rechargeable battery; secondary battery
Technical term used in electronics and engineering; contrasts with 一次電池 (primary battery).
Lithium-ion rechargeable batteries are used in smartphones.
Secondary batteries can be recharged repeatedly.
二次電池 is the precise technical term for a rechargeable battery, essentially interchangeable with 蓄電池 in engineering contexts.
Compound of 二次 (secondary) and 電池 (battery), a calque of the English term 'secondary battery'.