Avg miles per charge?

Ballpark, how many miles do you think I can average using new Trojan T875s and shooting for 60-70% SOC before recharging. My cart is (for now) a stock 2010 TXT 48v. My driving speed is usually 10-12 mph, but I do have some steep hills to drive up and down. If the hills cause to much vagary for the estimate, just leave that out of the equation. Any thoughts or formulas would be appreciated.

Thanks
Mike