Gem Car - 72 volt electric

[dcannow]

If they are lead acid. You have to charge each one up to a minimum of 10 volts for the on-board charger to kick in. I had Gel battery conversion (new charger required) but I think charging each one would work the same for them.

[LostHusker]

Originally Posted by yoyomina

hello Railcop094,

I was wondering if you could share with us how to revive the batteries. I have a 2005 GEM eS and the batteries are dead. I get about 0.5 volts from each. I plug in the car and the batteries don't charge and I don't even get the cluster to illuminate or the lights to work.

You realize that this original thread is two years old right?

[railcop094]

My batteries were getting about .75 to 1 volt per. I have large stand up 40 amp battery charger that I use. I unhooked the cables from each battery and charged each battery separately for 24 hours, total of 6 days. As I unhooked the charger I would be getting almost 13 volts. After sitting for 24 hrs I rechecked them and was still getting 12.7. They are all holding a charge now and charge normally when I plug it in.

[yoyomina]

If it matters, my batteries are Gel.

[dcannow]

Good Man You might want to run it some distance to get the voltage down again and and plug in your on-board charger. It may take a few "cycles to get them to hold the charge. You can tell in a hurry how you are doing by hitting a couple of hills.

[dcannow]

I was told Gel batterires had to charge at a slower rate than Lead-Acid, hence the reason for change of on-board charger when switching to Gels. (Per Gem Service dept.) You might check this out if you have to use the stand alone charger again.

[yoyomina]

Thank you all for your help. I will start charging my batteries tonight with a 2/6 amp car battery charger. I guess I should use the 2 amp setting.

[railcop094]

My batteries are gel. My on board charger is set up for gels but you have to have at least 10 volts per battery for it to charge them. The ol' guy that told me how to charge them has been rebuilding golf cars for years and he deals mostly with batteries. So I gave it a try. Once I got all the batteries charged, my on board charger worked again. So I don't have to use a stand alone anymore.

[yoyomina]

O.K. so I have charged 4 out of the 6 six batteries for 24 hours each. I used a 6 amp car battery charger. Immediately after charging some of the batteries have about 9 volts. I rechecked the batteries a few hours later and the voltage drops to about 3-4 volts. Some of them show 1 volt 24 hours after charging.

Are my batteries bad?

[railcop094]

I don't know that 6 amp for 24 hrs will get the job done. I was charging with 40 amp on 12 volt high. It's 40 amp on the boost setting. I believe it is somewhere near 20 on high.