This isn't an additional "add-on" battery, this is just an extra internal battery, so if you're on a long fight, or on the train and your battery's low, you can just take the other one out, and put this on in it's place. So essentially it's only the battery that comes with the h1910. Sorry to burst your bubble, but there aren't any external batteries for the h19xx series. There's no support for it. Although, You can look for external chargers, you can find a bunch here:
http://www.data-nation.com/main.htm