The battery manufacturers provide the specifications of the temperature range. The JEITA profile is a popular charging voltage and current profile depending on the battery temperatures as shown by Figure 4-1. With the integrated temperature profile, there is no need for the host to perform the complicated temperature monitoring and the associated charging current or voltage adjustment. This feature not only helps extend the battery lifetime but also can reduce the charging time for a better customer experience for robotics with a mop function. When the mop is dried with the hot air for 10 to 30 minutes, the ambient temperature of the system is high. The battery charger with temperature profile management can still keep charging the battery within the JEITA profile without sacrificing the battery's lifetime. The overall charging time can be reduced and the customer can have a better user experience. T_COOL has 4 options of [5C, 10C, 15 and 20C], while the T_WARM has 4 options of [40, 45, 50, 55C]. The charger voltage and current have different percentages referring to the regulated values. For example, the I_CHG has 4 options controlled by ISETC[1:0] at T_COOL and has 4 options controlled by ISETH[1:0] at T_WARM. The combinations of I_CHG percentages and the different percentages cover a wide variety of the charging temperate profiles.

The buck-boost charger provides the flexibility to charge the different battery configurations from the different input voltages. The benefit is to have the same adapter for different generations or platforms of vacuum cleaning robots with different battery configurations, cell voltages, and capacities. This can help reduce the R&D cost and total system cost. The long-term benefit is that the standardized USB-PD charging adapters can be adopted as the input charging source, so the cost of the total design can be further reduced. shows the buck-boost charger controller BQ25730.

Figure 4-1 BQ25798 Charging Current Temperature Profile