Can I charge my new Marine batteries in my 2000 Gem e825?

I once saw a thread about this but I can’t find it anymore. Temporarily running 6x Group 31 marine batteries and was wondering if I can just plug her in to charge, or if there is something new I need to do. Any help is much appreciated, I don’t want to fry my new toy.

Depends what charger is installed in your GEM. Some have multiple charge profiles and you would want to verify that it is set to the proper flooded lead acid profile for your batteries.

Stock location for the charger is under the dash. If you have the original Schott charger (silver ribbed box) then all it can do is FLAs, so go for it.

If you have something else, should probably check it.

Oh, and the master disconnect switch under the seat must be set to ON.

Thank you for the reply! I for sure have the silver charger, not the yellow one.

Final question, will it stop charging on its own when fully recharged, or do I need to monitor the charging time manually?

Thank you again, this forum has saved me so much time and $$.

Those weren’t the only two that GEM used and then there were some aftermarket ones, but yeah, sounds like you have the original Schott charger. It’s completely obsolete technologically but so long as it works and as long as you have lead-acid batteries (ones with caps that you can add water to), you’re fine. Run it until it croaks or you change battery technology. Don’t ever put sealed gel batteries on it, it’ll murder them within a few months. It might work with sealed AGMs, but I wouldn’t risk it.

It is supposed to shut itself automatically. Note, it does not have an auto restart or trickle charge / maintenance charge function, so if you are leaving the cart for a long period without use, you will need to unplug and re-plug the charger or get a 15amp heavy duty 7-day electrical outlet timer and set it to come on for like 8 hours once a week.

So based on your info it looks like the batteries they recommended me may be the wrong kind. Here is what I’m running. They are not the kind that require water. How bad are these for the gem?

What happens when these batteries are plugged in? They say they can be charged up to 2AMPS which I think is what my charger puts out. This is all new science to me so thanks for the education. Next time I’m getting Trojans, I was just hoping to get 2-3 years out of these

Those are fine, they are FLAs (Flooded Lead Acid). The access to the filling hole for each cell is under the 8-sided caps. Just pop them off with a flat head screwdriver, there are 3 cells under each cap.

I have those same 31DCMJ batteries in my '02. You should have no problems getting 3 years out of them so long as you take care of them (water when needed, don’t run down past 40%).

Trojan 31XHS and the even larger T-1275 are wonderful batteries. The gold standard for batteries in that size range. They weigh almost 50% more than other batteries in their respective size groups, that should tell you something about how much lead is in them. But, they are bloody expensive. $1300 or thereabouts for a set of six. For that coin, there are so many other options.

That makes me feel so much better. I am glad you are having success running a similar setup.

When you say don’t go past 40% are you referring to the battery meter? With your ‘02 about how many miles do you get on a full charge? How often do you check the water levels? We will be wanting to use this daily so it will get a lot of use. I want to make sure I get the most out of them.

One last question since you seem to know a lot about these. When I first turn the key over some numbers come up in sequence. The first says “70” and the second “1330” is the 1330 mileage and the 70 ride hours? What is considered low mileage for these?

Thank you once again, I am feeling better and better about this project.

Yeah, as you are driving, the display will periodically switch between your speed and the SOC (state of charge) of the batteries. Don’t go below 40% on the SOC or you risk damage to the battery cells.

15-20 miles per charge is a reasonable expectation. It of course will vary based on your terrain and driving habits. Eventually the batteries will have aged and you’ll start seeing range closer to 10. Keep your tires at 35PSI, lower pressures will create additional friction and detract from your range. Make sure your brakes are releasing fully, a single dragging drum could take your range from 20 to 8 instantly. I’ve had this happen to me.

Depends where you live and the weather but checking water levels every 4-6 weeks is a reasonable practice. The batteries should be equalized every 10 charge cycles or so. Equalization is where you go to a higher finish voltage on the charger so that any lagging cells / batteries can catch up (typically it’s the ones in the center of the pack). That Schott charger doesn’t have a built in equalize function, so you accomplish this by running back to back charge cycles with no driving of the vehicle between.

The 02-04 has a different motor controller (the T2) than the 99-01 (T1), although they are very similar. On key-on with the T2 the display flashes the SOC then goes to the speedo which will be zeros, On key off, the display will flash 4 digits, then another 4 digits. That’s the vehicle mileage in reverse order. The first 4 are the 0-1000 places, the second 4 are 10,000-1,000,000. For example, mine might flash 0364 then 0001. This would indicate that I have 10,364 miles on the vehicle. I think it might also flash 8888 as a segment check at some point - I don’t really pay that much attention to it myself.

The T1 might display differently but I am unsure as I’ve never worked on one. If it is as you suspect, 70 hours / 1330 miles is certainly reasonable (average 19mph).

I’m sure Rodney knows the answer to that question, he’s the guru. Pretty sure he knows more about these than the guys who designed them… @Old_Houseboater

I would say that 1300 miles is on the low end for a 21 year old cart.

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70 is the state of charge 1300 is the miles. make sure your charger is set up for the batteries you have installed. If you have the silver charger its probably set up for flooded. I drive my cart a lot and I check levels monthly. I dont my charge get low, I plug in every night.


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Thank you so much guys, I can’t thank you enough of taking the time on another newbie lol.