You could also use higher AH capacity 8V batteries to get more range. Not as much as you can get from a 8X6V pack, but more than a 6X8V-170AH pack.
Here are charts showing the kWh storage for various 48V packs using Trojan brand batteries and the weight of various 48V packs. Calculated by the same method, a standard 36V pack using T-105 batteries is 8.6kWh.
I wanted everything to fit under the seat, but wanted more range than I could get from a 6X8V pack using the highest AH 8V batteries available and went with a 7X6V 42V - 245AH pack for 10.9kWh of storage, which gave me a 30+ mile range. Of course, my cart is extremely efficient and I don't haul heavy stuff or carry many passengers.
