Hello,
How can I skip the first two steps of trickle charge and pre-charge and start battery charging with the third fast charge step? If it's doable, could you provide me with the way to do it?
Best regards,
Shinichi Yokota
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Hello,
How can I skip the first two steps of trickle charge and pre-charge and start battery charging with the third fast charge step? If it's doable, could you provide me with the way to do it?
Best regards,
Shinichi Yokota
Hi Shinichi Yokota,
The device will start charging in the fast charge phase when VBAT > VBAT_LOWV threshold. If battery voltage measured through the feedback resistor divider is below VBAT_LOWV then the device will start charge in either trickle charge or pre-charge phase. There is no way to skip these phases when a battery is deeply discharged.
If you wish to avoid charging in pre-charge step you will want to design the system to prevent battery from discharging below VBAT_LOWV threshold (approx. 2.85V for a battery being charged to 4.2V).
Best Regards,
Garrett
Garrett,
If I modify the schematic so that the VBAT is kept above the VBAT_LOWV, does it work as intended?
Best regards,
Shinichi Yokota
Hi Shinichi,
Yes if you make your design so that VBAT does not reduce below VBAT_LOWV the BQ25306 will begin the charge cycle in fast charge step.
Mind you I am not quite sure what schematic change you are trying to show above in red. To prevent VBAT dropping below VBAT_LOWV I recommend using a protection IC to prevent battery from discharging too low.
Best Regards,
Garrett