I had an old digital camera that took 4 AA cells, and was apparently designed for alkalines to get 4 x 1.5 = 6 volts. But with 4 x 1.2V rechargeables it only got 4.8V right at the start, and went downhill from there. I kept thinking about ways to add a holder for a 5th battery to get 5 x 1.2 = 6V, but the camera died a permanent death before I got around to it.
Best regards,
Bob Masta DAQARTA v6.00 Data AcQuisition And Real-Time Analysis