SLUUC37C july 2019 – august 2023 BQ75614-Q1 , BQ79616 , BQ79616-Q1 , BQ79656-Q1
Figure 3-1 shows the system block diagram.
The BMS system is designed to prolong the useful life of lithium-ion cells in battery packs through passive balancing, and provide enhanced SOC and SOH measurements using integrated current sense measurement. The device can monitor a battery pack which contains up to 16 cells, or up to 14 cells with the ability to measure fuse and relay voltages. This system monitors voltages of individual battery cells and dissipates individual cell voltages through the use of internal cell balancing FETs. The BMS allows battery-powered electric machines to use smaller battery packs and fewer charging cycles to perform the same amount of work. The BMS also improves the overall lifetime of Li-ion battery packs by preventing undervoltage and overvoltage damage from occurring.
The typical BMS system with integrated current sense has two main sub-systems, as shown in Figure 3-1:
All commands and data are communicated with a host through UART. The BQ75614-Q1 remains idle until a command is received from the host. The BQ75614EVM can support a host PC or microcontroller (via the UART connection header).
The typical flow is for the host to go through the following simplified sequence:
As a single standalone board, the BQ75614EVM can passively balance up to 16 cells, up to 80 V of total voltage. Communication to the BQ75614EVM is handled by the UART host interface.