Power is supplied by an internal rechargeable battery (lithium-ion prismatic cell), by an external voltage, or through the USB host.

电力由内部充电电池（圆柱形锂电池）、外接电源或 USB 主机提供。

youdao

For one, it's not clear how long the two-cell lithium ion battery will last, and pricing or availability are missing from the brochure (at the source link).

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As part of their investigation, Japanese and U.S. experts want to determine if an internal battery failure, or defective lithium-ion cell, was the ignition source in either of the two incidents.

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