In reply to SenzuBean:
Even with a solar powered battery, the battery still needs to be replaced, just not so often. One of mine lasted less than 5 years and you get 3 years out of a normal casio IMHO. So the case for spending more on solar power is not so good.
It might be worth waiting for the Suunto Indoor Vector which is aimed at the indoor mountaineering market, it will tell you what height you've reached, whether you've pulled on the wrong colour holds and also has an accelerometer to record an rope rests.