Could someone tell me what the maximum permissible battery voltage for battery packs to be used with the Olympus D-500 is? I have a flashlight, 7.2V Makita, with several of the Ni-Cd re-chargeable batteries. Could one of these batteries be used? Thanks, Tim

-- Tim Cole (tim.cole@aviation.capital.ge.com), October 30, 1998

Answers

7.2v is probably a bit high: The cameras are typically designed to run from 4 AA cells. Alkaline AAs produce 1.5 volts each, for a total of 6 volts. You can doubtless get away with a bit higher, but I'd not want to push it all the way to 7.2 volts. Here's a thought (but don't blame me if it kills your camera! ;-) A silicon diode (plain old garden-variety Radio Shack power diode) drops a pretty consistent 0.6-0.7 volts across it in the "forward" direction. If you connected a diode in series with your battery pack (build it into whatever sort of wiring harness you come up with), you'd end up with a voltage at the camera of about 6.5-6.6 volts, *probably* in the safety range.

Depending on the battery you're using, I don't know that you'll see a gigantic boost in battery life though: High-capacity AA NiMH batteries typically run 1200-1300 mAh, whereas typical 7.2 volt NiCd battery packs are about the same capacity. (Some go as high as 2000 mAh, but for a LOT of money.) My advice? Buy a couple of sets of good-quality NiMH rechargeable AAs for about $10 a set, and a decent charger...

-- Dave Etchells (web@imaging-resource.com), November 02, 1998.