Charging Tips/Best Practices (2002 e825 w/ gel batteries)

Hi all, only my second post, so pardon if this has been covered. I did a quick search and couldn’t really find a basic/beginners take battery charging (for gel specifically anyway).

I just picked up a 2002 GEM e825. Batteries were replaced in November 2021. I am looking for basic tips and best practices to maintain the batteries, maximize range, and hopefully not leave myself stranded.

How often to charge?
Should I always leave it plugged in at home?
Should I make sure it is discharged a certain amount prior to plugging back in?
Ideal max discharge amount
Am I even asking the right questions?

I welcome any thoughts this awesome community might have. Thank you!

Battery type: Deka 8G31DTM Group Size 31 Marine Gel Battery | Battery Mart

How often to charge?

Every time you are done with it for the day. Or if you get down to low battery levels and you are not done with causing neighborhood havoc. Every time you go out you need to ask yourself, “Will I need a speedy getaway?”.

Should I always leave it plugged in at home?

Sure, if you want to unplug it when you are done charging, this is fine. Make sure you switch the battery off if not using it for a couple of days. If you are leaving it parked for months you should have a topping off plan.

Should I make sure it is discharged a certain amount prior to plugging back in?

No. That is ni-cad thinking.

Ideal max discharge amount

The general idea is to never discharge past 50% SOC. It takes end life off your pack. Judging where that 50% is the tricky part. The SOC display on your PID may not be accurate(it totally depends on how it was calibrated). To check- run down your pack a bit (50% on your dash?) and check your battery Volts with an external meter and compare it with this table. Your display may be set to show 10 and that means 12.00 on your batteries.

12v battery SOC%

Don’t just check one battery and assume the others are the same. Since this is a new car to you, Check your pack for proper balance. A happy pack will have all batteries within 0.1v from each other. If they are tighter that is even better. An unbalanced pack can have one (or more) battery 1.0v lower than the others.

The concept here is that when the first one hits 12.0v you need to stop. Even if all the others are at 12.2 and the cart still feels fine (But who does that? How can you tell?). Short of installing 6 individual monitors there is no way to know.

The fix is to boost that low battery with an external charger and try to bring it up to the level of the others. If you are lucky it will come up and stay there. But your batteries are 6 mos old now so it may be set where it will live now.

Am I even asking the right questions?

It is the questions that you don’t ask that will get you into trouble. That builds experience, sometimes scars.

How does one do this?

Do you have a suggestion for a good (cheap) external meter?

All in all, seems a bit more like dark magic vs. science.

In a related bit of news, I took it our for a ride yesterday, all good. When I plugged in after, the charging indicator light blinked red. The fan on the charger was on, but guessing blinking red isn’t good. I have plugged in to a regular old 13amp, 125V extension cable. Batteries are new from November.

Appreciate the help!

@AssyRequired is good with dark magic. Ask him about listening to motors with a stick

This it the normal guide. If it flashes it is usually also beeping. If you can’t hear it you will need to scrounge up a stick…

I’m getting an initial beep, two I think, then th red flashing.

Any tips on that meter? Would assume that’s what I’d need to check the ‘nominal’ voltage?

Just checking, how do I turn it off?

This type of thing work as a good external meter?

Under the seat is the master on/off switch.

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