Operation of Li-Ion batteries

Tips for using Li-Ion batteries:

Li-Ion batteries are not as «finicky» as their nickel-metal hydride counterparts, but still require some maintenance. By following five simple rules, you can not only extend the life cycle of lithium-ion rechargeable batteries, but also increase the operating time of the flashlight without recharging.

Avoid complete discharge. Lithium-ion batteries have no so-called memory effect, so they can and, moreover, should be charged without waiting for discharge to zero. Many manufacturers calculate the life of a Li-Ion battery by the number of full discharge cycles (to 0%). For quality batteries, this is 400-600 cycles. To increase the life of your Li-Ion battery, charge your flashlight more often. Optimally, as soon as the flashlight announces a low discharge, you can put the flashlight on charge. This will increase the number of discharge cycles to 1000-1100. 

This process is described by experts as Depth Of Discharge. If your flashlight is discharged to 20%, the Depth Of Discharge is 80%. The table below shows the dependence of the number of discharge cycles of a lithium-ion battery on the Depth Of Discharge:

Discharge once every 3 months. A full charge over a long period of time is just as harmful to Li-Ion batteries as a constant discharge to zero. Experts recommend discharging the battery completely once every 3 months and then charging it to 100% and keeping it charged for 8-12 hours. This helps reset the so-called upper and lower battery charge flags.

Store partially charged. The optimal state for long-term storage of a lithium-ion battery is a charge level of 30 to 50 percent at 15°C. If the battery is left fully charged, however, its capacity will decrease significantly over time. But a battery that has been sitting on the shelf for a long time, discharged to zero, is probably dead - it's time to send it to the recycling center. The table below shows how much capacity remains in a Li-Ion battery depending on storage temperature and charge level when stored for 1 year.

Do not overheat. Well, the worst enemy of lithium-ion batteries is high temperature - they can't stand overheating. Therefore, do not allow the flashlight to be exposed to direct sunlight, and do not leave it in close proximity to heat sources, such as electric heaters. The maximum permissible temperatures at which lithium-ion batteries can be used are from -40°C to +50°C.