SLUAAX5 August   2024 BQ25750 , BQ40Z80 , MSPM0L1306

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2The Role of MCU in Smart Battery System
  6. 3Application Example Using BQ25750, BQ40z80, and MSPM0L1306
    1. 3.1 Gauge Setup
    2. 3.2 Charger Setup
    3. 3.3 MCU Setup
    4. 3.4 Communication Protocol
    5. 3.5 MCU Code Example
    6. 3.6 Data Collected
  7. 4Summary
  8. 5References

3.1 Gauge Setup

The gauge was set up such that using advanced charging algorithm and that the charging profile is similar to Figure 3-1.


Charging Profile Using Advanced Charging Algorithm

Figure 3-1 Charging Profile Using Advanced Charging Algorithm

The thresholds for each parameter within constant current (CC) mode, constant voltage (CV), and pre-charge can be modified following The Advanced Charge Algorithm Application Report. The parameters for this example were chosen for the sole purpose of clear transitions in the charging profile. The gauge is connected to a 6S4P Li-on battery.

Although BQ40z80 offers much more options, these are the simplified settings relevant for the application note and validate the charging profile. These settings are for each cell in the pack; there is another setting for the number of cells in series is programmed.

Table 3-1 Simplified Gauge Settings
Standard High Temp Charging Value Units
Max charge voltage 4100 mV
Low voltage threshold 2900 mV
Medium voltage threshold 3600 mV
High voltage threshold 3900 mV
Current at low voltage 1750 mA
Current at medium voltage 2250 mA
Current at high voltage 2100 mA
Termination current 300 mA