Overview of the difficulties in the design of power lithium ion batteries for smart wearable devices

Summary of the difficulties in the design of power lithium-ion batteries for smart wearable devices 1. I personally think that the boost method on the market is not good, the power is relatively low, and the power cannot be too large, so the buck method is generally selected. Of course, the most used is LDO. Is it true? Answer: I can’t generalize! The high power of LDO is only when the input and output pressure difference is very small, it is more common to increase the pressure now more than 90% of the power. 2. Please inquire about the balance current of each battery of the lithium battery, and the periphery of the lithium battery How many transistors are generally required? Answer: This is important based on the customer's requirements for the product, but from the cost point of view, there are less than 4 dedicated balances, and the consistency of the battery pack is more important. Regarding multiple batteries, many plans are based on passive equilibrium plans, usually a few milliamps to a dozen milliamps. If there is a large equilibrium demand, the external equilibrium method is required. Whether the balance of demand is important depends on the consistency of the battery and the capacity of the battery. 3. How to allocate work and sleep time? This has a lot to do with the total power consumption. Answer: According to different product functions, different meanings of products and customer experience, the actual situation will be very different. Because during hibernation, some functions will be turned off, may be reduced, and so on. 4. Some charging ports of the bracelet are not unplugged from the USB, and some are charged through contact points. Do you have a more suitable charging port plan? Is it easy to use? Answer: USB charging actually takes up a lot of space, and the contacts are corroded. The best interface is wireless charging, which can be completely sealed, but the overall product planning is more challenging. 5. Is the service life of the battery close? The battery is almost out of power, what kinds of prompts? Answer: The industry has meanings to the battery life, if the capacity decays to 60% of the initial capacity, the prompt part can be done! Then, if you choose TI In the electric energy measurement method, the chip directly supplies the corresponding information. 6. How long is the service life of the button battery in the smart wearable device? Can you replace the battery? Answer: The service life still depends on the total power consumption of the system and the battery capacity. The voltage channel of the button battery is slightly lower, so the boost The demand is slightly higher, and there may be some weak currents on it. Whether the battery can be replaced depends on the ID plan of the entire system. Looking at the application scenario, half a year of use should be no problem. 7. Smart wearable devices have a long battery life. What are your suggestions for the power consumption of this part? A: The battery itself actually consumes very little power. The important hard damage is the relatively small battery capacity and the corresponding total power consumption of the system. Therefore, the space structure has limited the size of the battery, thus limiting the capacity of the battery to extend the use of battery life, only to optimize the power of the entire system as much as possible from the power supply, from the low power consumption mode of each functional module. Smart wearable device power battery planning 8. Will fast charging damage the battery? Answer: Fast charging is important to the battery itself. If the battery is an ordinary battery, fast charging will damage the battery. In addition, even if fast charging is supported, after the battery is aging, continuing to fast charge will accelerate battery aging. 9. What is the charging power of TI's wireless charging plan? Answer: The ability to send or receive a chip can reach 93%. From the transmitting input end to the receiving output end, the total system power is about 75%. 10. What is the method of wireless charging the transmitter? Answer: If only the QI specification is met, TIBQ500212A is widely used. If dual-mode PMA and QI are supported, BQ51222 can be used. If the transmitter is 5W, the best combination of BQ50002A+BQ500511A, 15W can use BQ501210. 11. What is the wireless charging capability of the wearable device? Is there an overheating problem? Answer: The power of our BQ51003 microcontroller is more than 90%, and the entire system The power is around 75%. The heating problem depends on the overall plan, and the important loss lies in the transmission of the coil. 12. For wireless charging of wearable devices, because the transmitting coil must also be small, it cannot be used with standard TX coils. Is it impossible to pass Qi certification? Maybe Qi certification is unnecessary? Answer: TX terminal selection standard, RX receiving terminal can be planned by itself and can pass the standard. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.