My daf would drain batteries until I fitted an isolator. I’m guessing the reason it’s gone down this time is that it’s been left for about 6 weeks over Xmas and whilst recovering from the dreaded virus.It's an Iveco. That's a factory fit feature.
I'm fed up dealing with Iveco's and batteries that go flat. I can't even remember the last time I had to deal with battery drain problems, but the past couple months I've had to deal with 3 Daily's with battery drain problems.