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Q:
Why does my bq24650 not charge?
A:
As explained on page 18 of the datasheet, the TS pin must be at a voltage between VREF and GND in order for the IC to charge. For example, the EVM resistor divider for the TS pin, with JP1 shunt set to EXTERNAL, is expecting a 10k battery-pack thermistor connected in parallel with the bottom feedback resistor. By moving the JP1 shunt to internal, an on-board 10k resistor simulates this thermistor.
As explained on pages 12-13, the MPPSET pin must be at a voltage above 1.2V but less than 5V in order for the IC to charge. For example, the EVM resistor divider for MPPSET is set so that the IC will not charge unless the input voltage is above 21V. You can either change the resistor divider or apply an external voltage directly to the MPPSET pin.