Meh, it's only 1600mah. You'd be better off with a Tekkeon mp1550 and a set of 2500mah NiMH rechargeables. That'll give you 5000mah of operating time and will easily take your NIT to a full charge from dead.

The general rule of charging I've learned is that you need 2.5 x total MAH of your battery to charge it full from dead. So if your battery is 1600mah, you'll need 4000mah minimum to fully charge it. If the device is running, you'll need an extra 20% more power to fully charge it since the device will consume part of that power.

And that rule doesn't necessarily apply to all devices, as with some it's as low as 1.5x and some are as high as 4x, but the general rule of thumb is 2.5x for most devices.

You can check out the Tekkeon 1550 here: http://tekkeon.com/products-tekcharge1550.html

I've got one and love it to death!