Stealth XR slow on hills

[bigcontender]

I just bought a 2009 Stealth XR from an auction. The cart looks like new, battery's are NAPA Duracell EGC2 bought 11/2019 48 volt system , with 4 x 4. The battery's seem to test ok voltage 6.31 to 6.36 aprox 10 hours after charging.

The cart goes ok on the level (maybee 15 mph) but slows to a walking pace (5 mph) on the hills in my development. The 2 hills I tried it on are not extremely steep.

This is my 1st cart so I have a lot to learn to trouble shoot this problem.
I don't have the owners or the service manual on this cart. Are there any manuals or circuit drawing out there for this cart?

[gyroman]

You need to give us your battery readings under load. Give us the total pack voltage while driving and each individual battery voltage while driving. And as always make sure all your connections are clean and tight and nothing is getting hot.

[bigcontender]

Ok did some testing this morning. Hooked up 4 voltmeters a digital angle gauge
and a gps to record max speeds.
Grade 4% downhill 20 mph, 4% 10 mph, 6% 9 mph, 10% 7.6 mph, 13% 5.8 mph.

Voltages initial 50.65v, #1 6.34v, #2 6.29v,#3 6.32v,#4 6.35v, #5 6.33v, #6 6.25v, #7 6.39v, #8 6.38v

Voltages on 6% grade 45.28v, #1 5.33v, #2 5.75v,#3 5.78v,#4 5.71v, #5 5.72v, #6 5.79v, #7 5.53v, #8 5.67v

Also checked 2 20 amp fuses allok voltage 31.4 v ????

The 12 v accessory socket is not working ~ 3 v on both connections ????

Advise
Thanks

[gyroman]

Just for a reference I copied the following from a tech.

"A fully charged 48 volt battery pack should have 50.93 volts at rest and will drop to around 46-48 volts and slowly come back up as the golf carts start moving faster."

So your pack is dropping down to 45.28v and your #1 battery is a lot lower than the rest.

That's why your slowing on hills. But that set may give you a lot of miles before you need to replace it. The pro's don't recommend replacing just one or two batteries, they say replacing the whole set is the way to go.

[gyroman]

Btw you don't have to do all that to load test batteries. Just hook to each battery one at a time and floor it and record the lowest it drops to before climbing. Same for total pack voltage.

[bigcontender]

0k thanks

I'm going to talk with my local NAPA dealer and see if they will honor the 1 year warentee on these batteries. This set is only 11 months old.

[gyroman]

No problem, see if they will at least replace #1 and #7. If so you should see a big difference.

[bigcontender]

Ok so I replaced batteries 1 and 7 with the same Duracell EGC2 form Sam's club. The voltages on 1 and 7 are better 5.89 and 6.24 on a 6% grade.

The speed is now a min of 8 mph on the 6%10% and 13% grades.
So it seems better.

Thanks for the help

[gyroman]

Well that's a 60% improvement over the 5mph you were getting. And to be fair most all carts slow a good bit going uphill. The only one that I know of that doesn't is BamaBrad's cart after he upgraded to Lithiums

https://www.buggiesgonewild.com/showthread.php?t=167833

Check the above thread starting at post #12

And thanks for the update on your cart!