How To Charge A 18650 Battery

A 18650 battery is a rechargeable lithium-ion battery. The battery is also referred by the name “18650” cell. It has up to 3.7 volts and 1800mAh to 3500mAh.

How can I charge my 18,650 battery? You need a charger designed for nickel batteries to charge the 18650 battery. The charger must have indicator lights that have a specific light that indicates a full charge. You will need the following to charge your 18,650 battery:

● Standard charger
● Source of electric current
● Cables for wireless charging

18650 batteries are known to have a huge storage capacity, high voltage, and excellent temperature performance. This calls for a charger that meets the demands that come with the battery.

A good charger should have a green color to indicate that the battery is fully charged and no light when disconnected. It will take a maximum of 5 hours for the battery to be fully charged.

Which Tools Do You Need to Charge a 18650 Battery?

The 18,650 battery is a rechargeable battery. They are common in many devices such as flashlights, baby monitors, smartphones, fitness gadgets, and cameras. For you to charge the battery, you need a charger that is compatible with your battery.

When fully charged, the battery can last between 300 to 500 charge cycles. The type of charger you will use on your battery will affect the length of time your battery will last. Generally, all rechargeable batteries degrade over time.

4 Ways to Charge an 18,650 Battery

You can charge your 18650 battery in four main ways:

1. Use of a standard charger
2. Wireless chargers
3. Use of USB
4. With solar panel

1. Use of Standard Chargers

Wired charging will allow you to use a charger with a cable. These chargers have indicators that will let you know when the battery is fully charged. The chargers vary depending on the output of the current they produce.

The use of a compatible charger can charge all 18650 batteries. These chargers come in different sizes and capacities. To be sure of the charger you use, check the input requirements to choose the most compatible charger. The best 18650 chargers come with indicators installed inside.

Here is the great YouTube video I found for you below:

2. Use of Wireless Chargers

Wireless charging is where you do not require any cable to charge your 18650 battery. One of the wireless methods of charging your phone is by using trickle charging.
Trickle charging is used to charge a majority of rechargeable batteries. By applying trickle charging, you will be providing a low amount of current for the battery to absorb.

If you intend to charge a depleted battery, you should be ready to wait for a longer time for the battery to be fully charged than other modes of charging. Trickle charging involves connecting a wire to the bulb being used and connecting the other end of the cable to a battery terminal. Power will be sent from the car battery to the bulb, and the bulb will light up.

Another wireless mode of charging the 18650 battery is by use of alligator clamps. This is achieved by using small alligator clamps at the end of the cables and connecting the positive side to the negative terminal of the battery you are charging. This should be done with care to avoid reversing the polarity of your battery.

Here is the great YouTube video I found for you below:

3. USB port Charging

The USB charging is ideal for use in car charging systems, car charging, laptops, and other devices with a standard USB Port. Some USB chargers are customized with multiple inputs that will charge many types of batteries.

Here is the great YouTube video I found for you below:

4. Use of a Solar Panel

There are several options available on the table when it comes to charging your battery. If you are out for camping or relaxing at your home compound, you can get a portable charger that will charge your battery.

Those who prefer using solar panels for their electricity needs can install a home solar panel and use it to charge the battery. The output of the charger must be according to the requirements of the battery.

Here is the great YouTube video I found for you below:

How Long Do 18650 Batteries Take to Charge?

Before talking about the length of time taken to charge a 18650 battery, let us first discuss the factors that may affect the time taken to charge the battery:

• Type of charger used
• Battery life and condition

The amount of time your 18650 battery will take to charge depends on the type of charger you decide to use on your battery. Wireless charging will take a longer time for the battery to be fully charging.

On the other hand, charging via a compatible charger will take a shorter time. The condition of the battery will also affect the length of time taken to charge the battery.

A battery cycle is the amount of time taken to charge and discharge a battery. A 18650 battery can be charged up to 4.2 volts. The battery will discharge by up to 2 volts. Always ensure your battery is not discharged to zero volts. This will decrease the battery life at a faster rate than average.

The life cycle of a 18650 battery is 300 to 500 cycles. With time, as the battery is used, the cycle will reduce by up to 200. Eventually, the circles will decrease to 50 as the battery degrades with time. The average charging time for a 18650 battery is 4 hours. This applies to new batteries. Degraded batteries will take up to seven hours to be fully charged.

The amperage and voltage of the charger affect the length of time taken to charge the battery. When the battery is new, it is delivered with half charge. This is done intentionally for the battery to remain healthy. Charging a half-full battery takes only 2 hours.

Your battery should indicate the amounts of charge in it through the device it is installed or through lights that are located on the charger. The bigger the battery capacity, the longer it takes to charge. Always opt for a charging method that works with your device.

What Current Should You Charge Your 18650?

Your 18650 battery will last longer if it is charged with a steady current of 0.5 amps. Always keep your battery on charge for 4 to 5 hours daily. You can opt to charge with amperage of 0.25, but it will take a longer time than that of 0.5 amps. Charging your 18650 with currents above 18650 will lead to shorter battery life.

If the battery discharges by up to 100 percent, it means that the battery is fully damaged and cannot function well. Always remember that the higher the rate of charging the battery, the more the battery life is shortened.

Which Charger Will Work Best With My 18650 Battery?

As discussed above, there are several options for charging your 18650. Before choosing a charger for your battery, you should evaluate the type of battery you intend to charge. There are two types of 18650 batteries.

• Protected batteries
• Unprotected batteries

Protected batteries have an electronic circuit that is located on the cell packaging. They are cheaper than their counterparts but are widely regarded as unsafe by many users. The do not poses an electric circuit in the battery cells.

Protected batteries are considered safer than unprotected batteries. Whenever you intend to dispose of an unprotected battery, always follow safety precautions to avoid any accident.

You will need a good charger for you to keep your 18650 healthy and in shape. The best types of charger to use are standard chargers. These are chargers that have a cable that can be connected to the device holding your battery.

1. Most normal chargers used to charge a 18650 battery have light indicators. The indicator will glow with a green light when the battery attains full charge. A standard charger should take at least 4 hours to charge the 18650 battery fully.

2. Wireless chargers are known to be slow chargers due to the low current they supply to the battery while charging. The output of wireless chargers ranges between 0.25 amps to 0.3 amps. This will translate to a longer charging time will may last up to 7 hours.

3. USB and solar panel chargers will charge your battery with amperage of 0.3 amps to 0.4 amps. This is relatively lower than the amperage produced by standard chargers. This makes regular chargers the best types of chargers for charging your 18650.


18,650 batteries are commonly used in devices such as laptops, mobile phones, electric vehicles, and flashlights. The devices require regular charging for them to be functional.

The source of your current will affect the charging time and the overall battery life. Note that there is internal resistance in all lithium batteries, which will prolong the charging time. You should avoid leaving your 18650 battery until it gets fully discharged.

1. 18650 Cell charge times? – Singletrack Magazine