Best charging plan for GEM wet cells?

GEM Forum
1

I have a 2002 GEM E825 … inherited it from my Dad, so I’m new to EVs. I just put in all new 12V wet cell batteries.

MY QUESTION: What’s the best way to charge these batteries to maximize their useful lifespan?

The GEM Quick Reference guide says for best performance “… WHENEVER POSSIBLE, RECHARGE THE BATTERIES—
NO MATTER WHAT STATE OF CHARGE IS INDICATED.”

To me this means always keep the GEM plugin when not in use. Is this the best way to maximize battery life? Since my GEM is used only a few times a week, this means that the cart could be plugged in for a few days continuously without use. Is this good for the battery?

It’s my understanding that wet cells only have a finite number of recharge cycles in their life. If I plug it after EVERY use and keep it plugged in until the next use, won’t I be using up these recharges prematurely?

I could just plug it in when the charge drops to a certain level (50%???). This would reduce the number of recharges and extend the battery life … correct?

Also, will keeping it constantly plugged in keep the batteries “warm” meaning that I’ll have to add water more frequently? (I live in the San Francisco Bay Area, so we rarely get freezing weather.)

I know one can use the master disconnect switch to reduce battery drain, but I don’t want to do this. It’s too much of a hassle to remove the seat and remember to keep turning the switch on and off. I use the GEM for convenience, so “messing” with it too much defeats the whole purpose.

I’m more interested in making the batteries last as long as possible than I am interested in getting the maximum performance out of them. Typically, I’ll make one or two short trips (less than 2-3 miles total) a few times per week on relatively flat terrain. If for some reason my charge is too low … no problem … I’ll drive my regular automobile (gasoline powered).

So … should I always keep the charger plugged in? … or … should I only recharge when the battery reaches a certain level of discharge? If it’s the latter, what level would be reasonable … 50%???

Thanks,

  • Simon
2

I believe it is best to plug in whenever possible. Especially in cooler weather. What really hurts the batteries are deep discharges and being left discharged. Shallow charge cycles will prolong battery life and reduce gassing and water consumption. Do not use tap water in batteries. You should never deliberately delay recharging the batteries. There is no need to open the master switch. If the GEM is unused for a week, unplug it and then plug it back in to restart the charger. The software for the Zivan NG1 battery charger (used in the 2002 GEM) has been updated. They can match the exact power requirements of your batteries. This upgrade also includes adding an exercise function that will keep the batteries charged without having to unplug and plug in the charger. Call Zivan USA Electric Conversions at 916-441-4161.

Daniel

3

[QUOTE=GEMmechanic;8470]I believe it is best to plug in whenever possible. Especially in cooler weather. What really hurts the batteries are deep discharges and being left discharged. Shallow charge cycles will prolong battery life and reduce gassing and water consumption. Do not use tap water in batteries. You should never deliberately delay recharging the batteries. There is no need to open the master switch. If the GEM is unused for a week, unplug it and then plug it back in to restart the charger.

Daniel[/QUOTE]

Daniel -

Thanks for sharing your expertise with the rest of us. I’m new to EVs and I really appreciate your help.

  • Simon
4

You put in new batteries - what is the brand and model number? That will determine what will be best, if they are the appropriate battery.
Call GEM Tech Support at 866.764.0616 with the VIN and they can tell you what the vehicle was originally equipped with and how the charger should be set for which algorithm to accommodate your battery for best charging.