Hello, I have been having starting problems for the past 6 or so months, what happens is it cranks for a few seconds and doesn’t start, and then I’ll crank it again and it’ll either start up or sometimes will require a jump and will come on with a ECP light that will turn right off after turning the car on and off with cables still on. I have a brand new alternator, and have been through 3 new batteries. Putting a new battery stops the problem for a few days until it comes right back every time. Alternator change did nothing. Brand new spark plugs and coils as well.. No engine lights and 112K miles.. any ideas? Thanks

Battery ended up reading over 250°, running at a fire hazard it was burning holes through the carpet in the trunk. Audi mentioned something about the battery interrupter possibly being bad, but wanted $500 for a further inspection.