Battery self-discharge is the loss of charge in open circuit due to electrolyte decomposition, SEI layer formation, and interface side reactions, influenced by battery type and temperature. LiFePO₄: <1%; Li-ion: 1–2%. Best storage: 40–60% charge, low temperature, good ventilation to slow self-discharge.

This article systematically introduces the impact of power tool battery type (Li‑ion, NiCd, NiMH), voltage (12V, 18V, 20V and above), compatibility and capacity on tool performance and battery life, and helps you make a wise choice based on your own needs through comparison and FAQs.