Make every battery last longer

Ten rules for every battery

1. Keep them cool. Heat is the biggest battery killer.
2. Use the charger made for that chemistry.
3. Don't mix old and new, or different brands, in the same device.
4. Take batteries out of devices you store.
5. Don't run rechargeables completely dead.
6. Keep terminals clean and tight.
7. Store lithium partly charged; store lead-acid full.
8. Never charge a battery that is swollen, cracked or hot.
9. Label rechargeables with the date you bought them.
10. Recycle them when they won't hold a charge.

Storage

Cleaning terminals

Lead-acid care

• Recharge right away after use. Sitting partly empty causes sulfation, hard crystals that steal capacity.
• Avoid deep discharge: going below 50% regularly cuts the number of cycles sharply.
• Cold: a fully charged battery won't freeze until far below zero, but a dead one can freeze around 20 °F and crack.
• Float charge stored vehicles with a smart maintainer.

Testing with a multimeter

For a 12.8 V LiFePO4 battery, voltage stays flat at about 13.0 to 13.3 V for most of its charge; use the battery monitor or app instead.

Lithium care

• Phones and laptops last longest kept between about 20% and 80%; many have a "battery health" setting that does this for you.
• Don't leave lithium devices in a hot car.
• LiFePO4: don't charge below 32 °F unless the battery has a built-in heater.
• Use the manufacturer's charger for e-bikes and power tools.

Sources

Checked November 11, 2026.

• Battery University: How to prolong lead-acid batteries
• Battery University: How to prolong lithium-based batteries
• Interstate Batteries: Battery care