[Leica] Solar charging of digital camera batteries.

[lrzeitlin at gmail.com (Lawrence Zeitlin)]

Solar charging of digital camera batteries in the field is practical under
certain circumstances. I've been charging similar batteries for use in hand
held GPS navigation units and portable VHF radios in my boat for about ten
years. There are some cautions. Even in bright sunlight, a flat mounted
solar panel will give full charge for only about six hours a day. The panel
must be placed so that no shadow falls on it. Obviously on cloudy days you
are out of luck. The panel voltage should be about 25% higher than the
battery to be charged. Typically individual solar cells produce about .5
volt so a 3.7 v. Leica battery might require a solar panel with 9 solar
cells. Unless you are handy with a soldering iron, this is an odd
configuration. It probably would be better to use a standard 12 v. panel and
charge 3 Leica batteries in series or use a voltage dropping resistor.
Suitable solar panels with a 3 to 5 watt output are sold as charge
maintaining batteries in auto parts stores for less than $100..

In general, unless you are hiking on the Appalachian trail or kayaking in
the Pacific Northwest, it might be better to use a charger that plugs into
your auto cigarette lighter socket. I don't know if Leica makes such a
charger but one came with my Sanyo digital video camera.

Larry Z