Originally Posted by sailalibi
Anyone see a problem with charging
2 12v batteries
(a start battery and a windlass battery) in parallel with a single
Tough to make out the actual question but an ACR is designed to charge one battery from another battery. It is not designed to charge two banks where neither bank has a charge source charging it.
If your start battery
has a charging source, then you can charge the windlass battery with the ACR.
If neither battery has a charging source then you'll need an ACR for each battery from which ever bank receives the charging, most likely the house bank
The article below may help you understand how an ACR works:
Making Sense of Automatic Charging Relays