Japan Trust Technology have improved and extended the battery life on the Nintendo 3DS by up to 10 hours play time with their new expanded battery device.
It was released today in Japan and gives your 3DS 800mAh, 4.4 times the system’s standard battery. The 3DS does become 9mm thicker, but the investment is worth it, if you consider it gives you all those extra hours of battery life.
The battery is available in two sets; one white with red and pink covers for ¥9,980 and one blue with black covers for ¥9,480. The product page shows ordering instructions and a picture demonstration on how to swap out the battery.