Yikes, did I mess up with my battery purchase (commercial vs. deep cycle)

Got a used E825 with two year old dead (NAPA) batteries. Called the local store and got a small discount because of the age, so I went ahead and pulled the trigger. When I got there I noticed that they were “Commercial” group 31 and not deep cycle. After seeing this I called the local Gem dealer and was told that commercial batteries will be fine in this application.

Batteries in question:

My question is this: Did I just mess up and buy the incorrect batteries?

Thank you for the input.

Don’t know the answer to your question, but I was curious if you remember which NAPA batteries that only made it 2 years were in there before?

I’m looking at replacing the old Trojan T1275’s in an e825 and was considering the NAPA GC12

Would rather not make a $1200 mistake if they aren’t going to last.


I wouldn’t worry about the brand/model in this case. The issue wasn’t with the batteries themselves, it was with the previous owners treatment of the batteries. The car came out of a municipal fleet and they let the batteries sit, unattended, for a year or more. The constant state of discharge killed them.

I looked at the batteries you are considering and think that they might be a bit too tall for this application- not sure that the battery hold down system will work with them. I believe you want to be looking at Group 31 size instead of GC12. Maybe a more experienced member will weigh in on this.


Thanks Paul. That makes sense. Pretty much the same story as the e825 that I just picked up.

Interesting point on the height, I did notice the 1/4" difference, but didn’t think it would interfere. I’ll have to double check.

I was under the impression, possibly due to being given incorrect information, that the GC12 was the Deka counterpart (re-branded for NAPA) to the Trojan T1275 - maybe someone with more experience can comment. If I could find the Trojan’s around here, I’d get them since the price is the same. It would certainly be simpler.

Regarding the height, you’re right. I was comparing those to the batteries I purchased (which is looking to be incorrect for the car/application). I did’t have a frame of reference for the correct battery.