08 presidentual electrical nightmare

[Bartman357]

My father has a 2008 president 48v and powerdrive II charger.
he was driving it a few hundred yards from his house when it quit.the voltmeter dropped to as low as 8v, so he thought the batteries needed charged! He pulled it home and plugged it in, the charger needle didn't move or hum, but the voltmeter on the dash went up to as high as 70v, but was very sporadic so he unplugged the charger from the cart. The indash voltmeter showed around 47 v, he put it in reverse and the buzzer sounded! He stepped on the accelerator, the cart tried to move and the voltage dropped as low as 8v! Release the pedal, slowly rises back to near 48v!

WHERE DO I START????

[Sergio]

You have one or more bad batteries.

The slowly rising of voltage is typical due to "surface charge" of the cell plates.

The crazy voltage readings are caused by a bad cell suddenly going into high resistance and the meter proving a current path for the charger.

Lift one of the rear wheels.

Measure each battery voltage individually as you press the pedal.

You need to put a load on the batteries for the test or You are just reading the "surface charge" which can be misleading.

[Volt_Ampere]

Could also be a bad connection but I agree it's probably a defective battery.

[Bartman357]

Thanks sergio,
4 new batteries did the trick. $730.00 later, maybe my father will hook the charger up a little more now.
thanks again,
Bartman357