G29 DR2 48 volt very slow going up hills

[Mpk200]

Hi
I’ve just purchased a 4 year old ex fleet G29 Dr2 48 volt.

The cart seems very slow going up hills 6-8 mph.

The batteries are Trojan 6x8 volt Dec 21.

Ive tested the batteries on full charge they show 50.2 volts each battery showing 8.2 except one showing 8.00.
On load with a flat run the batteries drop to 48-49 and im getting 13-14 mph.

Going up a gradient the battery pack drops to 42-43 and speed at 6-8mph and it feels like its not going to make it.

Just run 4.53 miles and the batter gauge is just bellow 1/2 on the gauge.

Does this look correct?

Im very happy with the cart other than the speed of the cart.

Any help will be greatly appreciated.

Thanks

[ojo]

You definitely have a problem with the batteries, at least one is very bad Good Info about the battery pack. 8v is only 40% SOC, and 8.2v ~ 60%! I'm a big Trojan fan but, that is worse. Enclosed a chart for Trojan battery data.

[Mpk200]

Thanks for your time to respond.

So your saying that the battery that was showing a 8.0 volt is a bad battery?

What other way could i try and isolate the bad battery.This battery had a little corrosion on the terminal which I've now cleaned and have it on a charge over night to check tomorrow.Not sure if this would cause the battery drop.

Thanks

[ojo]

Compare with the battery chart, 8v is pretty dead. Fully charged, with a rest time of ~ 10 hrs, you'll have ~ 51v on the pack or ~ 8.5v on each battery. All batteries should be close together within .01 - .02v. Clean terminals are important and the correct fluid level also.

[Volt_Ampere]

Test the drop on each battery as you go up the hill. Fully charged batteries should not drop that much. Sounds like the batteries are not very good. For a fleet cart, your level ground speed is normal but it should not drop much going up a normal hill.

[Mpk200]

So after overnight charge this is what my batteries are at.

Pack-51.3
1 - 8.6
2- 8.5
3- 8.3
4- 8.5
5- 8.6
6- 8.5

The battery that was all corroded is battery 3.

I cant do a load test until later as the golf course is busy at the minute.
Would the solution be just to replace battery 3 ? Or advisable to do the whole pack which would make it a expensive 2nd hand golf cart.Batteries are stamped Dec 21 so not that old.

Thanks

[Volt_Ampere]

Until you load test, it's not possible to say the condition of the batteries. I assume you have checked the water levels. A pack less than a year old should be good unless it was really mistreated.

[Mpk200]

Just done the load test (managed to get out before the ladies)

This test is up the best hill i could find in the time i had.
1-7.6
2-7.6
3-7.4
4-7.6
5-7.6
6-7.7

Pack dropped to 45.3
Water levels all good and terminals except one was very clean,all cleaned and charged overnight.

The cart was purchased from Yamaha in another state from a fleet at a course .Nothing saying that this cart or the other 20 he has ,has been sat uncharged for a couple of months you just dont know.

Hope this helps .
Thanks again

[Volt_Ampere]

Certainly not great under load but none are way worse than the others so replacing one isn't going to do much for you. I would use them until you decide to invest in a new pack and / or some upgrades. There are lots of options out there including Lithium , aftermarket motor and controller, larger tires, etc.

[ojo]

Very impressive, how fast you got the test results as i've learned here from the big brains, healthy batteries shouldn't drop more than 2 - 3v, even uphill. I think, something went wrong with these Trojans in the past. In a year, they should be better than new ( broken in ). As the performance is bad, i'd recommend to replace the whole pack. Probably with lithium.