Blue Sea Systems 7650 Add-A-Battery Kit

Hello, how is everyone doing? I just installed the Blue Sea Systems 7650. I followed the manual precisely for the installation. After finishing, I left the boat unattended for some hours. The boat was off but in the 'on' position, and I noticed that the engine battery was completely drained, but not the secondary battery I installed for my sound system. I've double-checked the manual, and everything seems correct. My question is, why did the main battery drain completely and not draw power from the secondary battery? I'm confused. When I'm out on the water with the boat off and want to use only the secondary battery for my sound system, should I leave it in the 'on' or 'combine' position? Some people suggest leaving it in the 'off' position, but that doesn't make sense to me. That's why I'm asking if anyone can help me with this issue.

 

What level of draw was on the starting battery? The acr is essentially a check valve, it will kick in when the starting battery gets inrush from the alternator and kick out when the voltage drops (can't remember off the top of my head the exact voltages) The idea is you preserve staring battery while draining the auxiliary battery.

If there was residual draw on the starting battery that was capable of killing the starting battery it would not allow the auxiliary batter to back flow the staring battery. Memory is hazy, does the kit come with a dual circuit battery selector? The only way to have the auxiliary battery drain back to the starter battery would be the combine setting which essentially un does the check valve/diode of the acr and both batteries would then be equally dead.

 

Started battery was almost empty and house battery was full

 

I meant, what load was on the starting battery that caused it to drain? I.e. was there any load aside from the acr and the auxiliary battery?

Trying to isolate possible drains, it's possible the acr drained it but it's best to eliminate variables first.

 

Contact Blue Seas tech support for your best info.