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Ok, so here is the mystery. The McLaren Jumper shows that the battery is like half full. What the heck? Why would the car go dead if the battery is half full?

What’s weirder still. The car still won’t start. It normally starts with way less charge showing there.

I’m going to assume it’s just inaccurate from the jump and give it a few more hours.
Haha, go and have a beer and leave it overnight before you touch it!
 

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Last time I had a dead-dead battery (my commuter car) it took the CTEK a while to charge it. It goes through all sorts of weird stuff. Much easier when it’s used as just a tender. Good luck though I’m sure it’ll be fine once you get it hooked up.
I've had a similar experience with CTEK. They're good at maintaining, but not so good at recovering a really dead battery. The battery on our 3 week old Outback died overnight a few weeks ago and the CTEK would start charging and then crap out. It took my old charger to get it going up to 9V, at which point the CTEK would work and eventually got it to where it would crank. If I had to replace the CTEK, I would go with Sean's suggestion instead.
 

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Discussion Starter · #43 ·
I agree that you should assume that it is inaccurate and that it goes through a bunch of weird cycles (designed for battery maintenance). Interestingly, the ctek manual says to hold the reset button for 10 seconds to bypass the Under Voltage Protection, so maybe the 5 seconds in the McLaren manual isn't quite long enough. Hopefully all is well in a few hours.
I tried the 10 second thing too. No love. :(
 

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So I'm realizing I lied to all of you. I said I didn't drive for like 3 weeks but realize about 9 days ago I went out to meet a friend and took the Macca. So it had been driven not too long ago.

And when we went out, I noticed something strange that I dismissed (and should not have), when I parked and locked the door, I notice IRIS was still on. Why? And once it happened in the garage. So maybe there is some phantom thing keeping things on in the car? I havent done anything new with the car, other than I guess I am using my iPhone 14 now, but cant see why that would keep things awake (and I do not leave it in the car).

Strange.
Yeah, that doesn't sound good. My Iris sometimes goes off when I stop the engine, but sometimes not until I lock it, but after locking it's always off.
 
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I think the CTEK connector is proprietary, you might need a Noco specific one for the cigarette lighter connection. It's trivial to unfasten the panel though and connect straight to the battery.
Know how I know you've never done anything with a P11 platform car? You remove half the frunk to get to the battery, after you've also taken out a trim panel with 5 screws in it (after #1,000 or so), 7 more screws, 2 hex bolts, 10 plastic screw pins, frunk carpet, and both cargo nets.
Thanks! Will the NOCO work directly plugged on the battery leads, worst case?
Yes.
Ok, so here is the mystery. The McLaren Jumper shows that the battery is like half full. What the heck? Why would the car go dead if the battery is half full?

What’s weirder still. The car still won’t start. It normally starts with way less charge showing there.

I’m going to assume it’s just inaccurate from the jump and give it a few more hours.
Never trust the level on the charger. My car if the battery is low (or even charged on charger then taken off) may not show full but driving it makes it go up 1% per minute regardless. Leave it overnight and it will start, if it's flat dead it will take several hours before it will start. Attempting to start it before then could knock the battery out again AND cause various lights to come on including but not limited to the airbag.
So I'm realizing I lied to all of you. I said I didn't drive for like 3 weeks but realize about 9 days ago I went out to meet a friend and took the Macca. So it had been driven not too long ago.

And when we went out, I noticed something strange that I dismissed (and should not have), when I parked and locked the door, I notice IRIS was still on. Why? And once it happened in the garage. So maybe there is some phantom thing keeping things on in the car? I havent done anything new with the car, other than I guess I am using my iPhone 14 now, but cant see why that would keep things awake (and I do not leave it in the car).

Strange.
Do you have anything plugged into the OBD2 port? That'll do it. But, from time to time IRIS likes to stay on for no reason in these cars. Typically it shuts off after 15 minutes, or when you lock it.
 
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The really weird thing is that the same thing happened to my phone at the same time as my car!! 😭 I shattered the rear cover, and I changed it a couple of weeks ago. Just before I fitted the new cover I tried to power the phone on and got nothing! Plugged it in and it started charging but I had no way to get it to start the boot sequence. I spent a week messing with it, not wanting to give up on it (it's a fantastic phone, Xiaomi Mi 9 Pro with 12gb of RAM and 512GB of internal storage). Eventually, I disconnected the battery from the motherboard, then held the wireless charging coil against the charger while plugging in the USB cable, and it booted! The second time I tried, it didn't work, it started booting then died. I had to lightly hold the battery connector to the motherboard, so the phone thought the battery was at 15% (it was actually at 100%), then once it booted, I pushed the connector into place. It works fine now, I just can't power it off!
 

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Know how I know you've never done anything with a P11 platform car? You remove half the frunk to get to the battery, after you've also taken out a trim panel with 5 screws in it (after #1,000 or so), 7 more screws, 2 hex bolts, 10 plastic screw pins, frunk carpet, and both cargo nets.
Haha! One more reason to upgrade to a 570!🤪
 
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So woke up today, charger light is in the green. Knock wood. Have to do somethings out on the ranch today, will come back later in afternoon and hopefully she'll start up.

Thanks everyone! Will report back how it goes.
No one is going to be able to sleep tonight if you don’t tell us it started ….. 😃
 

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Discussion Starter · #53 · (Edited)
better to start the car before re-assembly
I did and it wont start. So the car when I get it in looks dead. When I push the start/stop button it lights up red, but nothing else lights and pushing it seems to do nothing? Yes I'm mashing the brake and btw, the brake pedal seems to be kind of pre-mashed a bit when I push on it, if that makes any sense.

Should I unplug the battery and let the car reset and hook it back up again? If so, I'll have to try that tomorrow afternoon, although maybe I could close the garage door, that might not be bad for 5 minutes. I forget, do I have to pull both leads off for the reset?

But while the charger seemingly has charged the battery, the car is no bueno. :(
 

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I did and it wont start. So the car when I get it in looks dead. When I push the start/stop button it lights up red, but nothing else lights and pushing it seems to do nothing? Yes I'm mashing the brake and btw, the brake pedal seems to be kind of pre-mashed a bit when I push on it, if that makes any sense.

Should I unplug the battery and let the car reset and hook it back up again? If so, I'll have to try that tomorrow afternoon, although maybe I could close the garage door, that might not be bad for 5 minutes. I forget, do I have to pull both leads off for the reset?

But while the charger seemingly has charged the battery, the car is no bueno. :(
Yes, disconnect the negative lead on the left.
 

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Discussion Starter · #57 ·
GOT IT TO START! W00000T!

Ok, so I left the door open with a towel by the lock so it wouldn't lock while it was charging and not working. I never closed the door. I, thankfully and accidentally let the door close, cursed as I approached it to see if it would open. IT DID. and once it did the interior came to life. Then, when I hit start button, it started right up!

So I guess for whatever reason, if the door was up while the battery was dead, and you never close it, the computer for some reason stays dead/dormant. You have to risk closing the door at some point and that helps the car 'reset'.
 

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Discussion Starter · #59 ·
Took the car out to get some icecream. Was fine. Had to reset the date/time (it was set to 1970! and 2008 simultaneously somehow). After that was like nothing happened.

In retrospect it seems like iris and stuff not turning fully off clearly killed the battery extra hard for I don’t know what reason. Weird.

Thanks again everyone!
 
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