Solar, Generator or ?

[icanon]

Next year I am planning a few days of 'off grid' camping to do some astronomy. Usually I go to star parties with full hook-up but planning on doing some solo in some nat'l parks.

My question is what is a cost effective way to recharge my battery while I'm off grid? Should I go solar, generator or just add another battery? I will need a minimal of power to run the detectors, propane fridge and an hour per day of water pump all of this will be off grid for 4 days max.

So what would you do? Remember I am planning to do this once or twice per summer.

Thanks.

[2oldman]

Extra battery. An hour/day of water pump seems excessive.