[piran]

Under power the CGTS frame-less window latches into the roof lining gutter. How does one get the window to drop clear of the roof after a completely dead battery?

From the manual I see that the emergency key (contained in the fob) can be used to mechanically open the door lock but how to drop the window first? Is there some sort of notch or detente in the unlatching mechanism that allows the glass to drop enough to clear the window (unpowered)? Is it then just a case of rubber gloves and a lot of 'persuasion'?

I get the front fuse box re-powering exercise (to release the bonnet solenoid and access the dead battery) but not how the window is simultaneously released.

Perhaps the OS is designed to hold enough juice in a dying battery situation specifically to drop the window glass?

Maybe there's a 'golden capacitor' installed for that very job?

...or the old fashioned way with GBH / blunt force trauma / smashing the window?

 

[jimmuller]

Under power the CGTS frame-less window latches into the roof lining gutter. How does one get the window to drop clear of the roof after a completely dead battery?

I think it is a matter of persuasion. Once this past winter my windows were frozen shut. When I hit the Unlock button on my key fob the passenger's window started trying to go down but couldn't. As it didn't stop trying I figured that wasn't a good state to ignore. So I just pulled on the door handle. The window popped out of the rubber seal and door opened just fine.

You might want to check with your dealer or service department. I'm sure they can give you a more legitimate answer.

 

[RussellHodgson]

In my previous 986 and 987 I've had dead batteries at one point or another. In both cases when the battery gets low enough that it becomes likely that you won't be able to start the car, then windows automatically move down into their door open position. So the concern you have is alleviated that way. I assume the 718 is the same.

 

[piran]

So... a programmed preemptive drop down ...a fail-safe as it were?

 

[piran]

Time passes ...my thread continued - in a slightly different vein.

Whilst still self-educating myself on the vagaries of the operation of the car (a polite way of saying the given documentation is not particularly brilliant or fully fit-for-purpose) I ignored several power downs the OS enforced whilst parked up with the engine off but ignition on. FWIW this car really appears to use up battery power quite a bit more than any vehicle that I've ever operated. Quite caught me unaware - hence the addition to this thread so as to caution others:-/

Returning to the car several days later there was enough in the battery to allow me to open the driver's door lock which appropriately dropped its window. However, when I tried to start the engine, strange things happened. No matter how I attempted to turn the engine over the OS just oscillated between the dashboard showing me seemingly random errors then blanking out. This was repeated at about one second intervals even when it should've been cranking the engine over. At no point was there any indication that the engine would actually be turned over. Just the above dashboard display chaos and then blanking - all repeated at intervals.

Back in olden days (I'm ancient) eg with dynamo generators (not alternators) and dashboard incandescent bulbs (not LEDs) one could see a lighting level degradation up on the dashboard or interior lighting as the power drain bottomed out the now inadequate battery (during cranking). Nowadays digital/binary seems to rule - it works or it does not. Seemingly my car was now stuck in a narrow window in between those scenarios.

An unassisted successful start really was not probable. Whilst the battery had enough in it to fire the solenoid I released the froot to at least ensure access to the battery. Ignoring a recent hernia operation :-| to lift down and drag over to the garage a trusty decades old (previously trolley mounted) charger ...a legendary Clarke. This had to be lifted into the froot so as to be closer to the battery - there being no other access in the confines of my garage.

Mindful of the showroom's technician's advice (during handover whilst answering some of my too-technical questions for the sales team) I connected the Clarke to the prominent earthing post (NOT the negative terminal of the battery) and the battery positive. Potential differences and high circulating currents otherwise possible could conceivably blow some sensitive circuits (apparently). Always connect jump start stuff to the dedicated earthing post.

Whilst I held down the Clarke's manual/boost override my wife operated the ignition. My Porsche 718 Cayman GTS immediately fired up with its customary roar. Job done.

Not wanting this to happen again and, more mindful of the hernia aspect, I now have a more modern smaller Lithium-ION charger which I keep in its case out of sight in the void behind and slightly under the driver's seat. The case is nicely designed and I believe well worth the small extra cost. I hope this stuff will prove up to the task if/when required... the specs would suggest that it should be so capable.

Anyone used this stuff in real life?

[ jump start kit - circa UKP160 ]
NOCO Boost HD GB70 2000 Amp 12-Volt UltraSafe Portable Lithium Car Battery Jump Starter Pack for Up to 8 Petrol and 6-Liter Diesel Engines

[ case for the jump start kit - circa UKP20 ]
NOCO GBC014 Boost HD EVA Protection Case

Mindful of the usual copyright issues I have not re-used the pictures on Amazon (though I can't think that they would mind) and supplied a home-grown 'unboxing' image which I hope will suffice for any interested forum members.

