Battery chargers and Switches

[Redfish Ron]

I see a lot of on-board battery charging systems advertised and dual battery isolation switches- Talk to me about all this with some straight talk- are they worth it?  What are the disadvantages (if any) and advantages- back in the day when I had a boat we just had the battery (ies) hard wired in and the motor charged them when running...if they are so great...which brand and what specs do I need in my 170 running a 2 stroke 75 hp 1998 Yamaha? I bought an Optima 30 series AGM Battery at Bass Pro for my boat- Still in my workshop sitting on my wood workbench-

[RickK]

The isolators stop a bad battery from taking down a good battery.  The engine will still charge both batteries.

[BradleyD]

Are you talking about a "batttery isolator" or just an "isolation switch"? A battery isloator is a good idea if you have a two battery setup where you have a deep cycle "house" battery for electronics, etc. and a regular high cca starting battery for your motor. Just as Rick said...both get charged but if you blast your radio too long or run the trolling motor all day and drain the house battery its not going to effect starting your motor. The isolation switch just kills the power, or selects a certain battery depending on the type switch. If you're going to be running the single optima then just a switch would suffice. Hope this helps.

[seabob4]

Do some reading on Blue Seas ACR and BEP's VSR, those are the 2 most popular combiner/isolators.  

As far as battery switches go, I use Blue Seas switches almost exclusively.  You can read about reasonings and installation here, just ignore the fact that they call out a Perko switch.  I don't use them, the contacts tend to corrode inside (I know, I've cut 2 failed ones apart to see WHY they failed!)...