Cart Jerking

[Camaro69]

A friend of mine has a 2008 Precedent with Trojans T-875 from 2016. Every once in a while the cart will jerk and then be ok. His yellow dash light is 1 year old and doesn't come on.

I'm going to look his batteries over tomorrow and first thought that since he only has the cart for 2 years that maybe the Algorithm isn't correct, but he doesn't have the Eric charger, see below.

Will be checking, water level, terminal connections and doing a voltage check on the batteries, plus a load test.

Any other ideas?

Thanks

[CP241]

2016, those batteries are 6 years old. I’m gonna guess it’s time for new ones. Check all the cables and connections too, they’re probably original and a bit crusty. I’d probably put my money on new batteries and cables if I were a betting man.

[Tom47]

[Camaro69]

Checked the cables and all are tight. Water level was a little high on all cells.

He charged the batteries until last night and pulled the plug. So it's been sitting for about 15 hours.

Did a multi meter test as follows:

1- 8.49
2- 8.46
3- 8.47
4- 8.49
5- 8.52
6- 8.44 = 50.87

Ran the cart down the street for a little load floored as follows:

1- 7.74
2- 7.68
3- 7.65
4- 7.70
5- 7.45
6- 7.68 = 45.90

Plugged the cart back it to charge and his dash light didn't beep 3 times like my Eric charger. His has a Power Drive 3 charger.

Watching his charger, the dial needle went to the far right. After a few minutes went down to zero and then back up to about 4/5 of the dial. Then slowly went down a few bars, then back to zero and then up to about 10 amps, back to zero after a few minutes and up to around 7 amps.

Is that normal for that type of charger?

Thoughts on his batteries or any other reason why the cart jerked under heavy load then was ok?

[Tom47]

Batteries 1,4 and 5 are 100%. Batteries 2 and 3 not quite 100%. Battery 6 is at 95% so is not charging fully. This one may be dragging the pack down.

The running amperages are not surprisingly low at max speed. Was each battery checked while driving? If so, #5 is low, but #6 is ok. If not, hook up the voltmeter to #6 and check the voltage during hard acceleration.

Maybe several more charges will bring the batteries in line. I'm not sure about the Powerdrive 3 operation but it probably is doing a balance charge. Several of those may make a difference.

The batteries are near the end of their service life, however. That doesn't mean they will die soon. My 2013 Crowns lasted 3 years past their expected service life service life and were still serviceable when I pulled them out to install the lithium.

Is the cart still jerking?

[Camaro69]

The 2nd set of numbers was with the pedal floored but not up a hill.

I figured at 6 years the batteries are near the end, but told him to ride it out to see if he makes it for this season.

Thanks

[Tom47]

[Lochlin]

I am a bit out of my realm with this one but is that an AC or DC cart? If DC the motor brushes could be going bad.

[Tom47]

Originally Posted by Lochlin

I am a bit out of my realm with this one but is that an AC or DC cart? If DC the motor brushes could be going bad.

It's a DC cart and you are right, brushes are a possibility on an older cart. Not as likely on a 2008. It would be worth looking at them though.