or will it also flow through to the main battery so both batteries will end up being fully charged
Many thanks

 

[TheDocAUS]

1. The two batteries are not isolated from each other, but the % is the main battery. You install a cheap BLE battery monitor on each battery of you want individual information.

2. Not the best way to do it. It will charge the aux battery and some equalization will take place between the two batteries.

In my setup, I mated a CTEK250SE with the 120S. Then added a rooftop solar panel. That setup will charge both batteries. This thread shows the evidence. The graphs are from the BLE battery monitor mentioned in point 1.

 

[Wake]

Thanks Michael I have now got a full primary battery and transferred my charger over to the primary.
Thanks again