Sudden voltage drop and squeaking noise during acceleration

[christopher425]

Hey Everyone! I’ve got a 2001 Yamaha G16 36volt with a series drive. If I floor the accelerator pedal I will get this high pitched squealing/squeaking sound and my voltage will drop suddenly with my speed being greatly reduced. It will pick back up steadily (voltage & speed) on its own, especially if I let off the pedal to let it ‘catch up.’ It honestly sounds like a belt slipping, but I know there’s no belt. Sometimes at random it will have short episodes where it will happen for like a second or two while at cruising speed. I most notice it accelerating from a dead start, but it doesn’t happen every time.
I’ve got brand new batteries that have less than a month of use on them and the voltage readouts are good for each battery. I upgraded my battery cables to 4g, but have yet to upgrade all of my stock wiring to controller, motor, etc. I’ve searched through threads and found similar issue by other folks, but never a clear answer or resolution (I.e. splines, water in pedal box, etc). Cart runs great. Just had this intermittent issue. Any help is appreciated. Thanks y’all!

[christopher425]

Anyone have input on this?