18650 Lithium-ion Battery Pack

  • 18650 lithium-ion battery packs since 2010.
  • Custom PCM/BMS for different devices.
  • Provide standard RS485, RS232, CAN BMS Protocols.
  • Capacity, Size/dimension can be customized.
  • PVC wrap, ABS, Metal housing can be chosen.
  • Short-circuit, over-current, over-voltage protection.
18650 lithium-ion battery pack

Why choose 18650 lithium-ion battery packs?

  1. Big capacity. The capacity of 18650 lithium-ion battery is generally between 1200mah and 3500mah.
  2. Long lifespan. The cycle life of normal use can reach more than 500 times.
  3. High safety performance. Non-explosive, non-flammable; non-toxic, non-polluting.
  4. Can be combined in series or parallel to form 18650 lithium-ion battery packs.
  5. Wide range of use. Suitable for energy storage power supply, power battery and consumer electronics.

How to charge 18650 lithium ion battery pack?

In addition to high voltage charging, constant voltage charging, constant current charging. Intelligent charging: This is the ideal charging management method. It follows the charging algorithm mentioned at the beginning of this section and is integrated in a small SMD IC. The peripheral circuit is simple, stable and reliable, such as TP4054/4055/4056/4057 , TP4002/5000, MAX1879, etc.

The main feature of this chip is that it will monitor the voltage and current at the same time when judging whether it is full, stop charging at 4.2V, or stop charging when the charging current is less than 0.01C (usually about 50mA); completely cut off after full, no trickle floating charge , but monitor the voltage at any time, if the 18650 lithium battery voltage drops to a certain value and then start charging.

18650 battery applicant

18650 lithium-ion battery packs are commonly used in a broad spectrum of applications, including:

  • Energy storage. Mainly used in base station power supply, clean energy storage, grid power storage, home solar storage system, etc.

  • Power class. Mainly refers to electric vehicles, electric bicycles, new energy vehicles, etc.

  • Digital consumer electronics. Mobile phones, tablets, laptops, electric toys, MP3/MP4, earphones, power banks, model airplanes, power banks, etc.

How to tell if 18650 is bad?

  • The fastest inspection method is to test the internal resistance and the maximum discharge current. A good quality lithium battery pack has a very small internal resistance and a large maximum discharge current. Using a multimeter with a range of 20A, directly short-circuit the two electrodes of the lithium battery, the current should generally be around 10A, or even higher, and it can be maintained for a period of time. A relatively stable battery is a good battery.
  • Look at the appearance. The fullness of the appearance, such as the general lithium battery of about 2000mAh, is relatively large. The workmanship is more delicate or the packaging is plumper.
  • Check the hardness. The middle part of the lithium battery can be squeezed lightly or moderately by hand. The hardness is moderate, and there is no soft squeezing feeling, which proves that the lithium battery is a relatively high-quality battery.
  • Look at the weight. Remove the outer packaging to see if the weight of the battery is relatively heavy. If it is heavy, it is a high-quality battery.
  • During the charging process of the 18650 lithium battery pack, if the two poles of the battery do not become hot after continuous discharge for about 10 minutes, it proves that the battery protection board system is perfect. Generally, the quality of lithium batteries with high-quality protection boards is better than that of ordinary lithium batteries.
lithium battery charging

Why do 18650 batteries explode?

  • Internal short circuit: Structural or workmanship defects lead to tab insertion, too little diaphragm wrapping, burrs, diaphragm discount, etc.
  • External short circuit: The explosion after combustion caused by the external short circuit of the lithium battery below 1AH is rare. Usually, it is bulging or the tab is simply blown. The personal analysis is the combustion caused by the external short circuit of the power battery or the large-capacity mobile phone battery.
  • Overcharge explosion: This is the most dangerous and most feared by enterprises, but it still occurs occasionally. From what I know, there are two points: the user does not use the matching charger as required, thereby destroying the protection circuit, and the user often charges for an unlimited time, which is difficult without frying; the 18650 lithium battery is unreasonable. And the protective plate fails, and in this case, it will also explode in a mess. Same goes for a single battery.
battery expansion

How to make a lithium ion battery pack?


To understand the real demands of the lithium-ion battery pack design, you need to provide the lithium battery size, electrical performance requirements, output requirements, and functional information.

Quick Response

Evaluate a solution and quote the known parameters provided by the customer, also provide full datasheet for reference. We will consider the cell selection, circuit and structure design to final assembly.


After the customer’s approval, we will start to make samples for the lithium-ion battery pack, and provide charging and discharging cycle curve and data.

Sample Test

Before delivering out, we definitely do battery pack aging test. Assist and track customer test results, as well as customer’s overall equipment operation effect.

Certificate Proceed

We will discuss with customer certificate works based on the final country and applicate requests. It may be MSDS, UN38.3, IEC62133, KC, PSE, etc.

Mass Production

Develop process documents and BOM sheet, purchase materials, arrange staff production, quality personnel monitoring, and random inspection, and package and shipment.

18650 lithium-ion battery pack procedure as right flow chart

It includes the whole 14 steps to whole lithium battery packs. It includes cell inspection & test, solder PCB/nickel strip/cell, highland barley paper insulation, aging test, packing and delivery.

18650 lithium battery pack procedure

Manufactured to National Standard GB/T18287-2020

  • All are producing at 5S & dust free plant. Our daily production is up to 10K pieces.
automatic sorting machines
18650 battery sorting
our workers

Chemical Test

Automatic Welding

Final Testing

  • Cell Formation & Grading
  • Temp & Hum Controller
  • Short-circuit Test
  • Salt Spray Test
  • Molding System
  • Automatic Welding
  • Automatic Welding
  • Final Test
  • Packing

Need Any Custom 18650 Lithium-ion Battery Pack?

You will receive the charge & discharge curve

  • 12S2P Battery Pack, It is a 5A charge & 10A discharge curve test as a sample for your review.

Time - voltage & current

Capacity - voltage

Time - capacity & specific capacity

Cycle number-charge capacity & discharge capacity & charge specific capacity & discharge specific capacity

Product & Factory Certificates

  • All batteries are require related certification apart from lab testing, such as voltage, current measure, and each countries have different certificate demand.
  • Clients are welcome to have any 3rd party certification company verify our batteries or the factory documents.
  • We have been working with UL, TUV, SGS certication lab. All batteries approved by UL1642, UN38.3, IEC62133, PSE, KC, CB, MSDS certificate or report.
battery certificate

Write To Us

FAQ of 18650 battery pack

  • Lithium-ion battery storage temperature

    The battery should be stored at room temperature, and charged to 40%~60% electric quantity.

  • How long does a 2.5Ah battery last?
    It can last 5~6 hours based on a 0.2C discharge rate. It can last 1~2 hours based on the 1C discharge rate.
  • How long to get samples?
    Generally, 7 days lead time for small quantity samples.

Ask For A Quick Quote

We will contact you within 1 working day, please pay attention to the email with the suffix “@hlcbattery.com”