I intend to use BQ25751 to charge 2x12V SLA battery connected in series.
Hence Vnominal = 2x12V = 24V, Vbat_absorb = 2x14.4V = 28.8V
Q1. When determine what resistor divider values (Rtop, Rbot) for the FB pin, the VBATREG in the Rbot formula (see datasheet pg59) should be Vnominal or Vbat_absorb?
If VBATREG = Vnominal = 24V, the BQ25751 boost mechanism will automatically increase the charging voltage to 28.8V when enter absorb-charge phase?
Q2. How is the REG0x16_Three-Stage_Charge_Control Register affect the charging voltage?
To charge the 2x12V with Vbat_absorb 28.8V, besides configure the resistor divider mentioned in Q1 correctly, I believe VBAT_ASORB bits in this register should also be configured correctly. Shall I configure the bits to 11b such that the chip will provide Vabsorb 28.8V and Vfloat 26.4V or if I wish to get Vabsorb 28.8V but Vfloat 27.3V then the bits should be set to 01b ?
