2008 Battery problems, or charger issue, help troubleshooting

[chuckynorris]

I have a 2008 ezgo txt pds 36v vary with the "speed" jumper installed.

4 of the batteries are 3 years old.
2 of the batteries are only 1 year old Trojans.

All batteries measure 6.2-6.4v when charged.
The in dash meter shows full.
The cart can go about 1.5 miles with pep, with the meter only dropping 1 light, but then it just dies.

All connections look clean and tight.

I'm willing to just buy 6 new batteries if I must, but I feel like something else must be going on here, and I'd hate to invest in new batteries to see the same problem.

Why isn't the battery meter dropping all the way(or at least mostly) down when it dies? Could this mean my batteries could be good but something is impeding the current to the motor?

Thanks!


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[yurtle]

We need battery voltage to two decimal places.

Connect a DMM to each battery and drive it up a hill, and see if any batteries drop more than others. Maybe you'll get lucky and on;y have one bad.

You should never mix old and new. The old ones will cause the new ones to age rather quickly, and soon you'll have a bunch of old batteries.

Measure pack voltage 12 hours after a charge completes.

[chuckynorris]

Thanks for the quick reply.
I'll need to get some gator clips to keep the DMM attached to the terminals while driving. I'll report back in a few days.

Also, the two new batteries were replaced under warranty by the shop that sold me the cart... So I'm not too worried if I don't get optimal life from those.... I'm willing to replace all 6, I'd just like to understand why the meter isn't dropping to near zero when the cart stops.

Hopefully once I get more info, that will help.


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[yurtle]

Originally Posted by chuckynorris

Thanks for the quick reply.
I'll need to get some gator clips to keep the DMM attached to the terminals while driving. I'll report back in a few days.

Also, the two new batteries were replaced under warranty by the shop that sold me the cart... So I'm not too worried if I don't get optimal life from those.... I'm willing to replace all 6, I'd just like to understand why the meter isn't dropping to near zero when the cart stops.

Hopefully once I get more info, that will help.


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You can always just tape the probes onto the battery terminals.

[sprockket]

I am not sure how accurate the bar meters are. I installed a digital meter in dash and it's probaly the best money you can spend to be able to watch what is happening with your batteries at all times. It's also a way to keep an eye on how your charger is working also.Highly reccomend the volt meter Scottyb sells. Also check your battery water levels and charge your batteries as often as you can. After every use if possible no matter how long you use your cart.

[chuckynorris]

Thanks for the help so far. Here are the results of taping the probes and going to more decimal points.

Total voltage across all 6 before any driving: 37.6
Each battery before:
1: 6.36
2: 6.37
3: 6.27
4: 6.23
5: 6.21
6: 6.22

I taped the probes to the battery 1 and then battery 6 to measure the lowest voltage when going uphill.

Battery 1: dropped to 5.80
Battery 6: dropped to 5.49

Total voltage across all 6 after driving test: 37.4
Each battery after:
1: 6.35
2: 6.35
3: 6.24
4: 6.20
5: 6.17
6: 6.18

Note that I referring to batteries based on this picture/label

As I mentioned above, batteries 1&2 were replaced last year under warranty from the shop I bought the cart from 3 years ago... Those are newer Trojan batteries, so I'm not surprised they are testing better than the other 4.

The other 4 are 3 years old worldwide batteries.

Probably statement is that I can go about 2 miles total before cart runs out of juice.
Battery meter historically worked well, but now it never drops more than 1 or 2 positions.. So cart dies when gauge still looks like it has >75% power.

For reference, this is the meter at full


Question ...
-Should I replace all 6 (and feel confident that will resolve my range issue)
-Replace the 4 bad ones... I know it's not ideal... But if the two Trojans are "good" is that best?
-look into something else that might be the real issue (charger or something else) before I sink $$ into new batteries that might not fix the problem.

For reference, I'm using this charger... And it's almost always left plugged in when not using.


Thanks!


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[chuckynorris]

Originally Posted by yurtle

You can always just tape the probes onto the battery terminals.

Thanks! I appreciate the help.



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[yurtle]

Are batteries 1 and 6 the bad ones, as you said? 1 is a newish one.

As to charger, not all chargers will keep your batteries topped off. I'm not familiar with yours, but many require you to unplug from cart and replug to re-initiate a charge, every 2 - 4 weeks. I used to do every two weeks.

EDIT: Ditch your battery meter and buy one of these:

https://www.cartsunlimited.net/battery-meters.html

Use it with this chart:

Assuming battery 1 is not one of the bad ones, you may be OK buying just four. I'd wait and see what others here say. I have no experience in mixing them, but worst case, you'll get one year less out of the four you buy vs. buying all new ones now. So it's really just a matter of paying over $200 less now, but buying six a year sooner. Again, worst case, but folks I trust have said this is pretty much what happens.

[chuckynorris]

Batteries 1&2 are the newer ones.

Per this chart, they are starting at ~90%.

Batteries 3-6 (older worldwide) are showing as starting in the ~75% range on the chart.

I'm tempted to save $200 and just pick up 4 new ones... I likely just get interstate batteries at Costco. Anyone have any experience with these?



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[yurtle]

Originally Posted by chuckynorris

Battery 1: dropped to 5.80
Battery 6: dropped to 5.49

1 and 6 are bad.