We put 6 new 8 volt Trojan batteries in ours last year. It was right at $700. You can get cheap batteries for around $500 a set, but everybody said the good batteries were a better buy. The Trojans I replaced were 7 years old and still worked, but the range was short. I drove it probably 16 miles on one trip last week, and still had juice left.

I bought mine with a high speed motor. It has trouble with hills though. I'm going to swap it for a high torque motor as soon as I can come up with the money.