[David D]

My battery went flat in my garage, I leave it connected to a trickle charger but while on holiday builders unplugged the charger to use the mains but forgot to plug it back in. Fortunately the bonnet was open so I connected my standard Halfords charger and an hour later the car started and off I went to work.

Later that day when I went to start the car there was not enough power in the battery. Work to home is only 1 mile. I could not get into the bonnet as it is electrically locked so I called Porsche recovery, they sent the AA who used a power pack to put current through the terminal on the fuse board. The bonnet did not open but various lights came on around the car.

Eventually the car had to be lifted onto a truck and taken back to Porsche at Colchester. They say that as I connected a charger to the battery terminals I voided my warranty and caused £1800 worth of damage to the cars electrical system.

Has anyone else had similar problems

 

[Nosmo]

You might also want to ask the question here: https://www.porscheclubgb.com/forum/tm.aspx?m=978299



Sorry to hear about your troubles though.

 

[Porsche2018]

Has anyone else had similar problems .

Sorry also to hear about your difficulty I guess it was related to not having the Porsche trickle charger plugged in. I was completely unaware of this issue thanks for the heads-up. I have used the trickle chargers quite often on my Porsches and other cars without an issue. I went to Colorado for a two month vacation and kept the 718 on the charger the entire time without issue upon return.
What specifically was electrical damage to your 718?

 

[Semitone]

Something certainly doesn't sound right about this.

First, provided the charger was in proper working condition, I wouldn't expect the charge regimen to be substantially different than if you jump started the car and then recharged the system with car's alternator/voltage regulator system. Unless the battery was faulty, I don't see why this would do any damage to your car. Normally the battery will just refuse to hold a charge. Lots of people jumpstart cars a few times only to find out that the battery is just at the end of it's life.

Second, the manual says to do exactly what it sounds like you did:

Page 65 | 2017-2018 718 Cayman Manual | Porsche iManuals

I don't know what to say except my nose is acting up.

(EDIT: I see you only charged the battery for an hour. That doesn't sound like it is long enough to properly charge a battery, particularly if it is in a severely discharged state. Sure it started you car but that was probably all it could do. The one mile drive then did nothing to help the situation so finding the battery failed to start the car a second time is what I would expect. Nothing about that scenario is suspect to me.)

 

[Viffermike]

@David D : First off, welcome to the forum.

Also: I had to edit your thread title to more accurately reflect your issue and concerns. I know it's not easy when you're frustrated, but please do your best to not let those frustrations color statements of fact.

Now: No 'trickle' charger is going to charge a battery in 1 hour. Similarly, 1-mile trips are not going to be sufficient to keep the car's battery charged (much less your engine in top shape since it never warms up to operating temp ... but that's another issue). Also: As outside temperatures go down, your car battery's ability to store current goes down.

Furthermore, you mentioned using a 'standard' charger. I took a peek at Halfords chargers; there are many models, so I have no idea what you mean by 'standard'. To wit: Porsches (and most modern cars with complex electronics) do not use 'standard' lead-acid batteries. You need to make sure you have a trickle charger appropriate for the car -- generally a 'smart' charger that can handle AGM-type automotive batteries. My advice would be to read this thread in the Engine and Technical Discussion subforum, or purchase the Porsche Tequipment smart charger from a dealer.

Based on your driving habits, you do need a trickle charger, but you need the right one -- and you need to have reasonable expectations regarding what it can do.

 

[don]

I wouldn't have thought a battery charger could damage your electrical system?

I agree with above, if your battery was flat then one hour of charging is not going to charge it. It will take at least a day. In fact if you always do short trips your AGM battery will never fully charge. I try to give ours a routine once per month full charge (see photo below).

Also the newer CTEK charges (which I understand is the Porsche labeled one) has an AGM setting for the special stop/start battery that your car should have. The charge voltage is slightly different.

Also if it was dead flat it probably wont fully charge on the normal setting, the charger will think the battery is dead. So you will need to click the Recondition button on the CTEK charger to bring it back to life. I've had to do this before on my normal Ca battery.

