[Porsche Wolfe]

Has anyone use a Porsche battery charger connected to 12 volt accessory outlet on Cayman 718.
I have the 12 volt outlet located on the left passenger side under the glove compartment. Will it trickle charge when plug in to the 12 volt outlet for long-term duration or connect directly to battery. Please advice before I purchase the charger. Thx

 

[grasmere]

Mmm perfect re-cycling?

no, with the engine NOT running the battery would become discharged charging itself, WITH the engine running the car will be charging the battery anyway.

But buy one anyway and read other threads as to why you should

 

[Barryng]

Has anyone use a Porsche battery charger connected to 12 volt accessory outlet on Cayman 718.
I have the 12 volt outlet located on the left passenger side under the glove compartment. Will it trickle charge when plug in to the 12 volt outlet for long-term duration or connect directly to battery. Please advice before I purchase the charger. Thx

If I understand the question, it might be a very good question. Is the question asking if one plugs the output of a low current trickle charger (somestimes call a "battery tender") into the cigarette lighter socket next to the glove box will it charge the battery? If this is the question, I think it is a good question for two reasons. Since it seems every bit of electrical equipment is, in one way or another, controlled by solid state components, will it be able to drive current all the way to the battery? Second, is it safe to do or can you damage any of the electronics.

In the good old days of relays, plugging a 12 V source into a cigarette lighter would have an unimpeded path to the battery. Wires and relay contacts do not care about the direction of current flow, solid state components care a lot. There was no danger for low trickle currents to damage relay contacts and it was generally possible to keep the limited electronics energized if changing the battery. Solid state components typically only pass current in one direction and can be easily fried if the voltage and/or current exceeds their rating.

I would like to understand if this will work because, in the case of a dead battery, it will allow access to the battery if one can back feed a cigarette lighter outlet to energize the cars electrical system so the front and rear trunks can be opened.

 

[Big Benny]

I charge my battery once a month using a smart charger. I attached a short fused lead to the battery positive and the ground point, and the end of that lead has an Anderson powerpole fitting on it, and I have it cable tied to one of the vent slots in the plastic cover over the battery area. It is idiot proof with the powerpole connector fitting, and I open the Frunk, plug in the charger, close the frunk onto the first safety latch, and wait about 6 hours. Now...why did I not simply use the charger plugged into the cigarette lighter at the rear of the centre console ( I have the smoking pack, but don't smoke...it was optioned by the Dealership as they think that it finishes off the console better than without ). I rang the Dealership and asked if I could charge the battery through that 12V socket. They did not sound really sure, but eventually, after asking someone, said " Yep ". Well, I discovered that the socket has power on it for a timed period after you turn the car off ( I plug my crash Camera into that socket ). I don't know if you can still charge the battery through that socket or the one in the passenger footwell...it seemed unlikely to me if the power is removed by the car after a timed period, presumably to stop any attachments left plugged in from discharging the battery.....so, that is why I went the route I did using a lead direct onto the battery positive and the ground point ( NOT the negative terminal ).

 

[Box2112]

You should actually be able to charge through either. I use a CTEK through the 12V adapter in the "smokers package" in the center console with no issues. When it's receiving power it stays active.

 

[Big Benny]

Box2112 has answered the question. After discovering that the power was timed in " normal " operation, I simply took the easy way out...direct to the battery, and the car doors stay closed. I was going to plug a charger into the cigarette socket and see what happened but never got around to doing so. It is reasonable to assume, and Box2112 has provided the answer, that the car senses external power has been applied to the car via that socket or the passenger footwell socket.

I did notice that at the Dealership that most of the stock 911's on the floor, had a smart charger under the car, and a lead into the cabin. What stopped me from going that route, was the less than affirmative reply from the Dealership when I asked, and the ease with which you can get to the battery...so I went with the lead straight to the battery.

When I go in for my first service, I'll be careful to explain what the lead is..and also advise that the soundactor fuse has been pulled.

 

[Box2112]

Its pretty interesting that they didn't know, given the "Porsche" charger (which is simply a rebranded CTEK) comes only with the 12V "cigarette lighter" connection as opposed to clamps....

Makes one wonder...

And actually, beyond the "Porsche Tax" for their branded charger, its realistically less flexible as I'm pretty sure that the 12V connector is hardwired vs the ability to swap between connectors on the CTEK version. I have the 12V, clamp, and the Hopkins adapters (to connect to previous Battery Tender pigtails I already had installed on the motorcycle)... CTEK is a great unit.

 

[Big Benny]

I agree...I was a bit taken back when my simply query required several people to be asked. I come from an electronics background, and could accept that the car was smart enough to detect an external voltage had been applied to the cigarette lighter plug, but as the car was brand new, and not wanting to have any drama, it was easier to remove the car from the equation and go straight to the battery...although using the Porsche advised ground point and not the negative terminal of the battery tells me that the battery management system is still in the " loop ", so it will sense current inflow. I was also happier to have the cabin doors shut...we have lots of creepy crawly things here in Queensland, so I did not want to run into an asian skink ( lizard ), huntsman ( spider ) or snake ( most are dangerous ) in the cabin.

Slightly off topic, my previous car was an Audi RS3. I removed the AGM battery that lived in the boot, and replaced it with a Lithium model . It saved near 20kg in weight, but the car and the battery did not get along. The Lithium battery had an internal battery management module and the car had its own battery management module. The internal battery one to limit charge and discharge current, and to disconnect the battery if the volts went too low. For reasons we could not work out, the car would sometimes not allow the charge system to charge the battery...and I had two instances where the car would not start, and I had to use the emergency button on the battery ( separate cell pack for emergency starts ). I discovered that the cars charging system was not charging the battery....removed it an put the AGM back...all problems gone. I see Porsche specify AGM only for the 718, so what was once a simply system, is not so simple anymore !

