Battery Switches

I was reading old threads trying to figure out my Autowake Surf settings and I came across a battery switch thread that got me thinking. I have seen lots of discussion on this forum over the years about battery switches... put it on 1 or 2 or ALL... but I have never really shared my solution for it, which I think is the best way to go. I did this on my 2001 Outback years ago, and when I bought my new Max, I did the same thing. I actually ordered my Max without the dual battery option (or charger) so I could make my own setup. Here is what I did...

I wanted to use a Blue Sea Systems Add-A-Battery kit, but they didn't have a kit with the parts I needed, so I just bought the parts. The kit with the "Mini" switch only comes with a 65 amp ACR, which is not large enough for the alternator on these boats. First I swapped the OEM battery switch with this one:

https://www.bluesea.com/products/601...y_Switch_-_Red

Then I installed this Automatic Charging Relay (ACR):

https://www.bluesea.com/products/761...12_24V_DC_120A

For those of you that don't know, the ACR automatically combines the two batteries when the engine is running so the alternator is charging both batteries. However, when the engine is off, the ACR isolates the two batteries (or banks) from each other. So you can play your stereo without affecting your starting battery. With this setup, you never have to think about what position the battery switch is in... just turn it on and go. If there is an emergency low starting battery situation, you can still combine the batteries manual with the switch if you need to.

Here is the switch, fits in the factory spot.
Attachment 30936

The ACR.
Attachment 30937

Didn't quite fit on my amp board, but my charger did.
Attachment 30938

I hope this info might help some folks simplify their battery switching lives!