2007 Gem goes to Turtle Mode with full charge

My 2007 Gem randomly will go into Turtle Mode with full/half charge. I tested all batteries and they are good. What else could be causing this? Thanks in advance for advise, David.

Pretty much batteries or connections. Did you test them under load?

Agree with Inwo here. Batteries or connections.
Can you describe how you tested your batteries and what indicated they are “good”?

Go through each and every connection with a good wire brush. Make sure they are all clean and tight.

Put your meter on the Pos and Neg connections on the controller and place it where you can see it from the driver seat. Note the Pack Voltage. Take your car out for a drive and watch how far the voltage drops when you accelerate.

Report back with your findings.

How long has the car been acting like this?

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Can you post your battery voltage measurements and when you got them(ie during charging, 1 hour after fully charged, etc)?

Also a good thing to do periodically is to feel the battery/wire connectors at each battery right after a long ride. If any are hot then it’s time to remove the wire, clean all surfaces and reinstall.

Thanks for your comments Inwo and Assyrequired.

I tested all the batteries (and all connections) under load and discovered 1 failing battery, which I replaced. I tested the battery’s with the following load tester:


All the battery’s performed under load, so I am pretty confident they are good. Which leads be to believe that it may be something else, like the charger or controller. My cart has an upgraded motor and controller, so I suspect the issue is with these components.

The batteries have all been successfully tested under load, so I think it’s the charger or controller.

So- Is there a timeline issue here? I am confused. Let me see if I got this straight…

  • Your car went into Turtle Mode.
  • You load tested your batteries.
  • You found a battery that failed under load, and you replaced it.
  • After this you load tested all the batteries again. They are all performing now.
  • Yet- you are STILL going to turtle mode?

After how long?
Is the turtle ever cleared at the begin of the test?

Note that we are asking for a bit more of the meaty details here but you are ignoring them. We need this info to make a more educated guess to helping you with your problem. Every question may lead to a tiny clue into what is actually going on.

It’s like-> calling your doctor to ask him why your arm hurts without telling him your dog is still biting it.

You found a battery that failed under 100 amp load. What do you think under a near 300 amp load when you launch from a dead stop?

A sled team can go as fast as the slowest dog. One bad battery will drag all of them down into hell with it

Replace the battery. It’s your problem

@davidreuter - Not mentioned yet:

What batteries you are using?
How old are they?
Are they balanced?

Your timeline is correct. Turtle mode occurred prior to replacement of the bad battery, yet it is still occurring after the bad battery replacement. The turtle mode “clears” upon charging the cart. Assuming the batteries are good, it seems line issue may lie with the charger (perhaps the charger is not properly charging) or perhaps the controller has an issue which is putting the cart in Turtle mode.

What I see missing here is now that one replaced battery was brought up to the SAME capacity as the other batteries? Normal setup is replace all batteries with all brand new same mfg/size/etc and charge. But once you pull one out of line after being a problem not only are the charges on the other batteries likely off from each other but the one added back is also not ‘balanced’ with the other batteries.

What you need to do is put each of the 12V batteries on a decent 12V charger and take them one-by-one to the same fully charged state. Then run it for 5 miles or so and put it on the onboard charger and go from there.

And of course all of this is while maintaining the correct acid fluid levels in the batteries using only distilled water for topping off.

Thanks for the advice. I will charge the batteries one by one to ensure they are all “balanced”. Then reconnect and do a driving test.

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I recommend you measure each battery after all have been charged and write them down. Then do the drive, measure again and write the voltages down. Recharge and 1 hour after the charger is finished charging measure a 3rd time and write down the voltages. Post those 3 sets of 6 readings here and we should be able to tell you the good, bad and the ugly of what’s going on.

Will do. Please confirm recommended procedure:

  1. Initially charge & measure each battery individually (requiring each disconnected)

  2. Drive

  3. Measure each battery again individually (requiring each disconnected)

  4. Charge all batteries via cart charger

  5. Measure each battery again individually (requiring each disconnected)

You don’t need to disconnect each battery when charging with a single 12V charger. Just move it from battery to battery. But it would be a good idea to flip the main disconnect so that nothing is draining the pack while doing this. You also don’t need to disconnect anything to measure the voltage on each battery. Just connect the 2 leads from the multi-meter to the Pos and Neg terminals of each battery one by one.

And be sure to wait at least one hour after the cart charger has finished before measuring the batteries one last time. You want the “float charge” to dissipate before you make the measurements.

Good, that makes is much easier.


I love this guy! He understands!

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But wait!
Its a 2007 car.

Meh. Guilt by association.

He dies.
She dies.

Thanks for everyone’s input. Here is an update on my “turtle mode” issue:

I charged all batteries independently with a Napa 12 amp charger. The (5) 2yo Deka batteries each got to 14.2V and 80%. The new AMP battery got to 100%. I then charged all batteries from the Gem charger, which started at 80%, after 90 mins was 90%, and eventually got to 100% (ending with “CC” reading, which I assume means “charging complete”). I travelling this week and will test the Gem upon my return, but my suspicion is balancing the batteries will fix the issue. If you don’t hear from me, assume it fixed. Thanks again.