AtTheGlen

Ditto on thanks to Joan Alcover and to you for the info. When doing the process as you described, do you lock your car upon completion? If so, do you think that is necessary regarding the cars electronics and preventing battery drain?
Thanks!

RCorsa

Well I take it back. Lol. After confirming the battery was charging for about a hour I went back and checked again 2 hours later and the car had disconnected again from the trickle charger.

motown

I am trickling to positive terminal in frunk and grounded to frame. Even after doing so the low battery notification doesn't go away even after two nights of the charger saying fully charged.

Anyone know how to get rid of the annoying notification "Low Battery"????

Joan Alcover

I typically lock the car and have the charging process go well.
There are reports that it works also if you do not lock the car.
My suggestion is to:

1. Charge "locking the car".
2. Once fully charged, redo the process without locking the car and see if it works, too

Joan Alcover

I typically lock the car and have the charging process go well.
There are reports that it works also if you do not lock the car.
My suggestion is to:

1. Charge "locking the car".
2. Once fully charged, redo the process without locking the car and see if it works, too

Joan Alcover

Have you had more success without actually starting the engine?
Have you waited 60 seconds between turning ignition on and connecting charger to mains?
What charger are you using (CTEK, Porsche, other brand)?

ELSE, does the following apply to you (was your battery significantly dischargeed and thus "disconnected" from the car electrical network)?

The CTEK Lithium XS charger has a function to obviate this situation; here is what the user manual says:

BATTERIES WITH "UNDER VOLTAGE PROTECTION" Some Lithium-ion batteries have an on-board UVP (under voltage protection) that disconnects the battery to avoid it becoming too deeply discharged. This prohibits the CTEK charger from detecting that there’s a battery connected. To bypass this, the battery charger needs to open the UVP. By pressing the RESET-button for 10 seconds, the charger opens the UVP. During this process, the charging STEP 7 is lit. Once the UVP has been opened and the battery is ready to be charged, the charger automatically starts the charging cycle.

Similarly, the Porsche Charge-O-Mat user manual says:

BATTERIES WITH "UNDER VOLTAGE PROTECTION"
Some Lithium-ion batteries have an on-board UVP (under voltage
protection) that disconnects a discharged battery. This prohibits the charger
from detecting the battery. To bypass this, the charger needs to deactivate
the UVP.
1. Disconnect the negative terminal of the battery
2. Connect the red and black clamp in accordance with the picture below
3. Connect the charger to the wall socket
4. Select Li-Ion charging program and press the MODE-button for 10
seconds until one of the indication lamps is lit (procedure may be
repeated).

Joan Alcover

Quick question to owners of 992s with a problem linked to:

• Fully discharged battery;
• Trickle charger not remaining connected or not charging the battery

Is you car “North American specs”, “European specs”, “Other region specs”?

RCorsa

My car is a 2021 USA car and I’m using the new Porsche branded charger. When I tried this “workaround” without starting the engine or leaving it on 60 seconds, the car would disconnect from the charger in about 10 min. Using this technique, it was working for well over an hour so I assumed it was all good. However when I went my the car 2 hours later it had disconnected again.

hcvone

Same thing with my car

Formula1Fan

I tried the same thing with car both leaving it connected for 60 seconds in accessory mode and then I tried it with the engine running for 60 seconds. In both instances it disconnected. This is ridiculous!

redyps

As I said in the other thread, I was able to successfully use the accessory plug in the passenger footwell to charge/maintain the battery.
I am using the newest Charge-o-mat Pro.
1) Connected the tender to the wall outlet.
2) Plugged the tender into the accessory plug.
3) Turned the ignition key to on (without starting the car).
4) Pressed mode on the charger to lithium.
5) Turned off the ignition.
6) Locked the car. Charger showed power light, 1/2 battery, lithium.
6b) While detailing the car I did accidentally unlock and relock the car twice - eventually I took the key out of my pocket.
7) After 6-7 hrs only green power light lit. Instruction manual said mode was not selected.
8) Pressed mode on the charger to lithium. Charger showed power light, 3/4 battery, lithium.
9) Left overnight. Tender now in maintenance mode after battery fully charged. Shows power light, full battery in green and lithium.

Formula1Fan

Ok thank you so much I just followed the procedure you outlined. I will get back to you in an hour or so to let you know if it worked.

Formula1Fan

So far so good! It has been around 90 minutes and it is still connected to the battery. It shows 50% battery and hasn't moved since it's been plugged in but at list it's still connected!
Thanks!

redyps

If it shuts off and only shows the green power light lit, just press mode to lithium. Then it should eventually go to battery full green light and enter maintenance mode.

RCorsa

@redyps No dice. Still my car and charger (newest Porsche branded one) shuts down every time. I cycle through the buttons as above and it starts charging (on the third battery icon) and then shuts off after 10 seconds.

It has to be a bug. No way would Porsche designed it this way and still sold owners this trickle charger. Plus its hit or miss that the work around actually works which means its a faulty system.