BudFox6

Update: Three weeks after I made my 28 Dec 22 post, the battery again died. The battery maintainer had been plugged into the footwell the entire time. Go figure. I recharged the battery at the battery posts and had no further problems as I drove the car every other day. I heard that keeping the car locked will shut off some of the electric circuits and can help prevent battery drainage. The only problem with locking the car is the hassle of using the emergency key to get the car opened with a dead battery.

In the meantime, I won't have battery problems for a while, as I traded the car into the dealer yesterday for a Turbo S I ordered thirteen months ago.

Coolwnc

I guess we will pickup another Rennlist member after the car is purchased by another person at the dealer.

Fullyield

Which is why I lock the car with my windows down when in my garage.

siberian

With all due respect, whether the car is locked or unlocked the receiver module is still going to wait for a signal. Could the seat sensing program also be in receive mode? Could there be as was mentioned above, an issue with the Gateway module? This BMS system is a mess and clearly not ready for prime time is a 160k+ vehicle has to be tethered every second it's not driven.

siberian

gcurnew

I have a 2020 C4 with the lithium battery and no discharging issues (I'd knock on Paldao wood if I had it, but alas I have the "base interior lol). Perhaps what I DON'T have and use on my car might be relevant. I don't have Porsche Connect set up (dealer couldn't get it working after 4 tries), so it's possible there's no ongoing polling of vehicle status or no reporting going on that causes a current draw? Maybe a shot in the dark but Porsche doesn't appear to have any better ideas.

siberian

Escalating this up to Porsche NA.

I don't have Porsche connect, I'm not sure I have the issue, but I have only one dealer in the State that refuses to perform the update (whether Bulletin #2229 solves the problem or not is unclear) but I'm not ready to risk being stranded so every second the car isn't driven it's on a charger (which I don't believe is healthy but I don't care for the alternative).

This BMS system is a mess due to the interrelated nature of this nightmare. I've passed this thread on to Porsche NA in the hopes that some light may be shed as keeping my car tethered in fear that if not I'm going to end up with a $170k paperweight is not the experience I expect.

siberian

BondJ

^^^Good call.

Guys, if you can, I recommend plugging the maintainer from mains direct to the battery. The accessory port can be unreliable. Also, attach live and ground. This ensures the BMS is kept in the loop when charging. Also, use the maintainer regularly, regardless (respectfully) of whether you feel you should have to or not. Do this and, at worst, you’ll have a data point

siberian

Again this is a band aid for cancer. A car of this cost and prestige should not have to be plugged in the second it's not driven. But given the FUD surrounding this, we've become so paranoid that this is the only solution. Porsche needs to solve this and fast.

siberian

BondJ

Completely agree. I only suggest a “Band Aid” is preferable to a “170k paperweight”. Porsche should be embarrassed it has not addressed this problem

aggie57

and the reality is they know how to, and do it when you complain enough. My car gets way less use now that I have my Polestar, it's been 3 months since it was 'fixed', and never sees any sort of maintainer. Starts every time now, like it did for the 2 years before the problems started.

Motorin Mark

When you say "fixed" what exactly was the problem and what exactly is the fix?

Fullyield

Well, Porsche fixed it in MY 2022 and PCM 6. Is the disconnect between the factory and the dealers in the field maybe?

siberian

The fix in Bulletin #2229 applies only to 2020 and 2021 PCM5 992s with CCU software version other than 0420. If there is an issue with 2022s that also had a battery issue this means the issue is still not solved or PCM6 brought other bugs into the mix. Not sure if @aggie57 car falls into the 2020-2021 mix and what was done to it.

siberian

aggie57

It's documented earlier in this thread but basically after two years of reliable starting out of the blue my battery died, was replaced under warranty, died again twice and spend a couple of weeks at the dealer who applied some patches, reloaded and reset several modules, and that's about it. I 'think' they applied the TSB @siberian has identified but the language on the service reports wasn't clear on that. For me the biggest change I can see (apart from it starting reliably) is that now I consistently see 14.2 - 14.5 volts rather than oscillating between that and low 13's. I have an AGM battery.

Either way, I consistently took the view - and still do - that the situation was unacceptable and it was their problem to fix.

siberian

Thanks for clarifying. Although the patch applies to both AGM and LiFePO4 it's good to know what was done to both. Thanks for clarifying

siberian