The Samsung ATIV S sports a rather large battery, 2300mAh in fact. But what if you wanted some more power to last the day? Mugen Power has answered this desire with a massive 4800mAh extension. The company showcases the product in the above video, which is bundled with a case to accommodate the new battery.
There's a slight bump in the design and the Samsung Windows Phone expands somewhat, but it's a worthwhile trade-off for more than doubling the base charge. The cost of such an increase in power? $89, so be sure to really consider if you'd utilise the extra charge and wouldn't mind having the ATIV S put on some weight (dimensions wise).
Source: Mugen Power Batteries, YouTube; thanks, MBaumi, for the tip!