2009 CC Precedent Low Speed Lurching Trouble

[dmortonjr]

Hello to all. I'm new to the site & need some help. I bought a 2009 48V CC Precedent last week from a not so local shop. Makes for some difficulty getting service. Anyhow, I'm having trouble with low speed operation. Acceleration from a dead stop is not smooth & the cart tends to lurch a bit. Also, it has a tendency to surge (in other words, with a constant accelerator foot pedal position, speed is unstable) at lower & midrange speeds. This cart has a light kit & I see that the lights dim & brigthten in conjunction with the surging. Thanks in advance for any advice.

[kvnjcksn]

Hey! I am from Carolina Beach, NC and I experience similar symptoms with my 09 CC Precedent. Any luck yet with the fix?

[gaminde]

Bad connection bad battery bad wires your loosing voltage

[dmortonjr]

Gaminde, thanks for your response. I know from reading the posts here in the forum that you're one of the masters. Electrical issues are not my strong suit, but I just took a look at your web site for the 2 speed kit & see that you know how the electrons flow. Kit installation appears to be pretty user friendly with the wiring harness. This looks like something I'll be interested in once I get my low speed problem resolved. In any event, I checked battery & motor connections & all are clean & tight. I checked battery voltage with a multi-meter after charging over night & read individual voltage between 8.16 - 8.46V & 49.8V across the entire stack. I understand your logic at a high level, but I don't understand why there wouldn't be trouble at high speed with a connection problem, etc. Any additional suggestions would be greatly appreciated.

[rs2003ls]

I have a 2009 Precedent that would surge at top speed. Holding the pedal down and going full speed the cart would slow and then speed up. I work at a golf course and we have been having a really bad issue with the MCOR going out and causing this problem. Not sure how that would cause problems with light though. We have had to replace over 27 MCORS out of our fleet of 75.

[gaminde]

Gaminde, thanks for your response. I know from reading the posts here in the forum that you're one of the masters. Electrical issues are not my strong suit, but I just took a look at your web site for the 2 speed kit & see that you know how the electrons flow. Kit installation appears to be pretty user friendly with the wiring harness. This looks like something I'll be interested in once I get my low speed problem resolved. In any event, I checked battery & motor connections & all are clean & tight. I checked battery voltage with a multi-meter after charging over night & read individual voltage between 8.16 - 8.46V & 49.8V across the entire stack. I understand your logic at a high level, but I don't understand why there wouldn't be trouble at high speed with a connection problem, etc. Any additional suggestions would be greatly appreciated.

okay here is my thought you have dimming lights this means low voltage or bad battery connections, resistance. If you have a car and it runs out of gas And you need to push the car for me the hardest part is getting the car rolling once it's rolling it's much easier to maintain a rolling vehicle. So starting off would be harder on the electrical system and put more load on everything. So you gave us static voltages more helpful would be under load voltage clip the meter on the battery pack and drive it slowly, then clip it on each battery individually and drive slowly I'll bet that 1 battery that's lowest drops much lower than all the rest. Let us know what happens

[dmortonjr]

Gaminde, thanks for the education. It helped put things into perspective. I followed your advice & recorded the following while attempting to maintain the same speed for measurements:
Bat 1 - static 8.28V, slow roll 8.18V
Bat 2 - 8.08V/7.92V
Bat 3 - 8.29V/8.17V
Bat 4 - 8.42V/8.26V
Bat 5 - 8.39V/8.23V
Bat 6 - 8.32V/8.18V
Series - 49.6V/48.4V
Voltage drops range between 0.10 - 0.16V. I'm not sure what the threshold is for a battery that's bad, but Bat 2 drops below 8V with just a light load. Is this enough to cause trouble? Thanks in advance again.

[gaminde]

Real nice job of checking voltages, before I did any thing else I would put a 12 volt charger on the 1 battery for 2 to 3 hours let's see if you can pump some life into it. Even if this is not your problem (doubt it) it will need to be fixed first.

[dmortonjr]

Gaminde, Charged the weak battery with a 12V charger at 6A for 3 hr's. Appears to have breathed a little life into it, but it's still low relative to the others. Measured no load at 8.20V & slow roll at 8.06V. I'm guessing this battery is not completely down for the count, but as you suspected, I'm still limping along here. Low speed operation is still erratic with the cart surging at a constant foot pedal position. Please let me know if there's more I need to do with this battery or what I should look at next. Maybe battery cable resistance? Thanks for your help.