How to Store Lithium Batteries?

Storing lithium batteries safely is mostly about temperature, state of charge, and preventing short-circuits. Here are practical guidelines that work for most common types (Li-ion, Li-polymer, LiFePO₄).

The essentials

• Store cool, dry, and stable: ideally 15–25°C (59–77°F). Avoid direct sun, heaters, cars in summer, and freezing conditions.
• Store partly charged (not full, not empty):
  • Li-ion / Li-polymer: around 40–60% charge (often ~3.7–3.9V per cell).
  • LiFePO₄ (LFP): about 40–60% as well (often ~3.2–3.3V per cell).
• Prevent short circuits: keep terminals covered; don’t store loose cells where they can touch metal objects (coins, tools, etc.).
• Use a non-flammable storage setup:
  • Best: metal ammo box (unsealed), metal cabinet, or a LiPo safety bag for small packs.
  • Keep away from paper, fabrics, solvents, gasoline, etc.

Long-term storage (weeks to months)

• Check every 2–3 months:
  • Recharge back to ~50% if it has dropped a lot.
  • If a pack is swelling, hot, leaking, or damaged → stop using and dispose safely.
• Don’t store fully depleted: letting voltage fall too low can permanently damage cells and increase risk.
• Avoid “trickle charging” in storage: charge to the storage level, then disconnect.

Where to store

• Good: closet shelf in a cool room, metal cabinet, dedicated battery drawer with insulation, garage only if it stays moderate.
• Avoid: hot garages/attics, near ovens/radiators, in cars, humid basements, direct sunlight.

Different battery formats

Small consumer cells (18650/21700, power-tool packs, camera batteries)

• Keep in plastic cases or original packaging.
• Don’t stack loose cells in a drawer.

RC / drone LiPo packs

• Use “Storage mode” on the charger.
• Store in a LiPo bag and preferably inside a metal container on a non-flammable surface.

Large batteries (e-bike, solar, UPS, marine packs)

• Turn the pack off (if it has a switch) and store around 40–60% SOC.
• Keep them upright, ventilated, away from combustibles.
• If it’s a system battery, ensure the BMS is functioning; some packs have a sleep mode you want enabled.

Safety red flags (don’t ignore)

• Swelling, hissing, odd smell, leaking, hot to touch, cracked casing, or corroded terminals → isolate it in a non-flammable area and follow local disposal guidance.

Quick checklist

• ✅ 40–60% charged
• ✅ 15–25°C, dry
• ✅ terminals protected
• ✅ non-flammable container/location
• ✅ inspect every few months