For those who are interested I just found this description on the 8 CTEK charging stages:
http://blog.streetsideauto.com/auto-parts/8-stages-ctek-battery-charger/

 

[JazzCatGab]

I'm thinking of getting the CTEK charger and want to plug it into the car from outside the car (as I've read they can get pretty hot). Is there a good, and handy to use, way of routing the wires from the positive/negative charging points for the battery to the outside of the car, or do you need to open the fronk and plug in there?

 

[JakiChan]

I have the Porsche one (rebranded CTEK) because it was the easiest to get, but oddly enough Suncoast sells the cables to hook directly to the battery from the Porsche charger.

The battery in my truck ran flat and it’s an AGM. It took my Schumacher charger a LONG time to charge that thing up to full. (My truck battery is pretty big and it was completely dead, but still.)

 

[don]

I'm thinking of getting the CTEK charger and want to plug it into the car from outside the car (as I've read they can get pretty hot). Is there a good, and handy to use, way of routing the wires from the positive/negative charging points for the battery to the outside of the car, or do you need to open the fronk and plug in there?

If you do a search people have been using the cigarette lighter plug adapter and running the cable out through the door:

https://www.ctek.com/products/vehicle/connect-cig-plug

 

[greywing]

The Porsche charger comes with the cigarette lighter plug as seen in the configurator.

 

[Veets]

+1

Been using a CTEK plugged into the cigarette lighter for many years to keep the battery topped up when the car is stored for winter.

 

[JazzCatGab]

Thanks folks. I guess the cigarette lighter would be the easiest solution, if you could find a plug in the vehicle. I won't have the ash tray and cigarette lighter option. In the online manual, it looks like only USB connections in the center arm rest and glove box. Where else might one be? Also, in the manual, the only charging option it lists is in the battery compartment where clamps are supposed to go on the positive pole and the negative ground ball (not the post). This may be an easier question to answer when I get the car and can look at what connections are available.

 

[CaymanMatt]

Thanks folks. I guess the cigarette lighter would be the easiest solution, if you could find a plug in the vehicle. I won't have the ash tray and cigarette lighter option. In the online manual, it looks like only USB connections in the center arm rest and glove box. Where else might one be? Also, in the manual, the only charging option it lists is in the battery compartment where clamps are supposed to go on the positive pole and the negative ground ball (not the post). This may be an easier question to answer when I get the car and can look at what connections are available.

Look in the passenger footwell.

 

[Viffermike]

Look in the passenger footwell.

Yep: This.

Also, @JazzCatGab : Your car will have 'remote' battery connections in the frunk; those are what you should use with a trickle charger in lieu of connecting directly to the battery itself. I'm personally skeptical of using a 12v socket to recharge, especially in the winter -- I guess I'm old-school that way, LOL.

One way to 'pass the time' while you're waiting for your car to arrive: read the online Owners Manual here. It'll have answers to a lot of questions you surely have about how the car is set up and operates. >

 

[greywing]

Not sure what your reluctance to use of the 12V socket is Viffer. The trickle charge is by definition low current while maintaining the battery. I personally don't like having to leave the frunk lid open for long term inviting unwelcome visitors. When the battery is flat different story and of course would be shorter term connection. Of course, just another opinion.

 

[CaymanMatt]

Not sure what your reluctance to use of the 12V socket is Viffer. The trickle charge is by definition low current while maintaining the battery. I personally don't like having to leave the frunk lid open for long term inviting unwelcome visitors. When the battery is flat different story and of course would be shorter term connection. Of course, just another opinion.

Why leave the frunk open? I connect directly to the battery, add the extension from CTEK, run it out from under the panel, down the side next to the frunk opening, and then carefully close the hood where it will not pinch the cable - basically in the bumper region. I've considered leaving the frunk half open though and may consider that down the road. For now though, I see nothing wrong with this scenario. Nothing is being pinched & no paint is being rubbed.

