This IC is used to measure a lot of LiPo or LiIon battery parameters, like charge/discharge current, time to empty/time to full, charge current and so on. It requires a pulse of 21V in order to be programmed to different cell capacities (default is 2000mAh), so the board contains a LM2703 step-up voltage regulator. The whole circuitry of LM2703 including both transistors can be safely removed from the board if you're happy with cell capacity of 2000mAh, just make sure to connect PGM pin to GND in this case. BQ27210 uses I2C bus in order to provide all required data, but BQ27010 can be used with HDQ data bus as well. SHDN pin of LM2703 can be connected to PGM_IN pin so 21V would be available only when it's required to reprogam the BQ27210 IC and LM2703 won't consume any current when BQ27210 is in normal operation mode. Make sure to introduce a small delay between putting PGM_IN high and actual programming in this case as voltage regulator must come up and supply 21V before any programming can be done. PGM_IN should be connected to a MCU controlling this board and communicating to BQ27210 via I2C bus. When PGM_IN is high - 21V is applied to PGM pin of BQ27210 allowing to program it. By default PGM_IN should be zero and even if left floating - it would be pulled down to GND. This board doesn't have any pull-up resistors for I2C bus so this should be taken care of on MCU side.