A standard lithium ion 18650 battery is rated to last between 300 to 500 cycles before noticing a large performance drop. That is a pretty wide range and we’ll discuss some things you can do to extend your batteries life to 500 or even more cycles.
When we say charge cycle, this means charging the battery to 4.1V – 4.2V and discharging to 2.5V – 3.0V. When your battery begins to age, you will notice diminished capacity slowly over time. When your cell is nearing the end of its life cycle, the performance will drop suddenly and fast.
Some things that can alter the life range of your battery:
- Temperature – 18650 batteries age at an accelerated rate below 0o C or above 45o . You should never charge or use your batteries when the temperature is outside of this range as it could severely damage the life of the battery. Also, running your batteries hard causing the internal temperature to rise near or above 45o C can also reduce the life of your battery.
- Discharging/ Charging – If you can avoid discharging your batteries below 3.0V and not all the way down to 2.5V, this can really help to extend the life of your battery. The same is true when charging your battery. Avoid charging your battery above 4.1V. Keeping your battery in this healthy range very much reduces the stress on the battery causing it’s life to nearly double. Again, try to keep your battery within the range of 3.0V to 4.1V.
- Charger – Make sure your charging device turns off when the battery has finished charging and remove your batteries from the device when charging is complete. The reason to remove batteries from the charging device is batteries naturally lose energy over time and the charger will notice the drop and turn back on to top off the battery. This constant on/off charging can really diminish the life of your battery.
- Charge just before use – When you charge a cell to 4.2V and keep it on standby for multiple days, this puts stress on the battery. It’s best to store your 18650 batteries in a discharged state if you don’t plan on using them right away.
- Charge Rate – Some chargers now on the market are rated to charge at 4A or even 6A. Keep in mind this rapid charging can be convenient but can also severly diminish the life of your battery. A healthy range to charge your batteries at is anywhere between 0.5A and 2A.
Once your battery life cycle has ended, we highly advise you to recycle it to help protect our environment. For information on a recycling location near you, please visit https://www.call2recycle.org/