Hearing Aids, Watch Batteies, Coin cell, Lithium Batteries.

助听器，手表电池，硬币状电池，锂电池。

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It is an inflatable pouch that has a thin-film solar panel with two-coin cell rechargeable batteries.

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Get some colored LEDs, coin cell batteries and magnets (kits are available online).

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Bluetooth low energy runs off a small coin cell battery, lasts about a year, and allows a small tag to send data to a phone.

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