Does having weaker car battery (soon to be replaced) affect dpf regens in any way? aka will the car not do any regens if the battery is not at its full charge?

I don't know the answer, but I think it is unlikely.

Cannot see how a weak battery would have an affect on the ecu decision to implement a regen. Although stories on Briskoda suggest the ecu can select the most inconvenient time to do one.

Stop/start activation would obviously be affected.

Recently, my Scout went in for a service.  One of the notes I had for the dealer was stop/start wasn't working as well as I thought it ought to.

 

They found two dead cells in the battery so replaced it.

 

Afterwards, I noticed that from around two to three DPF regens per week, it's now down to one a fortnight.  (I cover around 500 miles a week.)

 

Logically I can think of no reason for this - perhaps it was the service, but it does seem to be a bit of a coincidence that, since the battery has been changed, regens have become significantly less.