How many times have you picked up your digital camera to catch some fleeting scene and ended up with a low battery warning? It happened to us far too often. We refuse to use disposable alkaline or lithium batteries, so the options become pretty limited. Most of the disposables have a voltage of 1.5 volts or higher and most cameras use either two or four batteries, usually “AA” size. The Ni-MH (nickel metal hydride) rechargeable batteries commonly available top out at about 1.2 volts, and that drops off at about 15% per month or more, so they work best only immediately after charging. This isn’t great when you want something ready NOW. Lithium batteries, on the other hand, only self-discharge at about 1% per month. We ended up purchasing these “14500” lithium rechargeable cells from Amazon.com, along with some “dummy cells” from Radio Shack (in metric notation “14500” converts to 14mm diameter and 500mm length, the same as a “AA” cell).
If you search for 14500 size lithium rechargeable batteries on the Web you will readily find a few companies that sell these, and the appropriate charger. This one is from Nitecore, model i4, capable of charging both Ni-MH and lithium batteries from either 120-volt AC or 12-volt DC sources, from tiny AAA size up to “26650” lithium (giant 5 amp-hour) cells.
The rechargeable lithiums are full at about 4.15 volts, while “normal” AA batteries are full at 1.5 to 1.6 volts, so the fake batteries simply pass power through without affecting voltage. If your camera normally uses two AA cells, you simply insert one lithium battery and one dummy cell. If it uses four cells you use two batteries and two dummy cells. The camera always sees a super-full battery and stays full of charge seemingly forever. Works great, and no more missed photos!