Charger not set for AGM

Sorry for the constant flood of questions…I’m still trying to figure out what is best for my GEM. Found out today that, after the micro upgrade on my Zivan, it can be set for either flooded batteries or GEL batteries, but if I want to be able to use AGM’s, I have to send the charger in once more for a different upgrade. Since I also found out that the new batteries that the owner installed are deep cycle 24’s, I guess I have a decision to make sometime in the future. I guess I’ll go with GEL batteries if I can afford them. Is size 31 the same as 8272? I just want to make sure that I get the right ones! Thanks for the help.

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Thanks for such a thorough response! Very helpful! I’ve done a quick search, and can’t find a Deka dealer near here. So, so add to my barrage of battery questions…will any size 31 gel battery do the job? I can find Optima gel batteries locally (those funny looking batteries), and a couple of other gels. Will any of these work, as long as they are size 31?

While I largely agree w/ GTMO-GEM regarding batteries, I’ve never seen any empirical evidence or cogent argument regarding the life of AGM/GEL batteries vs FLA to justify the additional expense.

I do know that AGM/GEL technology is more sensitive to “overcharging” and unless carefully addressed by the charging algorithm the stack can become “unbalanced” over time. Overcharging a stack of FLA, which are more tolerant, helps prevent this occurrence with that technology.

I’ve also heard that a stack of 9 x 8v cells gives better performance vs 6 x 12v cells but don’t understand why that might be. That Polaris/GEM switched to that configuration for the XD gives me some confidence that is the case however. I’ve never seen how the 9 batteries physically fit in the GEM so I don’t know what would be involved in retrofitting this configuration into an older GEM. Somehow you’d need to fit 9 cells in the space originally planned for 6 though I imagine each cell is smaller.

If I absolutely had my “druthers”, I’d go to LiFePO battery technology. Unfortunately the startup cost would be about 3 or more times the cost of FLA. OTOH, LiFePO supposedly will “last forever” (10+ years anyway) and give a much longer drive time in day-to-day use.

Napa 8272 is a group 31 size Gel battery & is made by East Penn which also makes Deka 8G31. Optima AGM batteries (blue, yellow, red) are made by Interstate.

You are absolutely correct! I just learned that the Optima batteries (shaped sort of like a six-pack) are AGM batteries, and my charger would need an additional upgrade to be able to work with them. I did receive my “micro upgraded” Zivan charger today, and re-installed it immediately. I had individually charged each battery over the weekend in preparation. Once installed and plugged in, the charger began to slowly blink red (no audible signals), which was the reason I sent it in for an upgrade in the first place. All of a sudden, the red blinking stopped, and it switched to yellow. I’m anxious to see if it charges completely to green. I’ll be leaving for several days, so I went and unplugged the charger. I turned on the key, and it read 100% charged, although the charging light had been yellow. I turned off the master switch, and will continue with this when I return. As stated earlier, I just realized that the “new” batteries that the previous owner installed are deep cycle FLA 24’s, and probably won’t do the trick. I’ll have to sit down and make a decision as to whether I want FLA 31’s or gel 31’s…

Not any group 31 battery will work. There are group 31 starting batteries that should not be used in the GEM (except in an emergency). Both types are quite common and we use both here at my work. NAPA 8272 is a group 31 GEL dual purpose deep cycle battery. By comparison, NAPA 7236 is a group 31 FLA starting battery and should not be used. I consistently get 4.5 to 5 years from the 8272 in GEMs that are driven daily.


Thanks, Daniel. Your advice is always so valuable, and to the point…you include information that others may take for granted. I hope to be able to install NAPA 8272 batteries at some point in the future. I’ll see how my upgraded charger does, and will proceed from there. Thanks, again.

Not sure why you’d turn off the master switch and unplug the charger when you leave. I think I’d leave it ON and the charger plugged in and the batteries charging. When you get back, they should be fully charged and the light should be green.

