Mondpalast ® Dual Dock Charger + 2 x high quality 2800mAh Battery for Samsung i9300 Galaxy S3 SIII i9305 GT-i9300 (Electronics)
If charger and two batteries is really extra, batteries are at their full capacity after three loading, plus it is more efficient than the original battery (Samsung) who stood barely twenty hours while the lasts about thirty six hours