I have a Guest 2 bank battery charger that i no longer use off of one of my boats, i went to a 24 volt trolling motor and had to go with a 3 bank charger.

So my question is can i take the 2 bank battery charger and use both of the 12 volt leads on one 12 volt battery on my small boat, the charger is 2 bank 10 amp on each bank, i noticed when i used only one of the banks the lights on the charger would not work right, and will this charge the battery at 20 amp rate.

Thank in advance
Speck