Voltage Drop, Slow Rolling

[hayn_superman]

Hey Everyone, I'm somewhat new to posting but have been following the forum for the past months now. I have an 02 DS (AQ) and over this Thanksgiving my wife and I Just recently did a quick project and stripped the cart and gave it a 6 inch GTW lift on 23 inch tires.

After everything was bolted back on we took it for a test drive and I noticed that the cart went faster but the voltage was taking a drastic drop.

I have a speed magnet and also a Voltage Digital Meter. Battery reads 50.4v but after driving batteries drop down to as low as 32v. I noticed when I fully press and floor the pedal is when the voltage drops to 30s. Halfway pressed keeps me in the ~40v range. After the test drive I could not even make it up my steep driveway I needed to push it back into my garage.

I don't have a date stamp on the batteries but they are US batts possibly around 2 years old.

Main reason for this post is to find out what could be the problem? Bad controller? Just need new batteries? Speed sensor? Any info would be greatly appreciated.

[movin-on]

Sounds like batteries...On a 48v cart the pack voltage shouldn't drop below 42v under load...To take it further, put your meter on each battery and floor it for 100 ft or so...Any battery that drops below 7v is bad...I believe on US batteries the date stamp is on the negative terminal like Trojans...Should be a letter (month) and a number (date)..

[hayn_superman]

@Movin-on. Thank you I tried load testing them last night but that was literally right off the charger so not sure if that would mess with the readings. I’ll try again after work today.

When I did test last night I jacked up the rear of the cart and most batteries read a little over 8v while pressing the gas. There was one battery that read 7.5v.

I need to look at the stamps. But definitely want to get new batteries. What’s common battery life?

[movin-on]

You have to have the cart on the ground and running to get a good load test...You can burn up the motor with the cart jacked up and running so be careful...
5 years give or take is the average life of deep cycle batteries depending on the quality and how they are taken care of..I've seen some last 3yrs and some last 8yrs..

[hayn_superman]

Thank you. Yeah I wasn’t trying to press the throttle for a long duration just enough to get a volt reading. But will definitely try load test while rolling