I’d love to hear from experienced FLA owners telling me to stop buying these overly expensive AGMs in preference to buying FLAs. [/quote]

I haven’t had my Trojan 30XSH FLA batteries long enough to tell for certain but my [U]expectation[/U] is that I’ll get at least 4 years of usage out of them assuming I keep them watered and charged and don’t abuse them by running them much below 50% SOC. Unless you’re getting substantially more than that from the AGM/GELs I’m not sure the economics make sense if they’re 2x more expensive. Miles wouldn’t be too meaningful since I can only drive the vehicle maybe 6 or 7 months of the year in this area of the country.

You’re right…I’ll plug the charger in before I leave! Please keep me posted on how your Trojan 30XSH FLA batteries are working!

OK, I’ll plug the charger in before I leave. I guess I was just afraid of getting the blinking red light again. Please keep me posted on how those Trojan 30XSH FLA batteries are working! Here’s one more question…If I purchase a cheap, small folding crane, can I use it to lift the batteries out of the cart? I’m a lady, not a man like most of you, and not only am I not as strong as y’all, but I hurt my back a couple of years ago, and simply cannot lift such heavy weight, especially having to bend over into the car to reach the batteries. I really enjoy working on things like this myself rather than have someone else do it for me. That way, I can keep learning about how these vehicles work. Hope this question is ok for the forum. You have all been so helpful so far, that I just thought I’d ask! Thanks

Be sure to turn the master switch ON when you plug in the charger. With it off, it won’t be “seeing” the batteries to charge them. Switch on and charger on is “normal”.

I’m not sure about a lift for the batteries. At least on my GEM, there’s a lot of twisting and turning to get the batteries out and back in due to space constraints, struts in the way, wiring to avoid, etc. You might want to hire a young kid and have him do the heavy lifting to get the batteries in/out under your supervision.

One tip: Make good note of the terminal orientation BEORE you pull the batteries out and be sure to get the terminal orientation correct when you set the batteries in place or you’ll have to pull them out and do it again!! And once is enough.

So far my Trojan batteries are working great. Previously I had 2 1/2 year old Interstate Marine deep cycle batteries which weren’t working worth a darn.

I replaced one Interestate when it failed catastrophically and shortly thereafter a second one failed and I decided to just replace them all with “matched” Trojan batteries (i.e. same manufacturing date). They were nearly $200/each so it wasn’t cheap but the batteries are the heart and soul of an EV and I firmly believe you should purchase the best batteries you can afford and treat them right (keep the watered and charged). So far I haven’t been disappointed.

Came home from my trip, and the GEM was 100% charged. Drove just about 2 miles, just to check things out. When I returned home, it was showing 67%! I’m guessing that the batteries will have to be replaced sooner than I thought. I’m leaning toward Trojan FLA’s…but haven’t completely decided, yet.

I also just installed the gam batteries but the interstate model. I had gotten the blinking red light so I checked voltage on all the batteries and the read 13.26 to 13.28. I checked the voltage while the batteries were disconnected from the other batteries. When reconnected batteries and fired up the charger it seemed to cycle correctly and I eventually got the green light. After driving it for a few days I plugged it back in and now I’m getting the red blinking light again. My charger has the gam setting selected on the dial so I’m lost now. Any ideas?

I eventually purchased the NAPA gel batteries. I still get the blinking read light when I plug it in, but found out that this simply means “charging”. It eventually goes to amber then to green!

When you wrote “gam batteries,” did you really mean AGM batteries? Just checking.

East Penn Deka and Exide batteries are probably among the best quality in the US. HOWEVER. Johnson Control bought Optima an they have quality control issues now. and I am 99% sure Napa batteries are also Johnson Control now. Federated auto parts stores sell federated batteries which are East Penn AGMs

Just for clarification. The Zivan NG1 charger will fully charge the batteries and then will shut off. In order to remain charged, the power must be cycled every few weeks. otherwise, the batteries will slowly discharge. Many use a “vacation timer” which will turn on the charger once a week.