Portable cell phone charger

I've field-tested a portable charger (that used 4x AAA batteries) and weighed 67g complete (25g w/o batteries).

2 sets of alkaline batteries were required to fully charge the phone, one set got it about halfway.

In contrast a spare phone battery is around 20g and a mains charger is around 65g.

For my next long trip I haven't yet decided how best to resolve phone battery power – I use a camerphone.

Energizer makes one that uses two AA batteries.

A person who modified…
“These are great. I modified the cable on mine so that instead of a male mini usb port, it’s a female USB A port. I use it to charge anything and everything that can charge off of USB with the help of a Ziplinq retractable cable. Phones, Nintendo DS, weather radio, etc.”