I remember ZP had the answers. See this:

http://www.mclarenlife.com/forums/mclaren-mp4-12c/66442-my-battery-died-couldn-t-open-door.html

MBG

 

Jesus this car is a pain in the ass if the battery dies.

WTF is the point of the manual locks near the sideblade if they don't work?!

For future reference if anyone has to do this, the trunk wire is literally straight up. It's not deeper in the wheel well like I though it would be, it's like straight up from the edge of the liner, you don't reach in, you reach up.

Hopefully the battery is fine and just can be charged... trickle charger got the juice flowing, so hopefully the battery holds a charge reasonably well still. Fucking power was out here due to a wind storm, killing power to the garage and trapping the car inside it, during which time the battery got too low.

 

power was out here due to a wind storm, killing power to the garage and trapping the car inside it, during which time the battery got too low.

That sucks. How long was the car sitting without the battery being charged? Typically when I park my car the battery monitor advises something like 45 days til dead, but I don't trust that for a moment. I usually plug the charger in if it sits more than a day or two, but yeah, a power outage screws that up...but most outages only last a day or so at the most - unless you are in the boonies? Anyway, interested to hear how long it took for the battery to get into trouble.

 

The battery is weird. I've allowed my car to sit for months without the battery draining more than 5 or 10%, then about two months ago it went to 0% in less than a week. Fortunately there was just enough juice to allow me to open the frunk and plug in the charger. It charged up to 30% within a day, sat at 30-35% for about a week then went all the way up to 100%. It's been sitting off the charger since then and is still at 95% (just checked). I wonder if one of the auxiliary systems was left on somehow... on a few occasions I've locked up the car and seen IRIS still powered on (music playing and everything), had to open it back up and cycle aux power to get everything shut off properly.

 

I wonder if one of the auxiliary systems was left on somehow... on a few occasions I've locked up the car and seen IRIS still powered on (music playing and everything), had to open it back up and cycle aux power to get everything shut off properly.

I drained mine like this one time.

In hindsight, I think I had turned the car back on with a single press of the Start button, foot off the brake. And then left it that way.

British electrics... <sigh>

 

After you insert the key you have to push the door a bit to be able to turn the key.
Just trying to turn the key does usually not work.
Be aware that the door window can crack when you try to open the door.
This is why you should leave the window a bit down when you park your car in your garage.

 

I definitely was shaking the door. The key would turn a little and I can feel something moving inside, but it definitely wasn't opening.

 

careful, don't smash the window! same thing happened to my cousin, he pulled the door and the window imploded...

 

Fortunately the car had automatically lowered the windows. It should do that on every car when the battery gets low specifically for this reason.

 

*runs to garage and checks that trickle charger is plugged in* Phew...

My 12C is a weekend warrior, so I see an average of 1-5% drop in battery per week without charging, sometimes more. The variability is crazy. As such, I leave that thing plugged in at all times when not driving.

 

I never seen my battery go below 100%, even when off the charger for weeks at a time. Makes me wonder if the meter even works. Having said that, my car has now been on my garage lift for about three weeks and hasn't been on the charger. I'm sure I have now jinxed myself and when I get home later the battery will be completely discharged!

One thing I will add though is that it is very easy to THINK you have turned the car off, when in fact it is not. I have found that it's possible to depress the start/stop button long enough to shut off the engine, but not long enough to get the car out of the 'on' mode. For this reason I ALWAYS triple-check the IRIS display to make sure there is nothing besides the clock lit up when exiting the car. I've also found that since my 12C is often finicky about where I keep the key fob (it prefers the space in front of the cupholder*, or the little pocket on the front edge of the drivers seat), that it is easy to forget the key in the car. Mac Philly has told me a few times that it is very bad to leave the key in the car, both for the fob battery and the car battery, so I try to consciously think about the key whenever I'm getting out.

*keeping the key near the cupholder sometimes prompts a warning that I have left the key in the frunk. Anyone else get this?

