@Landshark
That is an interesting question and hypothesis... I don't know, and am not 100% certain I understand your statement/question. Are you not using Hondalink? Never activated it with a Honda account/VIN etc?
If that is the case, based on what I observed today, I would completely agree with you. That may greatly reduce your vehicle's standby power use. I activated mine, never really thought about it as I know the vehicle TCU sends Honda all kinds of info anyway. I wanted the long range climate and power state info. Of course, later I find I don't use it as much as I initially thought I would. The Clarity definitely "calls home (Honda)" when it is first turned on, turned off, and anytime it begins or ends a charging cycle (there is a minimum time limit I think, of 10 or more minutes between scheduled automatic "calls"). As to the data that is being sent, I am still digging through that. This is part of Wiresharking that I am still learning, with a layer of Fiddler running on top, and well, let's just say I need to watch more youtube instructional videos. I think the panda may be an easier solution, but that is more coding making my head explode. We can assume they know everything, and Hondalink tells us just a few variable.
I do
not believe that "not activating" Hondalink turns the info Honda itself can get remotely from the car off. However, it would effectively eliminate "owner" information requests (pings), and that would reduce load, maybe substantially. If Landshark's long term storage success ends up being a rarity compared to others, this may be a real thing. Since most apps on phones run in the background (unless you specifically turn that service off), and can update in the background (ie, send a request for status/data to your car without you asking) it is
possible that just having HondaLink installed on your phone and activated (enabled) can cause info requests you did not actually initiate.
I haven't seen the source code so this is speculation! However, based on a hack report I read on Nissan regarding the LEAF and remote feature servers for their phone app, this is not that far out in left field for a possibility.
I don't want to create a panic situation about Hondalink and this 12 volt draining behavior. We need more data, and this kind of data would require a current logger and, although I have one - I am really not looking forward to doing that (it is a data feed, and boring as hell). We would be looking for needles in a haystack of where your phone requested an update in the background, and we knew it wasn't Honda. I am continuously annoyed with any developer, OEM, etc when they put out a software update (mostly for mobile devices, but even in general) and just say "Bug fixes and performance improvements..." in the version description. This goes back to "Right to Repair" stuff, as without a change log you are in the blind. It is possible that if this is the case, it may get fixed, either on the car via software bulletin - or your phone via an app update (assuming you do it or it is auto).
That is, of course, assuming this is a real issue and not a figment of my imagination....
The bottom line is that the TCU is the tattle tree for Honda and the Clarity is talking a lot. I keep my cars a long time, and as someone who once manufactured a tech device, I understand the warranty-telemetry deal. However, once my warranty is up, I am pulling the TCU cable, and the black box FCAN as well. No, I don't have that little insurance snitch device plugged into my OBDII port or on my phone either. Everyone here knows my driving would exclude me from any discounts anyway! I am also becoming less concerned about the TCU/AT&T 3G obsolescence deal the more I think about it.... but I will have to think about it...
Cheers,
Cash