Hi, I'm headed out to a 10 day long trip later this summer where I won't be able to charge my M240 battery using usual methods - I won't have access to external power sources at all. I will take some spare batteries (http://us.renesola.com//) but it would be tragic if I ran out of juice.
The standard charger does have a 12 v car adapter socket, I wondered if anyone has successfully used a solar charger for this?
If you are referring to a Leica camera battery, then if you build or buy an appropriate CI/CV circuit, you could use any of the Goal Zero or similar solar panels to charge it. The M240 current limit should be set to 1.8A maximum. A lower value will work, but will of course take longer to charge. The voltage limit should be set to 8.4V.