3.7 V Li Ion Battery Charger - Introduction and Charger Types

Dec 06, 2021   Pageview:172

The 3.7v lithium battery is a type of lithium battery that has a nominal 3.7v voltage and 4.2v. 3.7 Volt lithium-ion rechargeable battery voltage at full charge. These types of cylindrical batteries are mainly used in cordless Power Tools, flashlights, electronic cigarettes, phones and laptop battery packs.

24V Emergency Starting Power Supply,Low Temperature Large Current
Low Temperature Large Current 24V Emergency Starting Power Supply Battery specification: 25.2V28Ah (lithium battery) , 27V300F (supercapacitor pack) Charging temperature:-40℃~+50℃ Discharging temperature: -40℃~+50℃ Starting current: 3000A

Types of 3.7 V Li Ion Battery Chargers

The market has battery charges of two different types. These are Smart Chargers, also referred to as Intelligent Chargers, and Timer Control Charges - each of which comes at a different cost. The cost of Timer Controlled Chargers is relatively less.

Two different types of technologies are used by these chargers. It is essential to understand the difference between the two types of technologies before you purchase a charger, so as to be able to make the most suitable choice for your purpose.

Timer Controlled Battery Chargers

These chargers are pre-set at the factory level and have an integrated shut-off automatic timer. To put it simply, all the batteries within this type of charger charge for the same amount of time. When there is a lapse of the pre-set time, the unit gets shut off automatically and there is no more delivery of any charge.

This is a simple device which cannot gauge how much charge is left in each specific battery. Naturally, all are charged for the same amount of time - irrespective of how much of “topping off” is required by each one. This is a low-cost way of battery charging, although it tends to undercharge and overcharge some batteries, as it cannot detect how much charge is needed by each one. The overcharged batteries get damaged. Naturally, before buying a timer control charger, you have to weigh the pros and cons of going for a cheap charger VS wasting money on damage batteries.

Smart/ Intelligent chargers

These can detect missing voltage through the assessment of the peak voltage remaining in every battery that is connected to them. Naturally, these are able to custom-charge every battery as needed. Although this is an expensive technology, there are major benefits. Batteries are not damaged, because this type of charger cannot overcharge or under-charge batteries. Naturally, it lets users rest assured that they will not have to check the status of charge of any of their batteries that they are trying to recharge.

Chargers of both types are available for 9 V, Sub D, Sub C, C, AAA and AA sizes and in the chemistries NiMh and NiCd. Multiple chemistries and / or multiple sizes can be accommodated by universal chargers simultaneously. 

Low Temperature High Energy Density Rugged Laptop Polymer Battery 11.1V 7800mAh
Low Temperature High Energy Density Rugged Laptop Polymer Battery Battery specification: 11.1V 7800mAh -40℃ 0.2C discharge capacity ≥80% Dustproof, resistance to dropping, anti - corrosion, anti - electromagnetic interference

3.7 V Li Ion Battery Charger Circuit

There is one microchip MCP73831 at the heart of the 3.7 V Li Ion battery charger circuit. It is available in the package SOT-23-5.

This microscope is a very advanced linear charge management controller that is designed to be used in applications that are cost sensitive and limited in terms of space. Constant Voltage charge algorithm / Constant Current algorithm is used by this IC, with selectable charged termination and selectable preconditioning.

How Do You Charge a 3.7V Li Ion Battery Without a Charger?

When you wish to charge a 3.7 Volt lithium ion battery, using a proper charger is the most effective as well as the safest way to go about. Chargers are designed specifically for these types of batteries, with proper amount of voltage and current, to avoid battery overheating problems. Due to this reason, it is always recommended to use a charger and carry it wherever you go. But if you forgot your charger or misplaced it, here is how you can charge your 3.7V Li ion battery even in the absence of a charger.

Method 1: Use a USB Port

The quickest way to get your battery charged, even in the absence of a charger, is the use of Universal Serial Bus (USB). It is as safe and effective as a normal charger; you only need a host device and a USB cable.

In this case, the host device is the power source. Frequently, these types of devices are Power banks, cameras, car radios, printers and PCs, among others.

For battery charging, you have to connect the cable’s larger end to the host's port and the smaller end to the specific device that you want to get charged. Keep in mind that at a time, regular USB cables are able to charge just one small-sized, single-cell lithium ion battery. This is due to the fact that only up to 500Ma current is released by USB port.

Safety Warnings: Keep in mind that you should not charge any device which consumes higher than 500mA current. If you do this, it will surpass the current limit of the port and drop the voltage of your host device. It might result in the failure of system.

You should also remember not to charge multiple batteries simultaneously. A USB hub is able to charge only one single-cell lithium ion battery at one time. Trying to charge multiple batteries will cause overloading and put the battery at risk.


Make use of an Alternative Source of Energy

It is another effective method of charging a 3.7 v lithium ion battery in the absence of a charger. Which type of alternative source of energy can you use? A solar-enabled charger can be a good option. It can cost just 15 dollars to you. However, such kinds of chargers are heavy in size and carrying these about is not a practical solution.

A hand crank charger is another source of alternative energy. Such kinds of chargers are used more frequently as an alternative power source during cases of power outage. These are heavier in size as compared to solar chargers.

Can You Use A Regular Battery Charger On A Lithium Ion Battery?

That is possible so long as you are able to set the charger's maximum voltage and as long as automatic equalization mode is not enabled in the charger.

Most of the modern chargers allow you to deactivate that feature and the charger should safely be used if it can be turned off.

In case you choose to use a lead acid charger with disabled equalization mode for charging 3.7 V lithium-ion battery, you need to have the battery disconnected as soon as it gets charged fully; so as to avoid battery damage.


Leave a message

Contact Us
Your name(optional)

* Please enter your name
* Email address

Email is required. This email is not valid
* How can we help you?

Massage is required.
Contact Us

We’ll get back to you soon