[ declaration ]
I have no commercial or other connection with anything specified in this post nor do I expect any remuneration of any kind though I do own and run the Porsche so mentioned ...which plainly could do with a bigger battery by design ...or a better manual;-)

 

[DriveInHouston]

These Li-ion starters/storage batteries are incredible! I jump started my Mustang's V8 after a 4 montth hiatus that I couldn't drive a stick due to a dislocated shoulder! What made it more incredible was the fact that I hadn't charged the little battery for a year and it jump started the V8 with 2/5 indicator lights on!!...

Took the same brick to a week long bicycle trip in Holland to be the backup to the mobile phone (using the RidewGPS app with pre-defined daily rides).

Very useful little device, we have two!

 

[jimmuller]

Mindful of the showroom's technician's advice (during handover whilst answering some of my too-technical questions for the sales team) I connected the Clarke to the prominent earthing post (NOT the negative terminal of the battery) and the battery positive. Potential differences and high circulating currents otherwise possible could conceivably blow some sensitive circuits (apparently). Always connect jump start stuff to the dedicated earthing post.
...
Not wanting this to happen again and, more mindful of the hernia aspect, I now have a more modern smaller Lithium-ION charger which I keep in its case out of sight in the void behind and slightly under the driver's seat. The case is nicely designed and I believe well worth the small extra cost. I hope this stuff will prove up to the task if/when required... the specs would suggest that it should be so capable.

Anyone used this stuff in real life?

I have a portable battery unit with a small lead-acid battery inside and recharging circuitry. I have used it for years for starting various cars, with a Slime pump to fill bicycle tires to 140psi, and with an inverter as a portable device to run a 120v 60 watt light. Never needed it on the Cayman. Have replaced the internal battery twice. My neighbor bought a lithium-ion emergency starter battery, smaller and lighter than mine. He has used it successfully and likes it.

The caution against using the negative pole on the battery has been around for a long time. It isn't really to protect the electronics. Unless there is an active power moderating element between the battery and the frame ground, very very ulikely, it will make no difference to the electronics. In fact to charge a battery your external device would have to provide a bigger potential difference than the battery itself, so "forcing" it into the frame ground doesn't protect anything. Anyway, you can test this with voltmeter. You should find no voltage difference between battery post and frame ground, regardless of whether the engine is running.

The real reason to use the ground post is to avoid a possible explosion. Given sufficient reverse, i.e. charging, current a battery can release hydrogen gas. In an open air it generally disperses quickly but could possibly collect around the battery in a confined space. When you detach a cable it creates a spark. By using the ground post far away from the battery itself and always detaching it before detaching the positive cable, you remove the spark from the vicinity of any hydrogen. Otherwise you have a small-scale Mark Watney experience.

 

[tekart]

I have a portable battery unit with a small lead-acid battery inside and recharging circuitry. I have used it for years for starting various cars, with a Slime pump to fill bicycle tires to 140psi, and with an inverter as a portable device to run a 120v 60 watt light. Never needed it on the Cayman. Have replaced the internal battery twice. My neighbor bought a lithium-ion emergency starter battery, smaller and lighter than mine. He has used it successfully and likes it.

The caution against using the negative pole on the battery has been around for a long time. It isn't really to protect the electronics. Unless there is an active power moderating element between the battery and the frame ground, very very ulikely, it will make no difference to the electronics. In fact to charge a battery your external device would have to provide a bigger potential difference than the battery itself, so "forcing" it into the frame ground doesn't protect anything. Anyway, you can test this with voltmeter. You should find no voltage difference between battery post and frame ground, regardless of whether the engine is running.

The real reason to use the ground post is to avoid a possible explosion. Given sufficient reverse, i.e. charging, current a battery can release hydrogen gas. In an open air it generally disperses quickly but could possibly collect around the battery in a confined space. When you detach a cable it creates a spark. By using the ground post far away from the battery itself and always detaching it before detaching the positive cable, you remove the spark from the vicinity of any hydrogen. Otherwise you have a small-scale Mark Watney experience.

On the 718 there is a battery monitoring system, so if you go directly to the negative terminal you are bypassing the shunt and whatever else is sitting between the battery and chassis. Porsche specifically says to use a chassis ground for this reason, and there is a tab right next to the battery for this. Also no issues really with hydrogen since the factory battery is AGM vs flooded lead acid... it can vent gas, but there wouldn't be any meaningful amounts especially under normal conditions.