Was going to install a battery isolator but then saw some info on these voltage sensing relay's. Has anyone had any experience with them? They seem a little more compact as well.

http://www.bepmarine.com/en/710-140a

I used the Blue Sea's ACR on my last boat. Worked very well, and is well worth the minimal investment. I haven't installed on new boat yet, as I don't know where I'd install house battery yet.

Google Blue Seas Add A Battery Kit.

+1 on the Blue Seas ACR's. Have two of them on my boat and they work very well.

I just installed one of the Blue sea ones as well.. worked perfect my first trip out..

This past weekend though, it wouldn't turn on. Stereo went dead while cruising around.. Had to move the battery switch to "combine"..
Haven't had a chance to look and see what happened yet...

It won't combine batteries to charge both unless charging voltage is over 13.6 volts. I'd check alternator output.

http://assets.bluesea.com/files/reso.../ChooseACR.pdf

It's good.. Alternator is actually connected directly TO the Blue Sea switch.. I'm thinking maybe the little ground wire came off... Got some airtime over the weekend..

Winner.... put a voltmeter on it again.. Alternator is putting out 13.4 volts...


It's a 1 wire GM alternator.. All worked fine two weeks ago.. NOW only have 13.4 volts out of it.. (even at 5500 rpm).... wtf...

A good alternator should maintain battery voltage between 13.9 and 14.8 volts. Might want to go ahead and rebuild it before if fails completely.