18650 Battery and Charger-Charging and Making

APR 01, 2020   Pageview:141

An 18650 is a type of rechargeable lithium-ion battery. This cell is mainly classified by its size, which is 18mm x 65mm. The 18650 lithium-ion battery is a bit bigger in size than the AA battery. These cells are mostly used in electronic devices such as laptops, high drain devices, and flashlights.

This kind of battery is extremely powerful and has excellent discharge rates.  That’s why they are mostly preferred for high-end devices. These types of cells often boast of having 300-500 charge cycles, and they come in both flat and button top styles.

The proper way to call this battery is “18650 cell”. It has a voltage of 3.7v and Mili-amp-hours ranging between 1800mAh and 3500mAh.  This 18650 cell can be categorized into two. I.e. protected and unprotected.  The difference between these two categories is that a protected cell features a small integrated circuit inside while the unprotected battery does not.

The protected cell is highly recommended because it’s safer than the unprotected battery. An average 18650 cell consumes about 4 hours of charge time. However, its charge time can be affected by various factors such as the voltage and amperage of the charger.


The recharge cycles for this cell are limited, and they vary depending on various factors. For instance, conditions such as temperature may have a considerable impact. It degrades each time when it’s recharged due to electrochemical degradation and oxidation. Degradation happens to all rechargeable batteries such as AA, AAA, 14500, 21700, and 26650.

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Can you charge 18650 battery with an AA charger?

No, you cannot charge an 18650 battery using an AA charger. An AA battery has a voltage of about 1.5V, and it has a 2V cutoff voltage.  This charger will not work if it reads anything more than 2V. An 18650 battery usually has a range of 3V dead cells.

When you connect an AA charger, the power will cut off instantly. Using an AA charger is very dangerous because it can cause an explosion or the battery can catch fire. You need a safe way to charge an 18650 battery because they are very dangerous.

Other dangers associated with charging this type of cell with the wrong charger include.

●The battery will suffer capacity reducing damage

●It can experience a thermal runaway

●Catching fire


●It can release toxic gases

All these issues can be caused by using a charger that has a high voltage above 4.2V or 4.3.V.

Any standard type can withstand a maximum of 4.35V. This is mostly found in some high capacity models. An AA charger is designed to release a maximum of 2V. If you want to use this type of charger, then you have to modify it first.

Take it to a professional if you don’t have the experience so that you can reduce the dangers associated with the wrong configuration. A small mistake while doing the modification can cause the cells to explode or catch fire.

So you can use an AA charger, but it has to be modified to increase the voltage. Using an AA charger without any modification will not work because lithium batteries average a voltage of 3.7 V.

What is the best charger for 18650 batteries?

The 18650 battery has many applications. This is the main reason why you need an excellent charger. Furthermore, there are many products that rely on an 18650 cell, such as flashlights and vapes.

The following are some of the best 18650 battery chargers

1.Xtar DRAGON VP4 Plus

If you are looking for the best charger on the market right now, then you should try the Xtar DRAGON VP4 Plus. This charger is more extensive than most four-bay chargers and it’s made from a heat resistant plastic.

It features a USB connection, 3A/12V power supply, a USB output and a battery pack for 11.1V/3s. It has a straightforward user interface made of only three buttons. A display, record/test, and current/refresh.  The screen shows the battery type, charge current, displayed slot and mode. Furthermore, it has a lively bar showing the charging rate.

2.Smart universal battery charger MiBOXER

This charger is the best for the people searching for a charger with a large digital display. It can show charging time, battery type, current, battery capacity data, voltage, and internal resistance.

It has eight battery charging bays. The settings are very easy and can be done with just one click. Furthermore, you can set the batteries to charge any rate you want. This battery charger is automatic so you can just insert your cells and it will charge them at a favorable rate.


How to choose the best 18650 cell charger

Chargers are not created equally. This means that some work better than others. Other are very long-lasting while others are of low quality. However, if you want to choose the best charger, then you should put the following factors into consideration.

●Overcharging protection

●Charging indicators

●Independent charging bays

●Safety features

●Number of ports

●Quick charging technology

How do you make an 18650 battery charger?

Making an 18650 battery charger is very easy with the following steps.  The materials are also easy to find.


●18650 battery

●A paper clip

●5V power source


●Thin steel wire

●Tp4056 module

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After collecting all the required items, you need to follow the following procedure.

Step 1: Take a paper clip and bend it, forming triangular shapes.

Step 2: Use an 18650 cell to mark a PCB and then solder the clip firmly onto it

Step 3: Place a thin steel wire on the sides of the 18650 cell. Place another steel wire on the other side.

Step 4: Mark, your positive and negatives.

Step 5:  Your charger is ready. Simply place your batteries between the paperclips. Now connect the 5 V power source. Viola! Your cells are now charging.

The above charger that we have constructed will you an approximate of 4 hours to charge your 18650 battery. But a micro USB charger only takes 3 hours. Note that the charging times may sometimes vary even if you are using new cells.

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