[Yosemitest]

I've been researching the GPS devices and the digital watches with altimeter and barometer.
I like the digital watches, but not the GPS watches because of short battery life.
The I-phone and the I-pad both can take an APP that is a GPS Altimeter that doesn't drain the battery near as fast, IF you use it off and on.
But if you leave the altimeter GPS function on all the time, it drains the battery pretty fast.
Research SpyGlass, and "Exact Altimeter for iPad by BitKnights"

[semimojo]

Hiked the JMT last summer with a few USB chargeable devices. There are some pretty good solar options out there that won’t weigh you down.