 

[jimmuller]

Does not the Good To Know Manual (which in any other language is called the Owner's Manual) describe using the socket in the passenger footwell? I haven't looked in a while because I don't need to worry about it very often, but I think it does. That stuff is "good to know" for a reason. RTFM.

 

[Big Benny]

I did refer to both the Good to Know manual and the manual that came with the car...and was still not clear on the correct procedure, so rang the Dealership. And as I posted above, they were not 100% sure till they found their " battery Guy ". I always RTFM...saves lots of embarrassment later . Rather than risk damaging things, I used a method I knew could not do any harm, and after my RS3 experience, I also knew that what was once a simple system was now somewhat more complicated with " Battery Management Modules" and frame negative and not battery post negative..that alone tells you things.

 

[danchee]

The batteries in our cars are AGM type right? Not the "normal" or pricey LiPoFE4 correct?

 

[Box2112]

AGM, correct.

The batteries in our cars are AGM type right? Not the "normal" or pricey LiPoFE4 correct?

 

[grasmere]

Ah, I misunderstood the ops question, apologies.

answer is yes and has been answered numerous times already in previous threads which included where to run the lead from the 12 passenger well socket and answer is under the closed door where the rubber seal won’t harm it.

 

[Cap]

... I removed the AGM battery that lived in the boot, and replaced it with a Lithium model . It saved near 20kg in weight, but the car and the battery did not get along. ...

I would be interested to hear more from other members about replacement batteries. I recall This Thread from member Krauty357 about using a brand of lithium replacement battery called "Antigravity." Apparently it worked fine, but we don't know if there were any opportunities to fail as described by Big Benny.

I have heard good things about Antigravity batteries. They certainly are much lighter. One concern I have is that I live in a place that can get very cold in the winter, and my understanding is that lithium batteries don't function well in cold temperatures.

Cap

 

[Box2112]

Personal opinion based on what I know is that if you drive the car enough, or use a charger (CTEK or similar) when your car is in storage, there isn't enough benefit (IMO) to justify the cost of moving to a lithium battery at this time.

If you're shaving ounces off the car all over for race purposes, that's a different use case, but for everyday driving, presently, AGM is the better value assuming you keep it at / above 75% charged consistently either through use or charging...


They do have a very low self drain, which is great, but that only comes into play if its not connected in the vehicle, any parasitic drain will still occur so those benefits are really lost on us.

That said, if you're really that worried about weight, or just want the shiniest new thing nobody will ever know is there... Then it should be plug and play with a good battery (such as Antigravity), they are built to basically be indistinguishable to the car from AGM from the perspective of the car's battery management system. I do believe you still need a specific charger that can handle lithium though.

 

[MarkYorks]

I bought the CT5 Ctek Stop/Start battery charge and Cig lead on Amazon last night which arrived this morning even though I am not a Prime subscriber. Have just plugged it into the footwell socket and is now charging. I had the ignition on when I plugged the changer into the socket so hopefully the socket will remain live. Will keep an eye on it tonight to check that it remains live and charging.
This is what I bought:

 

[danchee]

I find little value in switching to Lithium batteries unless you are really looking to shave weight. Compared to AGM, the F80 M3 battery I had was about 1/3 lighter (by arm weighing scale) but it costs $2300 to replace and requires a visit to the dealer to pair the battery to the charging system because they build their own battery management system onto the battery thus available only from BMW. At that price, I could replace 5 AGM batteries and still have change left over so the Lithium longevity really doesn't play into my calculations at all. I'd rather spend that money on driving instructions which would improve my lap times way way more than shaving off a couple of pounds which I could do by dieting which also saves money !

Lithium charges at different voltage than Normal and AGM batteries. The Noco charger I bought have specific settings for each battery type thus my question earlier. On the BMW, you have to charge using the jump start hot point in the engine compartment and never connect to the battery directly. The reason being the jump start connector is connected to the onboard charging system so it can track voltage and lifespan of the battery. If you charge the battery directly, the system won't know how full the battery is and could overcharge it later. PITA really.

 

[jimmuller]

They do have a very low self drain, which is great, but that only comes into play if its not connected in the vehicle, any parasitic drain will still occur so those benefits are really lost on us.

Exactly. The slow drain by always-on circuitry in the car will continue even if the battery has no self-drain at all.

Lithium batteries are discussed at length in RV forums because anyone camping off-grid with no electric hookup has to run entirely on batteries, possibly with solar cell recharging. Lithuim batteries tolerate being discharged much deeper without damage than even deep-cycle lead-acid batteries of any desgin (traditional or AGM). L-A batteries do not like being run dead asnd may not be recoverable afterwards. Lithium batteries will not take a charge when colder than 32F but some have built-in heater elements to solve this issue, though at the cost of a tiny amount of the stored energy. The charging and maintenance profile is similar to AGM, I think, though perhaps not. I never pay that much attention because I have no intention of buying a lithium battery any time soon for any application that uses any L-A type.

 

[MarkYorks]

The footwell socket has stayed live. Been charging now for a couple of hours with my new Ctek charger.

 

[JazzCatGab]

The footwell socket has stayed live. Been charging now for a couple of hours with my new Ctek charger.

Assuming you turned off the ignition. I've never turned mine on to start and it just stays on full time. Also, hadn't seen that version of the CTEK, so let us know how it does.