2009 battery dilemma

I have a 2009 e6 which I purchased a little over 3 yrs. ago. When purchased the batteries were old and I sent it to a GEM certified shop in March of 2018 to have them replaced ( they also did some other “housekeeping” at the same time).

Recently she has been driving fine for about 12 miles and then once down to 4 green bars all bars suddenly vanish and she goes into turtle mode.

I sent her to a local, well respected, golf cart mechanic who also has experience with GEMS ( the original shop I used is 2 hours away ant this guy is only 30 minutes away). He has put her through her paces and says that the batteries are beginning to fail. He has talked with a GEM dealer who says the gel batteries I have (APG?) are sometimes know to fail in 3 yrs or less.

So here is the dilemma - Do I bring her home and just make sure I recharge after 12 miles (or will that battery time begin failing more quickly now that they have started to fail). Or, do I replace with gel batteries now and just hope they last longer than 3 yrs next time? Or, do I do the conversion to the lithium batteries (I’m really a bit concerned about putting that much money into a 2009 vehicle)? Or is there an even better battery option just around the corner and I should nurse the current batteries until that is available.

The shop that has her now recently did a lithium conversion on another GEM that was in the shop last month. I’m not sure if that is their first one or not.

I am content with a max speed of 25 mph, I only drive her on roads, and the terrain is flat. The majority of the time I travel alone but do regularly take a full load of friends/family around town. I drive her daily (but never when it is precipitating). Some days it is just a couple of miles but it is not uncommon for me to put 15 or more miles on her in a day (with little opportunity for charging during that time)

As you can probably tell I am not handy with mechanical tasks (just a retired teacher who loves her GEM). Helpful suggestions on which direction to go would be appreciated. We are located on the Eastern Shore of Maryland.

If you can find out more about why the pack is failing it may help.

Sometimes it may be just one battery. That will dive a whole back to turtle real quick.

Replacing one battery is not the greatest plan, but it may buy you some time to sort out what you want the car to be.

The mechanic put it on a load tester? I don’t understand all the terminology but it seems as if all the batteries are failing equally. I had hoped it would maybe be a problem with just one but that doesn’t seem to be the case.

Key here is how much work he put into the test. He really should have tested each battery (individually) with his load tester.

Or - if he measured the voltage of each battery as the whole pack was under a load (just like you were driving). Testing once overall as a pack there is no way to tell if one battery dumped or the whole pack was dropping equally. A single battery dropping will show up as you are probing.

If all were failing equally that would be amazing.
Perhaps he is just trying to sell you six new batteries? This is not saying he is actually a crook, just an attempt to educate you a bit so you can spot a crook vs a good guy.
In reality, a guy trying to run a business and keep his employees fed is not an easy thing to do these days.

Sure - It is totally possible to kill a set in less than three years, but that means something is wrong with your system and you might do the same to the next pack.

  • cheap/incorrect batteries (I don’t know APG)
  • incorrect charging profile
  • user consistently driving past the lower threshold. (driving it till you push it home)
  • letting the pack go dead when not using the car (off season?)
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I would advise against putting in new gel batteries, for the same cost or less, you can get lithium batteries. I know @Inwo and @LithiumGods are making some batteries with pretty easy setup and installation

The mechanic says that they tested each battery individually and also put them on his “big load tester 3 at a time”. All batteries are failing at about the same rate. When I sent it in to the shop he had mentioned that the problem could be with just one or two batteries but apparently that did not turn out to be the case. This shop has an excellent reputation locally (they are extremely busy with carts coming in from all over the region) and I guess I am just going to have to trust him on this…
He says the charger looks like the original and as far as he (or I) know the cart came with gel batteries from the factory. So hopefully the charging profile is correct.
I pamper this cart and have never had to push her home. Twice in the past 3 years the rad turtle has shown up when I was more that a half mile or so from home. In those two cases I plugged her in at friend’s homes until sufficiently charged for the return ride. We drive her year round, even in the winter (I have the plastic sides). On the rare occasions where I was not able to drive her for more than 4 or 5 days I pulled the fuse until we were ready to roll again.
If we get new gel batteries he suggests that we also send the charger out to be checked (I guess the programing?)
If I decide to go with the lithium batteries he plans to use “Allied” batteries and the charger that is sold for those batteries. He says we would only need 4 lithium batteries rather than the current 6. I asked about the need to build a new rack system and he says he will probably only need to add one support strap to help keep things in place.
I call tomorrow for pricing on the two options…

Don’t do the Allied lithium. Just looked up what they offer. Grim.

Same battery pack each time. Just changing around the internal wiring. 12v “battery”=100ah. 72v “battery” = 18ah. Easy math, eh? Same form factor and weight too.

Not sure how he plans on doing it with 4 batteries. Allied only offers 12, 24, 36, 48, 72. 2p2s w/36 is most logical, but 36v are only like 40ah. Your range might take a hit.

How much draw will they handle? I see 250amps+ on my bms every time I mash the throttle.

And at $1k/battery? Kerist, I’m in the wrong business…

Hehe. Quoting this because it’s funny when you say it in your head in Slim Pickens voice.

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Thanks for your insight. I visited the shop today and was there when they called the battery dealer. Once the dealer was told my car was a 6 seater he recommended we go with 6 batteries (like you said).

I am afraid I do not understand the “ah” stuff. Will going to 6 batteries help with that?

I’m thinking one of the reasons the shop would like to use the Allied batteries is that they can be dropped right in. Is there a brand that would also be able to be dropped in but that would be a better quality and/or less expensive?

The quote he gave for 6 new batteries installed with new a charger was $5,980 Yikes!!!

The price is only one problem with one size fits all drop in 12v batteries. You have the same issues as lead only worse.
When one battery gets out of sync everything shuts down. They need to communicate between them to work together properly.
Each one has it’s own bms. Bms in series don’t play well together, as each 12v battery sees the full 72v under certain conditions. I’m sure the battery companies try hard to overcome this. But why?
Just build the proper 72v battery with a single bms. (battery management system)

AH= the amps a battery can deliver in one hour.
At 30mph a Gem can use 250 wh per mile.
That’s 3.5ah per mile.
a 100 ah battery / 3.5 = ~30 miles.
Very rough best case est. Subject to large losses in lead batteries and driving style.

Hard for me to go into too much detail without putting on my sales cap. My hobby after retirement is electric vehicles. Specifically batteries and high performance. I buy whatever I can find surplus and reconfigure to work in specific cars. Marking them up an obscene amount to cover my addiction and working pretty much full time on helping forum members.

E6 is going to be a 7.5hp hi torque motor and 14.something:1 gears. It’s a heavy beast even empty. 500 amp disconnect

Then add nearly 1500 lbs of people.

5k s a lot for a blue smoke display.

GEMs are not golf carts.

Holy cr@p!!
That is a scary thread filled with more than one bad example that burned buildings to the ground!!

All centered around Allied Lithium?

Nice find, Inwo.

I should talk. My brother lost everything in a fire. He had forklifts and other vehicles using my batteries.
However, nothing was charging or in use, and it was determined NOT to be the cause of fire.
Keeps me on my toes, safety wise.