NiMH is a kind of battery you can charge again and again. The letters mean nickel-metal hydride: nickel is a metal, and hydride means hydrogen is packed into another metal inside the cell.

NiMH is a kind of batteryNiMH是一種電池 you can charge again and again可以一直反覆充電 The letters mean nickel-metal hydride這幾個字母代表nickel-metal hydride（鎳氫化合物） nickel is a metalnickel是一種金屬（鎳） and hydride means hydrogen is packed into another metal inside the cellhydride則是指電池裡氫被包進另一種金屬裡

For years these were the usual rechargeable AA and AAA batteries in cameras, torches, toys, and small gadgets. Some older hybrid cars used big NiMH packs too.

For years these were the usual rechargeable AA and AAA batteries多年來，這是常見的可充電3號、4號電池 in cameras, torches, toys, and small gadgets用在相機、手電筒、玩具和小型裝置裡 Some older hybrid cars used big NiMH packs too有些較舊的油電混合車也用大型的NiMH電池組

They replaced an older cousin, NiCd (nickel-cadmium), which used a nastier metal. Though actually, many new phones and cars have moved to lithium batteries, which are lighter.

They replaced an older cousin, NiCd (nickel-cadmium)它們取代了較舊的親戚NiCd（鎳鎘電池） which used a nastier metal那種電池用的是更糟糕的金屬 Though actually, many new phones and cars have moved to lithium batteries不過其實現在很多新手機和新車都改用鋰電池了 which are lighter鋰電池比較輕

You still buy NiMH cells for household things you already own. People say the letters slowly, or just “nim.”

You still buy NiMH cells for household things you already own你還是會為了家裡已經有的東西去買NiMH電池 People say the letters slowly有人會把這幾個字母一個一個慢慢念 or just "nim."或直接說『nim』