Amazon is not bad but i'll recommend wagawoo hear from my friends, for this those are famous for all kind of battery chargers like Industrial chargers, marine chargers, lithium packs and many more.
I tried this one posted on Amazon.
TimeTec 2 x 1800mAh Li-ion Batteries For Motorola Atrix 4G, ME860, MB860; Fits BH6X + Free Bonus TimeTec Multi-purpose USB Travel Charger
It's a combo pack, two 1800mAh battery with an external charger. Charging is fast. So it called travel charger. I just spent 20 something, so far so good since Nov. 2012. Share with you.
The first thing you need to address when selecting your external electric electric battery power is to select a charger that delivers at smallest the identical or greater yield in volts. The storage capability is significant because it determines not only how much of a ascribe the power pack can shop, but how much it power it can send out before it furthermore desires recharging.
Amazon is okay but try to use Ebay as well because I've seen so many portable external batter charger there. It's very uncommon if you can't find any there, in case not there are some computer stores near you which can help you.
I am looking for an external battery charger. I see a company called RAVpower is a vendor on DF. Has anyone tried this one Amazon.com: RAVPower Deluxe External Battery Charger 14000mAh Portable Power Bank Pack for iPhone 5S,5C,5 (Lightning Cable not included), 4S, 4, iPad Air, iPad 4, 3, 2, Mini 2, Mini, iPods; Samsung Galaxy S4, S3, S2, Note 3 Note 2; Nexus 7, Nexus 5,
Droid does some cool and amazing things. Yet it does not do some basic stuff that has been stock on most phones for years. It makes me think the Google developers were marooned in some kind of a 1977 LOST flashback/flashforward/sideways combo reality gameshow