Other Parts Discussed in Thread: BQ25892
Hi.
My company uses the BQ25896 to charge the battery of a commercial product. In general we find it works very well, however we have identified some issues with the handling when a battery is very flat.
In some cases the users of our equipment leave the power switched on for a long time, causing the battery to deeply discharge. Usually the 25896 low voltage cutoff functions and prevents any further discharge.
However we have observed that if the battery does discharge too far, its own protection circuit activates and the battery voltage then goes to 0.
Once this occurs, the BQ25896 appears to use a very low maximum current on the system rail. It is not enough current to boot the rest of our product, so it sits at some low voltage (like 1.8 volts) and the product cannot be recovered. The only way to recover is to either:
a) disconnect some internal parts to lighten the load on the system rail, or
b) remove the battery and charge it on some other charger, enough to get the battery protection circuit to reset, and then return it to the product
Both options are difficult for the user.
The data sheet says "Instant-on Works with No Battery or Deeply Discharged Battery." I can't find any mention of the low current limit when the battery is disconnected/reading 0 volts.
Please advise what we are missing, and what we can do to fix this.
Thanks.
