I cant make it stay running!

[Bentley Meredith]

I have a 2011 Electric Yamaha YDREX,. I bought it just over 2 years ago, and other then a minor issue with terminal corrosion a few months back, it has been a good buy. The problem is the unit will run, but very slowly, you have to barely touch the pedal, if you smash it, it just quits. If you let off the pedal, it makes 2 clicks, and you can start the process again. I have a multi-meter?, I really dont know how to use it, I set it on the DCV 20 and I put the red lead in the bottom right and the black in the one above that.

The cart has 6 batteries, so the little I know I assume it is a 48 volt cart. This may be laughable, but I assume that each puts out (or should) 8 volts? Testing them they are 9.1, 9.6, 9.7, 8.5, 8.8 and 8.5. I saw on here someone talking about total (I cant remember what they called it) and I have no idea how you read that, I guess you have some thing on your cart that does that, that I do not have.

I dont like taking stuff to shops if I dont have to, but I would in a NY Minute on this go round, I have no idea what I am doing. Mayberry just does not have any shops, well they have one, but I dont trust them and simply do not want to do business with them.

So I though I would throw my issue out there. If I thought it was simply a matter of replacing batteries, I would do it...it would be costly, but I could do it. I just hate to replace 6 batteries and it does not fix the issue. I realize it is almost impossible to help someone in a situation like this! I just though if the symptoms were something others had experienced, they could point me in a direction. Thanks for reading, and if you can help, it would be appreciated!

And while I have your ear, incase it is a battery issue, can anyone recommend a quality battery that will last that will not break the bank?

[golfcartg]

You’ve already checked the resting voltages for each battery and those numbers tell us a lot. You mentioned that the voltages range from 8.5V to 9.7V. While those aren’t terrible readings, resting voltage alone doesn’t tell the full story. A battery could show decent voltage but still fail under load, which is likely what’s happening here given the symptoms you're describing.

Now it’s time to perform an individual load test to get a clearer picture of each battery’s health. To do this, you’ll want to use a load tester. First, charge up and label the batteries so you can track which readings correspond to which battery. Then, let the batteries rest for a few hours and disconnect each battery one at a time and attach the load tester. The goal is to see how the battery performs under a simulated working condition. A good battery should maintain around 7.5-8V under load for several seconds without dropping too much. If a battery drops well below that, say, to 7V or lower, it’s a sign that the battery is weak and might be the cause of the slow performance you’ve described. See the attached chart for reference. Ideally, you never want your lead acid batteries to fall below a 50% state of charge when measuring resting voltage. When the voltage hovers below this level it can cause sulfation, which permanently reduces the battery's capacity and lifespan. Always keeping the charge above 50% provides optimal performance.

Back to the issues you’re seeing with the cart, it’s possible that when you press the pedal hard, those weaker batteries can’t keep up with the demand for power, causing the cart to cut out. The fact that it runs better with light pedal pressure suggests that it’s able to draw just enough power under lighter loads, but struggles when more power is needed. By conducting a load test on each battery, we’ll be able to pinpoint which batteries (if any) are underperforming and causing this issue. If you have any questions feel free to ask!