MPT 1000E sluggish after continued use

[BlackWater88]

I have a 2007 MPT 1000E 48v with a 6” drop axle lift and 23” tires. I have brand new US2200 batters (8-6v) and a brand new SW200 400a solenoid. All this was installed within 4 days so I haven’t had a ton of time to notice the problem. With that said, when I get on the cart for the first time of the day it is very zippy and responsive and after some use (before my voltage meter even says Iv lost any charge) it tends to stall on semi flat ground. As long as I’m at a constant roll it does okay on slight grades but if i stop I have to back up and point the front end in a direction with less resistance. Any suggestions will be greatly appreciated. I’m not expecting this cart to be a hot rod I just want to be able to reliably throw a sack of feed in the bed and go to the back to feed cows!

On a side note the same problem happened with the stock solenoid. It has the stock motor and stock Curtis PMC SepEx controller.

[JohnnieB]

Attached is a SoC chart for US Battery brand batteries. (SoC voltage is higher than most other brands)

What is the voltage reading about 12 hours after charger shuts off?

What Make/Model charger? (not all of them will fully charge US Battery brand batteries)

[JohnnieB]

Also, new batteries only have about 75% of their rated storage capacity.

It takes about two dozen charge cycles to get anywhere near full capacity and a hundred or so to fully break them in.

[BlackWater88]

Originally Posted by JohnnieB

Attached is a SoC chart for US Battery brand batteries. (SoC voltage is higher than most other brands)

What is the voltage reading about 12 hours after charger shuts off?

What Make/Model charger? (not all of them will fully charge US Battery brand batteries)

JohnnieB the charger is a Lestronic 2 automatic battery charger, the new batteries have had two full charges, it has probably been 16hrs since the last full charge (plus I have rode it around the yard for roughly an hour), individually they are showing 6.31 volts and the pack as a whole is showing 50.56 volts. I will full charge tonight and check in 12hrs if need be. Thank you for the response.

[JohnnieB]

Originally Posted by BlackWater88

JohnnieB the charger is a Lestronic 2 automatic battery charger, the new batteries have had two full charges, it has probably been 16hrs since the last full charge (plus I have rode it around the yard for roughly an hour), individually they are showing 6.31 volts and the pack as a whole is showing 50.56 volts. I will full charge tonight and check in 12hrs if need be. Thank you for the response.

That is 90% SoC after riding around the yard for an hour. Sounds like the batteries are be charged okay, but best to check and be sure.

The 23" tall tires robs your cart of about about 22% of the torque available where rubber meets road and reduces the motor's RPM for any given speed by about 28%, so the motor is drawing more amps than it would with stock height (18") tires and heat increases exponentially while amps increase linearly, so the controller might be going into a reduced performance mode due top overheating.

Also, the stock cables might be a bit on the thin side for the higher amp flow. All 12 ought to be 4Ga or thicker. Are any cables getting more than 10°F above ambient?

Here's a service manual.

[BlackWater88]

Originally Posted by JohnnieB

That is 90% SoC after riding around the yard for an hour. Sounds like the batteries are be charged okay, but best to check and be sure.

The 23" tall tires robs your cart of about about 22% of the torque available where rubber meets road and reduces the motor's RPM for any given speed by about 28%, so the motor is drawing more amps than it would with stock height (18") tires and heat increases exponentially while amps increase linearly, so the controller might be going into a reduced performance mode due top overheating.

Also, the stock cables might be a bit on the thin side for the higher amp flow. All 12 ought to be 4Ga or thicker. Are any cables getting more than 10°F above ambient?

Here's a service manual.

So batteries are good, cables are 4Ga, I’ll have to check the temp tomorrow, I did notice today that my controller (Curtis PMC SepEx 1264 I believe) on the status light showed a 2-3 according to the cart that is on the cart is Thermal Cutback - allow controller to cool. It still shows this code even hours after use. I took it apon myself to disassemble the motor and cleaned it. After blowing all the carbon dust out it hasn’t stalled since my be a coincidence being as tho I have the 2-3 code, thank you for the replies JohnnnieB I am a newbie to this.