Question for Viffer though: I read the manual and looked for the remote battery terminals. The negative remote terminal is easy to find! I could not find the positive remote terminal. The graphic in the manual isn't exactly clear on this location. Presuming both these lugs are there, how do you then connect the charger lugs to those remote terminals?

Thanks!

 

[Viffermike]

Why leave the frunk open?

Precisely; you don't have to at all. The only part of the frunk area that weather-seals is the luggage area; the rest is not sealed. You can connect a trickle charger and close/lock the frunk completely.

@greywing: Call me skeptical of a socket that's originally designed only to supply current one way. Yes, low voltages can be fed in the opposite direction through it, but IMHO, the electrical system is simply too delicate and not designed to accommodate that long-term -- and most smart chargers have the capability to produce higher-amperage current in certain situations (i.e., battery reconditioning). Besides: you still have to plug the charger in somewhere, so you're going to be running a wire from inside the car to outside of it anyway ...

EDIT: Per the post by @JazzCatGab below, it appears that maintenance charging via 12V socket is recommended by Porsche (I'd forgotten about that page in the Owners Manual, too). So I stand corrected ... and I need to grab a 12V adapter for my CTEK.

Question for Viffer though: I read the manual and looked for the remote battery terminals. The negative remote terminal is easy to find! I could not find the positive remote terminal. The graphic in the manual isn't exactly clear on this location. Presuming both these lugs are there, how do you then connect the charger lugs to those remote terminals?

IIRC, it's under a hinged plastic cover that pops up when access to the terminal is needed. Maybe someone can post a photo?

 

[JazzCatGab]

Folks, thanks again for the information and opinions.

For whatever reason, this page in the 2017-2018 online manual eluded me:
Page 101 | 2017-2018 718 Cayman Manual | Porsche iManuals

Why leave the frunk open? I connect directly to the battery, add the extension from CTEK, run it out from under the panel, down the side next to the frunk opening, and then carefully close the hood where it will not pinch the cable - basically in the bumper region. I've considered leaving the frunk half open though and may consider that down the road. For now though, I see nothing wrong with this scenario. Nothing is being pinched & no paint is being rubbed.

This sounds reasonable to me CaymanMatt. On the stock post clamps on the battery, are there places to attach the supplied CTEK attachment, or do you have to buy and add something? I like the idea of adding the extension and then plugging the charger in outside of the vehicle because I may have a way of programming the charging if we have a cold and long winter.

 

[CaymanMatt]

Folks, thanks again for the information and opinions.

For whatever reason, this page in the 2017-2018 online manual eluded me:
Page 101 | 2017-2018 718 Cayman Manual | Porsche iManuals





This sounds reasonable to me CaymanMatt. On the stock post clamps on the battery, are there places to attach the supplied CTEK attachment, or do you have to buy and add something? I like the idea of adding the extension and then plugging the charger in outside of the vehicle because I may have a way of programming the charging if we have a cold and long winter.

I just took a few photos of my setup. I'll hope the attachment works.
There is no "remote" positive hookup, only the negative as shown in the photo, but there are a couple bolts that I plan to piggyback onto. I currently have the positive connection on the positive terminal bolt & the negative connection clamped between the battery post & the terminal - something I don't like. I will add a piggyback washer/nut setup for both to the extra threaded section of the terminal bolts.
Good luck!

Edited: I now see that the remote positive terminal in the owners manual is ... just the positive terminal of the battery. Makes sense of course but their graphic was confusing.

Anyway, the cable connection from the battery is not long enough to escape the plastic lid covering that area. I tried to bring it out near the windshield but didn't like the feeling that the cable was getting pinched - even if it was between plastic pieces. The current connection underneath the panel is fine since its not accessed very often. I'll see if I can add a better photo later.

 

[Speedy69]

I am putting my Porsche 718 boxster gts in the garage for the winter, most probably until mid to end of March, I have a Porsche charger with a cigarette plug.
Is it ok to have the charger connected all that time, or is it better to connect the charger e.g. a day per week ?
thanks