convert 36 volt ezgo to 42 volt?

mathisclay said:

I have a 2002 ezgo golf cart that I have the following upgrades:
400 amp controller, high amp forward-reverse, 4 gauge wiring and 6:1 gear ratio rear end.
I can easily run 28 mph but need more power if starting on hills.
My question- Can I add one 6 volt battery to make 42 volts and also will my 36 volt charger work?

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Hi mat,

What you need for improving hill starting capability is more torque. Starting torque for these types of controllers is proportional to the current rating; 400 Amps in your case. Raising the battery voltage will not affect that.

The controller may or may not work with the extra 6 Volts. The charger would not fully charge the pack with the added battery.

I recommend you take a voltage and current measurement on the hill condition to see what is really happening with the battery and at the motor before doing any modifications.

Regards,

major

More thoughts. 42 Volts is an oddball pack voltage. 48V is common in golf carts. In fact, some motor controllers are rated to run at 36/48V, meaning 36 or 48. Using the same motor, 48V will yield higher RPM. Torque would be the same dependent on the current, like 400 Amps.

Now the suggestion to get improved hill starting. Keeping the same motor torque at 400A, change the axle ratio to like 8:1. That should give you 33% more wheel torque over the 6:1. It would also slow the cart speed proportionally. That could be regained by increasing from 36 to 48V.

Chargers are rarely if ever dual voltage, so it would require a 48V charger.

All that for an old cart may not be worth it.

Good luck,

major