7.4V Lithium ion Battery Pack Manufacturer

  • Manufacture 7.4V 2 series lithium battery pack since 2010.
  • PCM (protection board) customized available. 
  • It can be a series combination of lipo batteries and 18650 batteries.
  • PVC wrap, ABS, Metal housing can be chosen.
  • Short-circuit, over-current, over-voltage protection.

What is the 7.4V lithium-ion battery pack?

18650 2S1P 7.4V 4400mAh

Below is a simple explanation of each parameter:

  1. 4.4Ah capacity, when the lithium battery is fully charged, the voltage is up to 8.4V. It can last 1-hour running time when the discharge current is at 4.4Ah.
  2. 1C rate, usually max pulse discharge rate 2C. As we all know, the discharge current will be changed with the load. It can support 1C 4400mA current to discharge.
  3. 2S1P means that the battery is composed of two 3.7V series connected in series, one parallel connected, and the total voltage is 7.4V. By connecting batteries in parallel, the voltage can be kept constant and the discharge current can be increased, but the battery life will not be prolonged.

What are application of 7.4V lithium-ion battery pack?

The important characteristics of the 7.4V lithium-ion battery pack are: high energy, high density, high voltage, no pollution, no metal lithium, high cycle life, no memory effect, and fast charging. So it has received the attention of many industries.

Because of its attention, it has a wide range of applications. Let’s take a look at it in general.

  • Laser measuring instrument, laser distance meter, laser langefinder, digital laser.
  • CCTV camera, video camera, digital camera, network camera, Analog Camera.
  • Neck massage, shoulder massage, cordless massage, back massage.
  • Portable printer, thermal printer, hand held printer, coding printer, label barcode printing.
  • LED torch, flashlight, camping light, outdoor light, outdoor camp.
  • Medical device with battery, blood pressure monitor, glucose meter, physical therapy equipment.

Detailed explane of 7.4V lithium battery charging circuit diagram

  • circuit design image as the right.
  • This part of the circuit is to output 8.4V to charge the lithium battery.

    TP5100 is a switching step-down dual-cell 8.4V/single-cell 4.2V lithium battery charge management chip.

    TP5100 has a wide input voltage of 5V-18V. The battery charging is divided into three stages: trickle precharge, constant current, and constant voltage. The trickle precharge current and constant current charging current are adjusted by external resistors, and the maximum charging current is up to 2A.

circuit design
  • A typical constant current circuit is composed of LM317 and R1, R2, and R3 (431 temporarily considers that disconnecting R4 is relatively large, so you can ignore it first). Maintain a constant charging current when the voltage is not too high. Take the charging of two batteries as an example. Under ideal conditions, the charging current should be constant until the voltage reaches 8.3V. When the voltage at point A reaches the inflection point value of 8.3V, after the partial pressure of R4 and R5, TL431 starts to turn on, and gradually pulls the reference point voltage of LM317 from 8.3V down. The so-called inflection point is the point where the current begins to drop. Until the voltage reaches the 0 current point of 8.4V, point A still maintains this 8.3V voltage, the output Vout of LM317 drops to 8.4V, and its adjustment end drops to 7.17V.
circuit diagram

How do you charge a 7.4V lithium-ion battery?

  • The 7.4V lithium-ion battery charging limit voltage is 8.4V. If charging behavior occurs, the load is well calculated.
  • It depends on the voltage at both ends of the battery. The current multiplied by 2A is its load power.
  • The voltage of the battery will rise from the initial 7.2V to 8.4V. If it is not cut off at this time, the battery voltage will continue to rise to about 8.60V.
  • If there is no protection of the protection line at this time, the voltage will continue to rise until 12V (of course, it may be overcharged or even exploded in the middle).
  • It can be charged with two 4.8V chargers, but a voltage detection must be installed. After the battery voltage rises to 4.2V, the charger must be disconnected.
  • The safest charging is of course to install a 7.4V protection circuit, so that there will be no battery failure due to excessive voltage.
  • And you don’t have to worry about the battery being discharged below 2.5V when you use it. At the same time, it also has the function of overcurrent protection and short circuit protection.

Lithium Battery Process Work Flow

We are a professional lithium battery factory in China. Now we briefly introduce how to produce lithium batteries. It starts from cathode & anode mixing, coating, baking, calendering, automatic slitting & cutting, winding, top & side sealing, electrolyte injection, pressing formation, forming, capacity grading, OCV1 & OVC2, cell to PCB, insulation and shipping. Welcome to contact and ask for the workflow table list.

Need Any Customized 7.4V Lithium-ion Battery Pack?

How many mAh is a 7.4V battery?

When we talk about 7.4V battery, it generally refers to 18650 battery. We mostly use 18650 cell at 1800mAh, 2000mAh, 2200mAh, 2500mAh, 2600mAh, 2900mAh and 3300mAh. We can choose their capacity based on customer discharge demands.

Except for 18650 2S1P battery pack, we can parallel some 18650 cells. They can be 2P batteries, 3P batteries, and even more. It can support longer running time. The total 18650 cell amounts will be larger. 

How I charge 7.4V battery with 5V?

5V input to charge the 7.4v battery, it is necessary to use boost charging technology. For example, using 5V2A input, to the battery terminal, according to the battery voltage of 8V, the actual input to the battery current algorithm is 5V*2A=10w, then the efficiency of 0.85 is 8.5w, and the actual charging current is about 1A according to the battery voltage of 8V. If you press your battery capacity of 2100mAh for about 2.5 to 3 hours, I know that an FLD5301 is a very simple SOP8 package or a dual-light indicator. Adaptive input.

What is the highest voltage lithium battery?

It depends on the lithium-ion battery material chemistry system. 

Ref 18650 battery and polymer battery, the rated voltage 3.7V, and charge cut-off voltage 4.2V.

Ref LiFePo4 battery, the rated voltage 3.2V, and charge cut-off voltage 3.65V.

Contact us for 7.4V lithium battery solution

Why choose us, HlcBattery?

  • Safety & Reliability
    All Battery cells will pass rigorous testing. All Battery Packs are Certified and are compliant with regulatory and safety requirements. 
  • Certifications
    CE, ROHS, FCC certification and high reliability. MSDS, UN 38.3, IEC 62133, KC, PSE, BIS certifications and more available.
  • Customer support
    Quick turn-around on battery assemblies(10-20 Days). 24*7 services are available.

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