I'm not well versed on batteries, so I figured someone here could clear up my confusion.
It seems the Optima 34 batteries only fit if you cut the battery box a little. Will the Optima 25 batteries work instead of the 34?

Here's a link to the 25 Power wise, its 720 CCA, Reserve is 90 min.

Here's a link to the red top, but the posts look to be in the wrong position for our hummers: 800 CCA, 100 min reserve

Everything is stock on the vehicle, so that's why I'm looking at red top vs yellow top. If there's a solid reason to buy the yellow, I'd go for it.

 

some of us junked out the batt box and made a plate for 2 batteries. handy only when a goof up kills the main batt.
i had that recently and its nice to just jump a short wire over and start up and go.

any batt will do in the h3, i once used a small lawn tractor batt,230 amp i think. it started and worked fine so it could be the 2nd batt.

only if you run those thump/thump 1000 watt noise makers would you ever need extra juice.
the generator is ok for heavy loads. i once put an ext 65 amp load on for a while with no trouble.

so batts are not a problem ,,,nice to have a 2nd for emergency starts tho..

any small batt will do fine.

 

Not to sound like a jerk, but a second battery that sits there unused will simply die. Even after a month, the battery can start to have trouble. Unless these dry batteries have some properties I'm not familiar with, I'd rather just carry a portable jump starter with me.

I just need one. I'll probably just go with a red or yellow top Optima & negate the tray. That's a good idea. Thanks.

 

yeah, the 2nd batt is always being charged naturally but its isolated so it never gets drained.
you gotta know what youre doing.

use a diode to charge it,,,no backfeed.
it works great.

 

I see! I read that as the 2nd battery would be just sitting there. That makes sense now. That's a good idea.

I'd have to do some reading about it before setting that loop up.

Thanks for the info. I am not sure if I'll go that route (cost & everything), but it's something I might do in the future & it's good info to keep in my back pocket.

 

My dual Optima 35 set up. I have an IBS dual battery monitor which keeps both batteries charged but only drains off one to start the truck. I can jump start myself from the second battery with just a push of a button.

 

to fit the yellow top you just have to cut the top of the battery box. I used a dremel. here is how mine looks