 

I've been unavoidably gone since September. ( hurricane Irma repair and cleanup) Just got home and checked the 650. Dead battery. Using the key, I carefully opened the door keeping an eye on the glass and helping it move away from the roof line by pulling gently with my finger tips. Opened fine. Opened frunk. Put meter on charging socket. 1.7 volts. Connected charger. Green light blinking on charger. No other lights.

Any ideas on where to go from here?

My plan is:
-let it stay connected like this for a few days, checking on the battery voltage often.
-if that doesn't work, I'm thinking of using a dumb charger, through the socket. Checking the voltage every couple of minutes or so. Hoping to get enough voltage in the battery so the smart charger will recognize it.
-then if that fails, taking out the tub etc.
I will keep everyone updated.

 

I've been unavoidably gone since September. ( hurricane Irma repair and cleanup) Just got home and checked the 650. Dead battery. Using the key, I carefully opened the door keeping an eye on the glass and helping it move away from the roof line. Opened fine. Opened frunk. Put meter on charging socket. 1.7 volts. Connected charger. Green light blinking on charger. No other lights.

Any ideas on where to go from here?

My plan is:
-let it stay connected like this for a few days, checking on the battery voltage often.
-if that doesn't work, I'm thinking of using a dumb charger, through the socket. Checking the voltage every couple of minutes or so. Hoping to get enough voltage in the battery so the smart charger will recognize it.
-then if that fails, taking out the tub etc.
I will keep everyone updated.

First update. Checked CTEK charger manual. Flashing green light indicates the battery itself has gone into UVP under voltage protection that disconnects battery to prevent complete discharge. Says to press RESET for 10 seconds. I pressed and held for 10 seconds. Voila, she came alive! Clicks and groans all over. The window rolled down to where I had it before I left. (oh, it rolled itself completely shutting during my absence)
Now charger lights went to 7, then to 1 with steady green and steady red.
CTEK manual says to press reset again, pressed reset again, nothing. Pressed and held for 10 seconds again. Car came alive again! Charger lights are steady green with 1 and 2 lit, indicating it is charging battery.

 

I saw a video where someone got it going by keep hitting the button over and over from dead till it got a charge.

 

So far sounds like you are going to be fine.

 

Take it out and drive it. let the CPU "see" all of the sensors receiving signals like the wheels are turning, suspension movements, etc. Then after restarting the car many of your warning lights should go off.

 

Ok, thanks Ill give that a try tomorrow.

 

Fourth update: Drove her for about 15 miles. Shifted through all gears and went 65 mph even though dash says in limp mode. All the stalks on column are inoperable. Light switch and mirror control switch not working either. Seems to be in track mode even though dash displays Normal. Powertrain knob works fine but Handling knob doesn't. When I start her up ACTIVE is brightly lit but not the surround ring. When Active is pressed, the surround ring on all 3 knobs brighten. When I touch the Handling knob, they all go dark as if they turned off.
Then she was shut off with foot off brake and locked with key fob.
Sat for about 3 hours.
Drove her again for about 15 miles. All faults still present.
Shut her down as before.
Going to let her rest a while and go check.

Will update.

If faults still there my plan is to drive one more time. See if that does it. If not, call dealership. I'm sure they will tell me to bring her in.

Oh, during shutdown, dash says "ESC Failure Shut Down and Restart". I shut down and restarted 10 times in a row. Still no change.

 

Fifth update: Errors still present. Started. Drove. Shut down as before. Errors still present. Stalks still inoperative,etc.
Does anyone know of Ctl-Alt-Del type reboot? Looks like a cold boot is in her future by disconnecting the battery. Will update.

Oh a new error popped up for a fraction of a second "PCC disconnected".

 

LOL. You're fighting a losing battle. You WILL ultimately end up buying a new battery.

 

I hope you're wrong. If this is the case, can the Lithium battery be replaced with a lead acid one?

 

Also read about what I experienced using a lead acid battery. It cost appox 100.00 (cheap vs the 3,000 battery) to see if you can eliminate some of the crazy errors you have before you toss the old battery out. You will pick up some new "features" until you get back to a original style Lithium-Ion McLaren battery.


http://www.mclarenlife.com/forums/m...m/forums/mclaren-mp4-12c/67434-diy-a123-systems-lithium-ion-battery-repair.html

 

Thanks I will certainly try these. Didn't see these prior threads.
This forum is great. I will keep everyone updated. I saw where NRG on the prior threads had the exact same issue but didn't follow up with the resolution. Bummer.

