I bought a larger battery

[wolong]

I was very frustrated with how fast the battery would discharge on my VS920 Spectrum. Anyway, I saw that eBay offers a bigger, high capacity, inexpensive battery for the Spectrum, along with a special cover that enables the thicker battery to be used. I LOVE IT. Works great. This is a MUST accessory for the Spectrum! My spectrum is now a bit thicker but I actually like the feel better.

 

[Rukbat]

I prefer two batteries. Run one down to 40% and, if I can't charge it, swap them. That gives me twice the capacity of one battery, the same thickness (in case it matters, like for a case) and a high-quality normal capacity battery is usually cheaper than even a cheap higher-capacity battery.

But now, buy a cheap universal charger (they're available for under $10 - I use this one) and keep the original battery charged and in your pocket (in a plastic bag or, if the larg one came in a soft plastic case, that case, so it won't get shorted by money or keys) and you'll have a spare. Even if you don't need it, once a month, put it in and use it until it's down to 40%, then put the big one back in and charge the spare. One day, when you're down to "get to a charger fast" time with the larger battery, you'll have the spare in your pocket.

(And if you want the batteries to last, never drop them below 40% if possible. See The Care and Feeding of Lithium Polymer Batteries.)