Portable Bluetooth player 18650 lithium battery.
With the development of modern society, entertainment methods have begun to shift towards outdoor activities, and many entertainment facilities are also tending towards outdoor types. Portable Bluetooth player is one of the equipment products generated by outdoor entertainment. Due to its compact and portable design, high-quality speaker effects, and special features such as integrated home power players and Bluetooth transmission, it has become the preferred outdoor entertainment device in modern society. Due to the requirement for portability, providing a safe, efficient, stable, lightweight, and sufficient backup power solution for portable Bluetooth players has become an important guarantee for people to engage in long-term outdoor entertainment. The backup battery for portable Bluetooth players has become the preferred power solution for outdoor entertainment devices due to its unique advantages.
1、 Design requirements for backup lithium batteries for portable Bluetooth players:
The working current of the player is relatively small, but the battery is required to have a continuous working time of at least 8 hours to meet the equipment's continuous working time. The battery should have over temperature protection function, and the finished battery should pass UL2054 certification requirements. The weight of the battery should be controlled within 200g. For this purpose, our company adopts imported Samsung battery cells, which have the advantages of high energy ratio, light weight, small size, high cycle life, high safety, high voltage, and good consistency. The lithium battery pack is designed to output an overcurrent protection value of 15A, a maximum continuous operating current of 2.2A, and a charge capacity of 2.2Ah, fully meeting the power consumption time requirements of the player. The specific design requirements and parameters are as follows:
1) Design requirements for lithium battery pack model: 18650-3S1P/2.2Ah/11.1V.
2) Circuit design requirements:
1. Single section overcharge protection voltage: 4.35 ± 0.25V
2. Single section overcharge recovery voltage: 4.15 ± 0.50V
3. Single section over discharge protection voltage: 2.40 ± 0.08V
4. Single section over discharge recovery voltage: 3.00 ± 0.10V
5. Combination battery overcurrent protection value (10ms): 10~17A
6. Combination battery over temperature protection value (recoverable): 70 ± 5 ℃
7. Finished batteries have short-circuit and reverse charge protection.
3) Design requirements for battery cycle life: 300-500 times (according to national charging and discharging standards)
4) Design requirements for external dimensions of batteries: refer to the dimensions of finished batteries
2、 Design scheme for backup lithium battery for portable Bluetooth player:
1) Protection board (PCM): It is mainly designed as a protection circuit for rechargeable lithium battery packs. Due to the chemical characteristics of lithium batteries themselves, it needs to provide intelligent power calculation, overcharge, overdischarge, short circuit, overcurrent and other protection functions to avoid danger such as combustion and explosion.
2) Protection IC: The main protection function chip of the design scheme, which monitors the overcharge, overdischarge, overcurrent, short circuit and other functions of the battery cell in real-time online, ensuring that the battery cell operates within a safe, stable and efficient range.
3) Temperature switch: mainly designed for temperature protection function. When the temperature of the battery itself reaches the range of 70 ± 5 ℃ due to other abnormal issues, the temperature switch will activate to provide temperature protection
4) 18650 lithium-ion battery cell:/ 18650/220mAh/3.7V Li ion cell (Samsung).
5) Field effect transistor (MOSFET): MOSFET transistor plays a switching role in the protection circuit, always ensuring that the voltage across the load does not rise or fall, ensuring voltage stability.
6) Battery packaging: PCV heat shrink
