5 Tips to Keep 18650  Li-on Batteries Last Life

We have to say thanks to the inventor of rechargeable batteries that we can reuse our batteries economically and conveniently.

The most popular type is 18650 batteries used in a lot of devices like flashlights (you can findthe best 18650 battery for flashlight here), smoking devices, laptops, and more electronics. Not everybody knows how to use it properly for a longer life. I want to share five ways to extend the 18650 batteries life with you.

Here they are:

The essential rule to keep best 18650 batteries prolonged is increasing the number of cycle life. In case you don’t know what the batteries cycle life is, I will explain it to you.

Being charged and discharged accounts for one cycle. The more cycles your batteries have, the longer they last.

Typically, modern 18650 batteries have around 300 – 500 (charge, discharge cycles). Battery users also need to concern parameters: Capacity (mAh), Discharge Current (A), Charge Current (A).

1. Store the Batteries at the Appropriate Temperature:

We are told to use and keep cells in the range of temperature from 20 to 25 degrees of Celcius. A little lower or higher storage temperature than recommendation can cause a loss in efficacy.

Specifically, according to engineers, every 10 degrees variation will decrease 20-30 mAh of the capacity. The higher deviation leads to the bigger capacity’s loss, the bigger capacity’s loss leads to faster degradation.

However, having said that it’s hard to control the weather, especially in the winter. The only thing we can do to save our batteries is not charging them under the freezing condition. Unless the number of batteries life will drop dramatically and quickly.

In like manner, heat is the dangerous enemy of batteries. It will reduce lithium-ion battery life. Don’t ever charge or leave the 18650 cells near hot places such as inside the car, oven in the kitchen. Don’t let it exceed 60 degrees or else you have to buy a new one soon.

There’re times when we use or charge the batteries, and it is getting hot, please stop using or charging. The cells are trying to tell you that they’re over-stressed.

2. Don’t overcharge (above 4.2V), do undercharge (under 4.0V)


In the charging process, we have to concern two important factors: cycle life and capacity. They are different depending on whether you do a partial charge or a full charge.

A full charge makes the 18650 cells work at full capacity, but at the same time, maybe you are placing a burden on it unintentionally. Thus, it will reduce battery life.

In contrast, a partial charge will maintain or perhaps increase the number of cycle life, though you don’t have the maximum capacity.

You have to choose, cycle life or capacity. For the better, you should charge the li-ion batteries under the voltage 4.0V.

3. Lower the charge current (amps)

Besides the typical conventional chargers, now we have fast chargers by lowering the charge current. It’s about 1 amp or higher.

As two sides of a coin, that type of chargers complete the charging faster but cut the batteries life shorter. Don’t overuse them.

There’s a considerable difference in cycle life between different amp currents. The cycle number for 1.5, 1.0, 0.7, 0.5 amp is about 110, 200, 360, 640 relatively.

Notice the current when charging, because it affects your 18650 batteries a lot.

4. Lower the discharge current (amps)

When discharging, we can decide the cut-off voltage as well as the amperage. Batteries users are recommended to discharge with lower amperage.

The reason is when we use a higher amperage, it will quickly drain away from the batteries. As a result, it will reduce both the capacity and the cycle life at the same time.

We should copy electronic giants like LG, Samsung, Sony, Panasonic. They usually conduct their official tests at 0.5 or 0.8 amps currents.

5. Increase Your Cut-off Voltage

Lithium-ion batteries don’t have the charge memory like NiCad batteries, so there’s no need for deep-discharge cycles.

In way no.2, we’re advised to do a partial charge; so we should do a partial discharge as well. It also means that the battery consumes one partial cycle life. This is a good way to relieve the burden on the 18650 cells, leading to an increase in the number of cycle life. Hence, it prolongs the batteries life.

However, there’re times we should do a full discharge. When?

Batteries experts say that we should discharge fully after about 30 charging times. Because if we keep the partial discharge, chances are causing the “digital memory”, consequently reducing the accuracy of the device power measure. I know we rarely keep track of charging times.

So, after using the batteries for a period of time, letting them drained of energy then recharge it later. This deed helps to recalibrate the power gauge.

If the 18650 cells discharged with the voltage below 2.5V per cell, the battery’s native safety circuit will open, and we may throw the batteries sooner than we expected.

We can’t use the original charger any longer. From now on, you should only discharge to 3,2V for the better.

I know some people want to keep an extra battery for their device and keep it in a fully charged status when it’s not used. If you are one of them, don’t do that. If not, it can’t last as long as the first one.

Because doing that equates to setting the process of lithium-ion oxidation at the highest rate. Instead, you should store the lithium-batteries at 40% discharge, in a refrigerator and absolutely not the freezer.

In conclusion,

Above are the top 5 ways to keep the 18650 batteries last longer. Just pay a little bit of attention, you will save some money from replacing with new cells. I hope this article helpful to you. Share it if it is!