Haha no I wasn't confused! It was a genuine question because I'm looking for a sensible source of energy for a robot arm. 7.6V made just as much sense to me as 8.5 or 6.3 or any other random pair of digits!
IIRC, the common lithium cell in a lot of batteries delivers 3.7 volts. So if internally the battery has 2 cells in parallel, it would deliver 7.4 volts (11.1 volts if the battery has 3 cells in parallel). Nimh batteries like AA rechargeables tend to deliver 1.2 volts, so 3 AA rechargeable batteries would be 3.6 volts, 6 would be 7.2 volts, etc.
Of course batteries often times deliver voltage in a range, rather than being a specific value.