Rechargeable Dsi battery and charger kit

850 mAh Battery and charger Kit of DSi for you
comes with 850mAh rechargeable battery and a mini screwdriver. The
original battery for DSi can be replaced by this in case yours is weak
or dead. Battery charger can keep your battery work longer. The DSi
battery and charger are a perfect combination for getting the extra
power needed for long periods of play. [More batteries & chargers]

Features:

1. Battery charger for Nintendo DSi.

2. 850 mAh Rechargeable Battery for Nintendo DSi.

3. Get more fan with this emergency battery.

4. Charge your Nintendo DSi and DSi battery convenient.

5. Battery: Voltage: 3.7V; Capacity: 850 mAh; Battery: Rechargeable Lithium

Source: http://www.gameyeeeah.com/products/Rechargeable-Dsi-battery-and-charger-kit-p-1612.html