The phrase "additional battery" is correct and usable in written English.
It can be used when referring to an extra battery that can be used to extend the power supply of a device.
Example: "I always carry an additional battery with me when I travel to ensure my devices stay charged."
Alternatives: "extra battery" or "spare battery".
Additional battery projects, and potential projects, are sprinkled around Texas.
He expects to be able to fly it for around 40 minutes, and longer with additional battery packs.
A more ambitious alternative is the plug-in hybrid, which contains an additional battery and can be plugged in to get the charge as high as possible.
"Some phones use an additional battery for memory management; it's unclear whether this battery could be used by logging and/or tracking systems such as Carrier IQ," Mr. Harvey explained, referring to software that monitors mobile phone users.
Mr. Barak spoke at an Israeli military industrial plant in the southern city of Ashdod, telling his hosts that an additional battery of a new antirocket defense system would be set up soon to intercept rockets fired from Gaza.
Consumers are demanding a lot from their phone accessories these days, especially additional battery power.
Many deliverymen carry additional batteries with them.
The company says that it will offer additional batteries for $5.
Taiwan is requesting additional batteries of the improved Patriots to extend its protective blanket over the rest of the island.
The technology is eagerly awaited by energy experts and environmentalists, but is not yet ready to go commercial because the additional batteries are not yet durable enough.
Sanyo Xacti HD-1000 video camera (about $700), which shoots at a magnificent 1080i resolution; it's the size of a small revolver, but with extra lenses, microphones, tripod and additional batteries, it actually takes up quite a bit of space.
