How to choose a suitable AFE for BMS lithium battery management system

Lithium batteries have the advantages of small size, high energy density, large output power and no memory effect. In addition to being widely used in Europe and the United States and other places, the utilization rate of the Asian market has also increased rapidly recently. In response to the business opportunity of lithium battery protection chips, the company launched a highly integrated analog front end (AFE) battery controller, which is to conquer the market by reducing the size and simplifying the battery system design. The important standard that BMS can refer to is QC/T897-2011. The most important requirement for AFE is acquisition accuracy. The standard index requirements are not very strict, and the detection conditions are very vague. The latest discussion paper is much better. The measurement and verification of AFE's voltage acquisition accuracy seems simple, but how to implement an accurate voltage reference source, especially in EMC detection, is a question worth discussing. In actual use, we regard the cells connected in parallel as the same cell to sample; further, the cells are basically connected in parallel first and then in series to reduce the demand for sampling channels; but it makes us a headache The thing is, the number of batteries connected in series in a Module is not fixed, and the total number of batteries connected in series is not uniform. In this case, we need to match the number of cells of each module, but the maximum voltage channel number of AFE is a non-continuous distribution, so we must carefully select the appropriate number of channels for matching, so that it is neither waste nor reluctant. . Therefore, especially for third-party independent BMS manufacturers, it is more difficult to make a platform version of the product because of their limited right to speak, sandwiched between the main engine factory and the battery cell factory. Although lithium batteries have many advantages, the potential dangers in their use should not be underestimated, such as being intolerant of overcharge/overdischarge, voltage overload, and must be wary of over-temperature situations. Therefore, a monitoring chip must be added to the design. For protection. In addition, the circuit design of the traditional battery system is quite complicated, which will delay product development to the time to market. In response, a series of highly integrated AFE battery monitors have been introduced to enhance the safety of lithium batteries and simplify the design of the battery system. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete it. Previous: What is the reason for the rise of the lithium battery?