Custom 7.4V Li ion Battery Manufacturer in China
VTCBATT is a trusted OEM supplier of 7.4V Li ion batteries, delivering thin, lightweight, and powerful energy solutions for RC hobbies, drones, and portable electronics. Our 7.4V 2S Li ion battery is composed of two cells in series, offering a nominal voltage of 7.4V with an output range from 8.4V (fully charged) to 6.0V (discharged).
We offer capacity options from 300mAh to 28Ah, along with built-in protection circuits, optional NTC sensors, and balancing cables to ensure safety and stability. Each pack supports custom wire gauge and connector types, including JST, Molex, and Hirose, to fit your specific application.
7.4V Li ion Battery Model
Advantages of VTCBATT 7.4V li ion batteries
7.4V is the voltage of two standard 3.7V lithium batteries connected in series, making it suitable for direct use in many electronic devices without the need for complex step-up or step-down processing.
The voltage changes smoothly throughout the discharge process, allowing devices to maintain optimal performance.
Compared to nickel-metal hydride (NiMH) or lead-acid batteries, lithium batteries have higher energy density, are smaller and lighter, and offer longer battery life.
The typical cycle life of a lithium battery is between 300 and 1000 cycles (depending on quality and usage environment), which is unmatched by many disposable batteries.
Supporting high current discharge, it is suitable for power devices such as remote-controlled models, drones, and power tools.
Energy loss is minimal when the device is idle, and the charge level does not decrease rapidly, even after prolonged storage (approximately 1-2% per month).
Compared to nickel-cadmium batteries, lithium batteries do not experience the “memory effect,” allowing them to be charged and used at any time without affecting their capacity.
It can be designed into various shapes, including cylindrical, square, and soft-pack, to accommodate the space requirements of different devices.
How Automation Assures Quality Consistency in Battery Manufacturing?
Battery quality consistency is demonstrated in battery voltage, capacity, internal resistance and self-discharge.The high-automation process not only enssures quality consistency,but also improves production efficiency, reduces labor costs and enhances battery safety. During each manufacturing process,quality consistency data is automatically recorded by machines and uploaded to the MERS system automatically, enabling tracebility of each lot. Thus, quality consistency can be clearly observed in every process of VTCBATT’s modern facility.
Applications of VTCBATT 7.4V Li ion Batteries
Consumer ElectronicsPortable audio and video equipment; portable DVD players, external power supplies for digital cameras; game controllers (such as the Switch); smart hardware; Bluetooth speakers, e-book readers; remote controls for model aircraft.
Industrial and Commercial EquipmentAutomation equipment: POS terminals and barcode scanners (accounting for over 60% of the commercial payment terminal power supply market); industrial robot joint drive power supplies; remote-controlled vehicles; drone power systems (with a battery life of up to 20-30 minutes); RC racing cars/model boats (supporting 2C continuous discharge).
Specialty EquipmentMedical equipment includes backup power supplies for portable ventilators and infusion pumps, handheld ultrasound diagnostic equipment, security systems, wireless surveillance cameras (supporting -20°C operation), and GPS trackers (for vehicle/asset location).
Emergency and Lighting EquipmentEmergency power supplies, emergency lighting systems (with a battery life of 8-12 hours), small UPS uninterruptible power supplies, outdoor lighting, headlamps and camping lanterns (with brightness up to 1000 lumens), and solar street light energy storage units.
Other Innovative ApplicationsEducational robotics teaching aids, auxiliary power for electric scooters, and power supply for IoT sensor nodes.
It depends on which is best suited for your device. 7.4V batteries are pre-assembled by the manufacturer in parallel and include protection circuitry, making them safer. Two 3.7V batteries offer greater flexibility and can be used by the customer, but they aren’t as safe. Here are the detailed differences between the two:
The 7.4V battery has more convenient packaging, comes with a built-in protection board and charging port, making it easier to use than two 3.7V batteries. Furthermore, the 7.4V battery has a built-in protection board, while assembling two 3.7V lithium-ion batteries yourself carries a higher risk.
However, the 7.4V battery has a fixed form factor. While space-efficient, it can only be used with compatible devices. The two 3.7V batteries can be used in any device designed to use two 18650/21700 cells.
The cost of the two batteries is also different. The cost 7.4V battery is often higher than the two 3.7V batteries, and maintenance costs are higher, too.
