SLYT803B october   2020  – october 2020 BQ24610 , BQ25713 , BQ25790 , LM66100 , LM74700-Q1

 

  1.   1
  2. 1 Introduction
  3. 2 Understanding Battery Packs
  4. 3 Stackability Requirements for Battery Packs
  5. 4 A Multibattery Management System Design
  6. 5 Battery Charging
  7. 6 Battery Gauging and Protection
  8. 7 DC-to-DC Converter or Controller Stage (Boost or Buck-boost Stage)
  9. 8 ORing Control
  10. 9 Load Sharing
  11. 10Conclusion
  12. 11References
  13. 12Related Web Sites

4 A Multibattery Management System Design

A multibattery management system that can share the load accurately makes it easier to stack batteries. For example, a 4S4P Li-ion battery pack has four parallel paths, and each of those paths has four series cells.

Table 1 lists the specifications for a multibattery management system.

Table 1 Basic Specifications for 4S4P Battery-management System
Specification Value
Battery chemistry Li-ion
Cell voltage 3.6 V to 4.2 V (when fully charged)
Battery configuration 4S4P
Maximum pack voltage 14.4 V to 16.8 V (when fully charged)
Input voltage of the system 12 V or 24 V (sometimes with a 19-V laptop charger used as the input)
Output voltage of the system 12 V or 24 V

Figure 2 shows a multibattery system with five stages: battery charging, battery gauging and protection, DC-to-DC converter or controller stage, ORing control, and load sharing.