Left ON switch on - 2-3 days

[TexasMarci]

Grandson took out key but left ON switch engage the last 2-3 days - cart had been fully charged - the cart would not start up enough to drive 10 feet into garage - it this the reason? or could it have hurt the batteries - I just plugged it in to recharge

[golfcartg]

It likely didn’t destroy the batteries, but it may have taken them down far enough to where the cart doesn’t have the voltage it needs to move. The best way to check is to grab a digital voltmeter, set it to DC volts (usually a 0–200V range if it’s not auto ranging), and check the voltage of each individual battery. Compare each reading to this attached state of charge chart.

Check each battery with a digital voltmeter set to DC volts. For a 36V system (six 6V batteries), you’ll want to see around 6.3-6.4V per battery fully charged after rest, and about 38.2V across the full pack. For a 48V system (six 8V batteries), look for around 8.4-8.5V per battery and 50.9V across the pack when fully charged after rest. If any battery is below 6.0V or 8.0V respectively, it's at a 50% state of charge and considered weak. Next, pressing the pedal while watching voltage will show you how the pack or individual battery holds under load, if the pack dips below 31V (36V system) or 42V (48V system) during load, you’ve likely got a battery or two or weak pack as a whole dragging the system down.

If the batteries are newer, but the pack voltage is too low for the charger to kick on, you may need to charge each battery individually with a 6V or 12V charger just long enough to bring the overall pack voltage high enough for the main charger to take over.