BQ77915: UV Recovery - solution found

Tool/software:

Hi Guys,

I'm guessing there's no reply to my post because this question has been asked dozens of times before ( original post )

There is no Ti approved solution - but i've found something that works for me

Context :

1. I use BQ77915 to make 4S 100A BMS for stationary storage - 12V 100Ah LFP battery with 12V 1kVA inverter ( 230V output )
2. Mains power goes out
3. Inverter backup is turned ON
4. Battery is used up
5. BMS shuts down from UV fault
6. Mains power comes back
7. Inverter turns ON and tries to read battery voltage
8. Battery voltage read as 0V due to UV Lockout
9. Inverter assumes no battery present
10. Charging doesn't turn ON
11. Battery unable to recover from UV fault

My crude solution :

I use a 4S 1A charger ( 14.6V charger ) in parallel with the inverter

How it works :

1. Mains power comes back
2. 4S 1A Charger turns ON
3. 14.6V is supplied to the DC link between battery and inverter
4. Two things happen simultaneously - Inverter detects voltage and starts charging the battery with 8A - BMS recovers from UV fault after sensing charger voltage
5. Battery charges normally - UV Lockout no longer an issue

Diagram :

P.S : If there's something wrong with my solution, do let me know in the replies. I've tested this out practically and it works for me ( especially with the charger costing around 10 USD )

Hope this helps someone,

Muki