I am in the process of doing a second as an accy batt. I dont plan to use for cranking, just air comp, lights etc. My second is a GRP27 deep cycle. I am not sure yet what I will be doing for charging system yet. Thinking of the KISS. A constant duty solenoid with ignition switch on off switch, and wired to vehicle charging system. Fused of course.Thoughts? I have heard where isolators lower voltage and don't like that idea.

I stopped by today to ask the same question.

I heard the once leading Optima has declined in quality (manufacturing moved to Mexico, apparently).

I am referring to one start and one house battery .

Dan , are you running a single Optima Yellow Top battery ?

Yeah, I have not had any real issues with my single Optima, but I guess it would be nice to not drain it when sitting for multiple days.

If I were to do it over, I'd do one large battery instead of duals. Currently have dual 24s.

Thanks Dan for the fast response . Currently reading the how to article . I have a Land Rover LR3 and it comes with 2 battery boxes because of them building both left and right hand steering vehicles . Should make the job a lot easier . I think I will probably go with an AGM battery and use a Magnum Smart Battery Combiner ME-SBC . Fisheries Supply in Seattle sells the Magnum line and I have used their inverters in boating applications. Thanks again , Peter Bolay

Hi Peter,

Here is a pretty simple step by step for a dual battery install. I guess it depends on how much space you have to work with, personal preferences on battery makes and what your load will be. I am running a single Optima Yellow Top for all my accessories, but I know that soon, I will be entering the dual battery realm. Let us know what you are planning!

https://static1.squarespace.com/static/549ed406e4b031a7658c3dc1/t/5a81f3bc652dea024c4d4705/1518466167894/Dual%20Battery%20Setup%20-%20Ivan%20Bustor.pdf