Questions about Sony LIP-4WM replacement battery for Minidisc players

This item is new. The playback time depends on the player you're actually going to use it with. If you replace this battery for the same battery you already had, you can except about the same usage.

Probably not. According to the instructions, it needs a "LIP-8" battery: Sony LIP-8, Rech. Lith. Ion Battery Current delivery time: 2-4 weeks (no stock at supplier)