 

I hope this helps someone in the future. Knowing what I know now, a battery disconnect the first day would have most likely cured it.
One of the reasons I posted my trials was to add to the experience/knowledge base here. Back in the precomputer days, we had absolutely no factory support or instant messaging forums. The best we had were telephones and the monthly newsletter of whatever car club we belonged to or chatting around the bar over drinks at the next meet. Customer service, wasn't even a thought of the manufacturers.
For instance, we, meaning car owners and club members, had a Maserati Information Exchange where we sent part numbers to add to a list of interchangeable parts. When the cars became commodities and not just enthusiast's cars, that all disappeared.
I kind of get that old feeling with the McLaren brand. Little factory support but enthusiastic enthusiasts. A camaraderie. Helping each other.

Hey mothership, join our merry gang, let's chat around the bar and help us in our tribulations. We like you, we really do.

 

Glad to hear you worked it out..

We need to make a master DIY thread on this forum for these common 'issues' / fixes.

 

I have been adding a lot of these to the FAQs, including this fix under 8.0 of the FAQs:
http://www.mclarenlife.com/forums/m...ms/mclaren-lounge/63273-faqs-common-mclaren-questions-problems.html#post1257009

 

Thanks everyone for the help and support. Couldn't have done it without your help.

 

Ok I will check that. Drove some today but didn't notice anything different. I will post back.

 

Just curious, does anyone know the expected life of the lithium battery in our cars is? I've tried to research it but come up short.

 

I just made this post in another thread, but thanks for the info in this one as well. I am going to run the process noted on the CTEK (from pg2 of this thread) and see if that helps or not before fully take the trunk out.

I am dealing with a dead battery in my 2013 12C Spider. I have been in contact with Braille Battery as I ordered a battery through Jeggs that we thought would work as a replacement, however, after talking to them it seems the battery only has 2 posts and the McLaren battery has a 3rd input to control electronics within the car. Braille advised me if I get the battery out of the car, they can refurbish the old battery. See their comments below. I did talk to a contact at a McLaren dealer and he advised for me to check if the tender is bad, then take the trunk out and try to battery pack jump it, if not, it is toast. Keep in mind this car only has 2500 miles and is always on the lithium ion tender when not in use. So at this point, I am sure the battery is toast and needs to be rebuilt or replaced.

("Now, there is one thing about the setup they have in those cars is that there is a plug on the OE battery that communicates with the car and not sure how the car works without that info. Have you heard or read about anyone using a battery other than the original battery and not having the dash board light up or anything like that? Our batteries are all direct replacements to any other “dumb” battery, but not sure how it works in the street car compared to every other car we have our batteries in.

Another option, which we have done several times, is to actually rebuild the OE battery that the customer sends in. We test to make sure the electronics are still good and then put our race pack into the existing case and it can still plug into the car the same as before. This is a $2500 upgrade and would give you more power & capacity than the B128L (because it is larger & heavier), so that may be an option you may want to consider unless you know that the car works fine without being plugged into the battery. I would assume someone on the forums has tried something like that?

If you want to go that route and ship us the stock battery, we can certainly look at going that route. It will take a little longer, but is certain to work. Just an option and somewhat surprised that some of the customers we have done this rebuild for haven’t passed along that option.)

 

Can anyone help out with a similar issue...battery meter shows 0% but car will start (barely) and seems like it still has some juice left. It seems as if it's successfully charging and its been on the charger for 3 days straight now (sitting on step 7 of CTEK charger) but hasn't made any progress..meter still shows 0%

It automatically goes into park, and doesn't let me drive when I try due to the low battery

Any way to get the battery to wakeup properly? Much appreciated

 

I believe there is a way they can try and recondition the battery at the dealership. Not 100% sure as mine was completely dead so I just replaced it.