Devices such as Google Glass and Nexus 7 may be fun to use but their battery does not last you forever. It is frustrating to run out of battery juice when you really need your gadget. The System-S Backup Battery Charger Extender is a handy emergency charger that lets you use 4 AA batteries to recharge your gadgets. It provides hours of battery for your devices. The charger is compact and slim.
We tested this AA Battery Extender to charge Google Glass, Kindle, and Nexus 7. It simply works as long as you provide it with 4 decent AA batteries. Not too expensive either.