gcurnew

Good info, thanks. Presumably the wireless jump start couldn't be made to work with the OE Porsche lithium battery?

tcirillo

does anyone happne to know if the typical smart "battery tender' (brand name) is acceptable for lithium batteries? secondly (i take delivery in a few wks), does porsche supply a battery tender/charger with the car? thanks

tcirillo

just found this: "Here is the simple answer: A Battery Tender® can not measure State of Charge (SoC) of a lithium battery. It simply does not have this capability. While they work great on lead acid batteries, they are not able to accurately “read” lithium batteries. So, they will never properly charge a lightweight lithium battery.

G650

Thanks for this Info. I’m reluctant to leave the car unlocked, as it’s in a common area (But secured) garage. May consider disabling the alarm system when I leave on an extended trip. I do recall there being a way to do this.

tcirillo

does porsche supply a battery tender/charger with the car?

eagle1960

No.

Antigravity

A couple things with this is that a lot of the newer models will have jump start points or terminals as opposed to the battery directly being connected but the other more important thing to note on the Porsche lithium batteries is that I believe according to their instructions they state jump starting is not allowed on their battery. You may want to confirm this but always best to go by what their instructions/manual say when using their battery.

jcw0322

Same thing happened to me on my 2020 C2S with RAS late summer. Found out the car was totally dead and after only 10 days of no driving. Luckily the car was not locked so getting into it was easy. I got a lawn mower battery and used it to open the frunk. There is an emergency pin/terminal in the driver side fuse box as shown in owners manual for getting the frunk open in cases like this, Extending the pin for this and connecting the pin to positive, then negative to the door hinge got the open frunk button to work. . I then removed the plastic cover over the battery and jumped the car as per manual. I drove it for 30+ minutes. The car started fine after that. Ironically, I had a C-tek L-ion charger for the car had but never used since I was driving it somewhat regularly. On first attempt the C-tek charger would not connect and charge to the battery via the passenger foot well socket. So I went through many threads here and found that if I plugged in the charger to the foot well socket, STARTED the car and THEN plugged the charge into 110v outlet, it would recognize the charger and work. So 12+ hours later I had a fully charged battery all good according to the charger lights. A dealer check out of the battery gave it an OK. I have not had a problem since. Possibly I left something on, I don't know and didn't see anything. My previous 2014 C2S would regularly sit for about 5 weeks between starts when I was traveling often and it always started. That 2014 model had the OEM battery and was in it until the car went away in 2019.

user 64927802

This is a great idea

CodyBigdog

I realize this is an older thread, but recently decided to “trickle-charge” my 992. I have the RAS option on my car, so presume I have the Li battery (although have not verified). In any event, a few weeks ago I broke down and bought the battery tender at Porsche. It has the specific Li mode that you can select. So I followed their instructions, which were simple enough:

(1) Plug in the cigarette lighter plug (from the tender) into the outlet found in the passenger foot well. Close the passenger door and “lock the car” (interesting that the instructions tell you to “lock the door”? I assume because of not locked, there are measurable current drain with some (active) systems in the car...or for theft reasons? Very odd.

(2) Next plug in the tender to the AC outlet.

(3) tap the “mode” button until the Li mode is selected.

I noticed that the battery status indicator did not light up, so re-read their instructions, and found that since my car had not been started for more than 30 minutes prior to starting the trickle-charge, the power port in the footwell was deactivated...so, instructed to:

(4) Turn the ignition on and then off.

(5) Now the battery indicator is on, and it reads about half charged....which surprised me that it was that low?

I currently have about 750 miles on the car, over a period of about 45 days. I typically drive it every 2-3 days, for about 20-30 miles....so the car isn’t sitting in my garage for long periods of time. I also lock my car after driving.

After about an hour, it is still charging and still sitting at half charged, so it appears the cigarette socket has not timed out? One final note: The tender is warm to the touch. I can still hold it in my hands, but noticeably warm.

digits

You had to turn on the ignition (accessories only) to power up the footwell socket after the car was off for a while. If your charger is still lighting up one of the LEDs for charge level after a half hour or so, then it's working. Congrats !

I could never find a way to get either of my Porsche branded charge-o-mat pro chargers to work with the footwell socket in my particular 992 (2021 TTS) - it would always shutdown in less than 30 mins (locked/unlocked/igition on for 5 minutes before locking/etc). The CTEK Lithium US charger has been working well for me, though.

Cornishman

As a data point, I just left my 992 (warm climate, no rear axle steering) for five weeks, locked, with no charger. It fired right up afterwards with the volt meter showing 14.5v

K-Nut

same issue, connected charger directly to battery and it shoot down after full charge with only i blinking
charger is specific to lithium battery in my GT3
i assuming the charger shoots down after battery full

Richard_Wallace

There is a sequence you need to do to keep the 12V internal socket active:

Try this and it will stay active, and charger will continue to work and not shut down:

Procedure to keep 12v internal socket active:
Connect your charger to the 12v socket - Car ignition off, Charger NOT plugged into the wall. Make sure the cigarette adapter is well seeded, I push it in and spin it a bit to make sure it is connected well.
Charger connected to the 12v socket - Car ignition on, plug in (turn on) charger. (The car can be running or just powered on - I typically just turn the started one spot to activate the electronics.
Press mode to make sure you are on Lithium or whatever your car has (on the charge-o-mat from porsche hit mode 2 times for lithium batteries)
Check lights on charger are on step 1/2/3 etc. It will likely be on step 2 for a while and then goes to step 3. Wait about 1 minute or so with your car power on and the charger plugged in.
Turn ignition off - Charger lights should still be lit. You are good to go and the 12v socket should now stay live.

Joan Alcover

Good to go only if you lock the car!