In , wrote:
TheHack wrote:

http://www.dewalt.com/tools/cordless...hts-dc527.aspx
run time:3.5 hrs

Dewalt makes a larger light with 1.5 hrs of run time that uses the same
battery system.

ok crazy idea

but how could I charge these battery packs using solar
panel? say for remote cabin ... off grid

If your battery is Li ion, use a charging circuit that incorporates an
IC made for that purpose. And make sure you use a power supply such
that the IC does not malfunction. (Preferably with "linear" rather than
"switching" regulation if your power supply is a solar cell array or
similarly short of "rock solid"). Li ion batteries are fussy about being
overcharged, and their hazards increase significantly if they are
overcharged.

--
- Don Klipstein )