Dual battery setup

[mister.freeze]

My ‘72 K5 currently has 2 yellow-top Optima batteries that are getting pretty tired. I previously had standard group 31 batteries and was happy with them. Then I lucked into these Optimas and have had them quite a while.

Of the 4 Optimas available, what combination would you use and why? I have 2 batteries because of lights and stereo demand and hopefully, someday, a winch. Or should I go back to the cheaper and more common big rig batteries? Thanks in advance.

[Mike C]

I am a big a fan of the Optima batteries but probably won’t be buying more as they are just too much $$$$. As they age out, I have been replacing them with Duracell AGM marine batteries from Sam’s. Current price is $125 each. I am NOT a fan of side terminal connections so my trucks have been re-wired with welding cable and copper lugs. I like the screw terminal connections on the tops of the batteries along with the standard top post.

[Sand Wrench]

I'm in the same boat, adding aux battery and winch to my K10. I was planning to use a deep cycle marine battery in the auxiliary position to run lights and chargers in my camper shell, but I'm concerned that a constant voltage charge from the vehicle electrical system would shorten the battery life. Anyone here have experience with deep cycle batteries?

[mister.freeze]

not a lot of responses. One reason I like the optimas is that they couldn't 'boil out' from constant charging like generic lead-acid batteries. The suggestion of AGM batteries is good, but I though optimas were AGM. The question at hand, though, is about the combination of battery types for best performance.

[hemi43]

Optimas are not as good as people think. I have one here (red top) less than a year old that wont keep a charge.
Using deep cycle batteries is not a good option either. They are designed to be slowly discharged then recharged and can handle constant 50% drops. This is the opposite of what you want in a truck/car battery. A car battery is designed to have a high load applied to it (starting) then recharged immediately.
Unfortunately, most batteries suck today so it's a luck of the draw if one will last 5 years or not.
If I had to have a dual battery setup for stereos and such, I would use one conventional battery for starting, then I would use a deep cycle for the accessories but I would isolate this battery so it doesn't get used for starting the truck. RVs use this type of isolator for that exact reason.

[BobbyK]

I installed a Hellroaring Battery Isolator in my 71 Blazer back in 2000.
Model # BIC-7300A
$189.90 back then but I bought the in-cab remote module as well.

New part # is BIC-95300A
https://www.hellroaring.com/products.php

I had a red and Yellow top Ultima batteries. Red was my starting and vehicle 12V POS supply and the yellow was a backup.
I have a Warn 9000 winch and wanted the 2nd battery for that.
It's still working well today.
The Optima's crapped out in about 3 years though.

I use it in conjunction with a remote starter solenoid.
Here's a pic.