Amazon.com: Gomadic Portable AA Battery Pack Designed for The Garmin etrex 10 20 30 - Powered by 4 X AA Batteries to Provide Emergency Charge. Built Using TipExchange Technology : Electronics
Portable Emergency AA Battery Charger Extender suitable for the Garmin EDGE 510 - with Gomadic Brand TipExchange Technology
Garmin Charge Power Pack, External Battery Pack | eBay
Garmin Edge® 1030 Plus | Cycling Computer with GPS