Here's an interesting thing that I will report after taking mine in for a suspected bad battery this week at a new dealer. (I've dealt with my prior dealer since 1990, but have since moved, and although I wouldn't say they were perfect they knew me, and would work with me without trying any funny business. However, they are now 30+ minutes away, and I have 2 dealers within 10 minutes from me now, so I figured I would see how one of these dealers is.)
Although the service advisor tried to get me to pay a diagnostic fee and upsell me on some "semi-annual" service package, that all went away when I said that the battery was replaced in November 2019 at another dealer, and I'm fully covered by a Gold Plan after my current basic warranty runs out. (This was despite the fact that he had the VIP report in his hands that shows this, and could see the last service visits at the other dealer) He then proceeded to call the other dealer and ask for them to send over a copy of the invoice where it was replaced under warranty. Once he had that, the semi-annual service package wasn't mentioned again. Super sketchy IMO.
Anyways, they hooked it up to the GR8 battery tester and all is well apparently with the battery. Then I noticed in the tech notes that they disconnected and reconnected my IBS. Prior to this service visit I was seeing weird things with the charging voltage, 14.4 or 14.5 while running, and below 12V on ESS restarts. Ever since the IBS reset, it's been charging at 14.0 and restarts have been above 12.X. He also proceeded to read me the list of ESS conditions from the owners manual that would prevent it from activating, even though I've told him that it's consistently been a "battery charging" message for the past several months.
All in all, I'm not sure I will go back to this new dealer, but maybe he is new, as he had to ask the lady at the desk next to him how to even enter the issue in his work order system.
I'm thinking the IBS may be some of my issue and it wasn't fully tested in the past? Perhaps I will try disconnecting and reconnecting the IBS in the future if this ever happens again?
I'm keeping my battery on a trickle charger since it's not being used that much now so we'll see what happens.