7.4V lithium-ion batteries support high-rate discharge, with instantaneous currents reaching tens of amperes, making them suitable for high-power devices. Their energy density is also higher than other batteries, allowing for longer battery life within a given volume. For example, A nickel-metal hydride battery of the same capacity is twice the volume of a lithium battery. The monthly self-discharge rates of less than 5% make them good performance too.
However, 7.4V lithium-ion batteries also have limitations, large voltage fluctuations, and the need for strict cell matching when connected in series. They also have a higher risk of thermal runaway than other battery materials, necessitating built-in short-circuit and temperature protection.
Overall, at the same voltage, 7.4V lithium-ion batteries are more suitable for high-power, compact devices, and safety-sensitive applications (LifePO4 is an option). The balance charger and protection board are a must, and the cells should be inspected regularly.
Firstly, the principles are different: Lithium battery is a non-rechargeable battery and the operating materials should be metallic lithium (Li/MnO2 or LiSOCl2), and its reaction cannot be reversible after discharging. Lithium-ion batteries are secondary batteries that are capable of operation on a charge/discharge cycle by moving lithium ions in and out between a positive electrode and a negative electrode.
They are also different in performance: the lithium-ion batteries have a higher energy density (150-250 Wh/kg) and are used in high-energy devices. They also have a higher initial voltage (3V onwards), low-temperature efficacy than some other choices. Lithium-ion batteries can tolerate 500-1000 cycles, whereas lithium-ion batteries are disposable. Their self-discharging rate is only a bit less than 1.5% monthly, vs. much higher rates of around 5% in lithium-ion batteries.
They also differ in the security aspect: Lithium-ion batteries bring metallic lithium dendrite growth risk, charging can be a short-circuit (charging is generally not allowed at), while the other is free. Lithium-ion batteries require protection circuits for overcharge/overdischarge, but further structural optimization for safety is also possible.
In addition, the cost of a single lithium battery is about 30% lower, and the cost of use is also lower.
In general, lithium-ion batteries are best for applications needing a long life and high-level maintenance-free devices, whereas lithium polymer batteries are better for those devices that are frequently charged and discharged, such as for mobile phones or energy storage systems.
This depends primarily on capacity and usage conditions.
High-power devices (such as drones and power tools) will significantly shorten use time, while low-power devices (such as remote controls) can extend use time. Under normal use, the battery can last up to 300-500 full charge-discharge cycles (capacity decay to 80%). If only 50% of the battery is used before recharging, the cycle count can be increased to approximately 800. Using a dedicated balance charger can extend the battery life by 20%-30%.
Improper use can shorten its lifespan: Low temperatures of -20°C can cause a capacity drop of approximately 30%2, and prolonged high temperatures (>45°C) can accelerate aging. Deep discharge (e.g., using 3V/cell) can shorten its lifespan.
Therefore, it is recommended that you maintain a battery charge between 20% and 80% during daily use and maintain a charge of 50% (approximately 3.8V/cell) for long-term storage. Avoid charging or discharging at rates exceeding 1C (e.g., a 6000mAh battery should have a maximum charge and discharge current of ≤6A). Based on an average of once a day usage, the capacity will drop significantly after about 1-1.5 years of normal use, and replacement will be necessary.
Appearance Inspection
Check the battery for bulging, cracks in the casing, or leaking liquid. These are direct signs of electrolyte leakage or internal short circuits. If the battery surface shows signs of scorching or oxide seeping from screw connections, it indicates damage. If a sweet or pungent odor is emitted during charging or use (electrolyte leakage), or if the temperature rises abnormally locally (internal short circuit), discontinue use immediately.
Voltage and Capacity Test
No-Load Voltage Test
Use a multimeter to measure the battery voltage. A fully charged state should normally be 8.4V (7.4V x 2 cells in series). If it is below 8.0V, it may be aged. The lower discharge limit should not be below 6.0V (3.0V per cell). If the voltage drops below this value, it may be permanently damaged. A voltage drop of more than 20% when connected to a load, or a significant reduction in battery life, indicates severe capacity degradation.
Charging Status Assessment
Unable to charge to 8.4V, or excessive heating during charging (normally should be slightly warm). The charger displays a “Fault” message (e.g., if the BMS protection function is triggered). If you encounter the above situation, please stop using it immediately and recycle it according to local regulations.
