Simply hooking the radio power to two batteries on your EZGO Golf Cart is not the best way to go.
Your EZ-GO cart will need a converter from 48 or 36-volt to 12-volt for the radio. That way it draws power off of all the batteries equally or eventually your golf cart will not run correctly since one or two batteries will be dead. None of your golf carts batteries will charge properly until those batteries are individually charged to match the others.
Another way to go is to add an extra 12volt Deep-Cycle Marine Battery ( my personal favorite way.). Most carts have room to add one on the driver’s side and you can wire your radio and also lights to it and it will save your cart’s batteries. Just hook your extra battery up for charge when you plug in your cart overnight.