SLUUC54C February 2020 – March 2024 BQ27Z558 , BQ27Z561 , BQ27Z561-R2
The BQ27Z561-R2 updates the no-load full capacity (QMax) when two open circuit voltage (OCV) readings are taken. These OCV readings are taken when the battery is in RELAX mode before and after a minimum charge or discharge activity. A relaxed state is achieved if the battery voltage has a dV/dt of < 1 µV/s. Typically, it can take up to two hours after charging and five hours after discharging to ensure that the dV/dt condition is satisfied. If five hours are exceeded, a reading is taken even if the dV/dt condition was not satisfied. This relaxed cell state is indicated when the [REST] flag is set.