Err...Brum I don't think a solar charger will work too well in a cave <img src="/forums/images/graemlins/blush.gif" alt="" />

OK, I know what you mean but I couldn't help myself <img src="/forums/images/graemlins/smirk.gif" alt="" />

About that charger: Keep in mind that 12 watts is its maximum output under ideal conditions which are different from real world conditions. It may or may not do the job depending on your power requirements. Also its 12V output may or may not be suitable for your needs. Fine if you're charging a 12V battery but lots of equipment is not 12 volts.

I don't know if money is an issue for you or not, but it's not hard to build a very similar device for way less $$$ using thin film solar panels. See my link to Sundance Solar above. All it really takes is some basic soldering skills. Wiring instructions come with the panels.

So simple even a backpacker can do it!!!!