By Claire Gillespie
Updated Mar 24, 2022
Lithium‑ion batteries, often called Li‑on cells, are the preferred choice for modern electronics—from laptops to handheld camcorders—because they offer higher capacity, lower self‑discharge, and a greater number of charge cycles than Ni‑Cad or Ni‑MH alternatives. Before you toss a battery that seems dead, give it one last chance to return to life.
Power off the device, remove the battery, and measure its voltage. If the rated voltage is 3.7 V but the meter reads only 1.5 V, the cell may have entered a sleep state due to deep discharge.
Insert the battery into a charger that supports a wake‑up or recovery function. Align the polarity correctly and let the charger attempt to revive the cell. Success is not guaranteed, especially if the battery has sat below 1.5 V for more than a week, but many batteries respond to this step.
Within about a minute of initiating recovery, re-check the voltage. Some chargers will indicate when the process is complete. If the voltage still shows a significant drop, the battery may be beyond recovery.
Place the battery back in the charger and allow a full charge—typically around three hours, depending on the cell type. Once fully charged, discharge it in a device that draws a heavy load, such as an LED flashlight, to confirm that the battery now supplies adequate power.
Seal the battery in an airtight bag and store it in a freezer for about 24 hours, ensuring no moisture enters the bag. After removal, let it thaw at room temperature for up to eight hours before re‑charging.
Charge the battery to full again. A successful revival will often result in improved capacity and a longer interval between full charges.
• Store Li‑ion cells at room temperature or cooler.
• Charge a discharged battery promptly.
• Regularly charge, even if not fully depleted, to extend lifespan.
The electrolyte inside a Li‑ion battery is flammable, and the cell is pressurised. Always wear safety glasses and handle batteries with care.
