Cart is acting weird

[Warren2129]

Hi guys, I just bought a 2013 ezgo txt that was refurbished in 2017 so o was told. Well I was told the cart hadn't been riding much lately and the batteries may need charging. I got home put it on charge, later that day I went to test drive it and the batteries were still week, so I checked the batteries and the water was low in all the cells, added 2 and a half gallons of water, left the cart on the charger for about 16 hours. Took it for about a 3 or 4 miles test ride, did great. Went to put back on the charger and the charger is reading full charge. Now here is where I got lost at, the cart is now really week at times, yes at times, sometimes it runs out good and is strong and then sometimes it is weak and barely goes. I checked the throttle thing under the floor board, it looks new, it did have one corroded wire in the throttle plug near the controller so I pulled that wire out of the plug ends, cut them and put new connectors on, it did not help. I have loosened wiggled and re tightened all the battery wires and motor wires just to make sure they were getting good connection. What could be causing the cart to some times work and sometimes be really weak, and it has done it while riding it and have to limp back home. Batteries are 2018 crown batteries, each battery is now checking at 7.98v with a total of 47.98 volts. But I feel like it should be charged some anyways after riding it several miles but the charger is reading full, not showing that anything I wrong with the batteries either. I am lost. Could it be my batteries? I have to buy a new set and that not be it. I don't have a amp load tester to check the amps so all I can do it a voltage check, and it seems like it's pretty close. Also when I first did the test tje batteries were reading 8.23 volts, then after a few test drives just outside my shop to see it I had fixed the issue it is now reading 7.98 volts. Any info is greatly appreciated, it has stomped me, and I am definitely upset with myself for buying this cart when I had a fee other options with new batteries and ready to ride, which this one was suppose to be ready to ride as well. But it is what it is, I've got it now and I need it fixed

[phipps33]

I’m no means an expert, just getting into electric carts myself, but your battery voltages are low. Shouldn’t be under 48v. Here is a nice battery voltage chart....

[meimk]

Having been left low on water and unused / not charged for a while I'm afraid your battery pack may be shot. The chart provided by phipps33 tells the tale. Letting them get below that 50% line (8.07 volts each / 48.41 volts for the pack) is damaging the batteries. Any time the water gets below the plates it will damage the plates in each of those batteries. You've got several strikes against you in this case. With proper water levels in all the battery cells, run the charger till it shuts off by itself. Let the batteries sit for at least 12 hours after the charger has shut itself off. Test the battery voltages at that point - after sitting, before driving. Let us know what you get and we can discuss what it means in relation to the above chart. Good luck, but prepare yourself for some bad (expensive) news.

[Warren2129]

Looking at the voltage chart I am a little low, but my charger won't charge them, it runs through the "cycle" and says they are charged, the charger isn't even coming on. Now I did let the batteries charge for about 16 hours and when I unplugged the charger it was still charging, by the lights on the charger I think it was almost finished, unfortunately I didn't let it sit before I ride it, I was excited to see if the batteries were ok or not. And now the charger won't even try to charge them. I wonder if I should find a charger to borrow and see what it does. But even if that is the case then my batteries is probably still not to great if they are dead after about a total of 5 miles or so.

Just talked to the guy I got it from and he did confirm that the batteries sat for a while not being maintained and wasn't sure of their condition. So that may be my issue. Seems like the charger would pick up that they were bad though.

[Bama Brad]

I would suggest that you clean/tighten all the battery cables, see if that makes charger "see" batteries again. Put on 2-3 complete, overnite charges with about 12 hours between each charge. This will sometimes revive batteries to a reasonable state of charge. Also, feel to see if anything is getting unreasonable hot. Some times cable corrosion isn't easily seen because it's under the plastic. As others have suggested, there is probably damage done to them but you may be able to get another year or 2 out of them.

[bronsonj]

check the plug where it connects. It sounds like your batteries need charged but your charger isn't doing it. I had that issue on my 2013 TXT48 and of the three little metal pins (I think they are called 'radsoks') one was bad. I found if I jiggled the charger plug where it goes into the seat then it'd make contact sometimes.

I'm thinking your first issue is getting the charger to realize it's plugged in or that maybe your charger is not doing well. At 48v your pack is dead but that is plenty for the charger to realize the batteries are there and need charged. Also, the charger won't charge if it doesn't sense the battery voltage, it could be just a bad connection.

I let my batteries go so low that the plates were exposed once, back when I had Lead Acid batteries. That absolutely shortened their life but I still was able to use them another 14 or so months. Just depends on how far you need to drive.

But, step 1, address the charger issue.

[Warren2129]

Ok, so I charged each battery individually with a 12v 8amp car charger for about 30 mins each, then hooked my cart charger up for about 19 hours, I could here them bubbling pretty good so I know something was going on. I checked the voltage rigjt after charging and it read 55.7v. About 10 hours later I hooked up a battery tester, the toaster style, to each individual battery, they went from 8.2v to 7.2v in 10 seconds. I then checked the total voltage and it was at 49.8v. I drove the cart a little and now they are at 49.4v. So by the voltage chart it seems somewhat ok other than them being at 55.7v when I unhooked the charger. I am in the process of looking for a charger I can borrow to see if that is my issue.

[Warren2129]

Just rode 5 miles, 2.5 miles there 2.5 back, pedal to the metal 😆 batteries at 49.4v. Maybe it's something with my charger.

[JohnnieB]

There are three different battery voltages.
1. On-Charge: The battery's voltage while being charged. Starts at whatever the battery was discharged to and climbs up to about 2.70VPC (Volts Per Cell), which is about 64.8V for a 48V pack since it contains 24 two volt cells. (Also depends on type being used.)

2. At-Rest: Voltage measured about 12 hours after charging. The batteries acquire a "Surface" charge while charging which contains very little stored energy and it takes several hours for the battery's chemistry to equilibrate. The opposite happens when amps are drawn from the battery, but it only take an hour or so for the chemistry to equilibrate after being loaded.

3. Under-Load: Voltage measured while amps are being drawn from the battery. The more amps drawn, the lower the voltage drops to. Voltage drop is almost instantaneous, but recovery takes some time.

At-Rest voltage are what is listed on the SoC chart posted earlier in this thread.

Automotive type load testers are not accurate with deep-cycle. They will identify bad ones, but cannot prove good ones.

Load testing of deep-cycle batteries takes a $pecial test set.
For 8V deep-cycle, a constant amp rate of 56A is drawn (at 80°F) and the time it takes to discharge to 1.75VPC is measured.

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What is make/model of you 48V charger?

Which model Crown batteries?

[Warren2129]

Delta-q
913-4810-E3B