718 Cayman Trickle Charging Advice

[SK555]

After a fair few “Battery Protection Active During Parking” messages and a few instances of the passenger mirror not unfolding when the car is unlocked I have thought about getting a trickle charger.

I know there seems to be mixed advice about using the 12v socket in the passenger footwell but it seems to be the no faff option.

Question I have is I use the car 1/2 times a week - so how long/often/when should I be trickle charging? Surely unless it’s always on it won’t be benefitting the battery?

Open to advice!

[SV_WDC]

The battery basically shouldn't be getting a deep discharge so how often it needs to be charged also depends on what sort of use it is getting when you are using it.

But for simplicity maybe just plug it into the trickle charger when you're not using it?

[Voodoo Blue]

I've got a 718 Boxster and generally stick it on the trickle charger if it's not going to be used for a couple of weeks or more. I use the cigarette adaptor in the passenger footwell and haven't had any issues with that providing the plug is correctly inserted and always check the unit to make sure its working properly a day or so after setting it up just to make sure.

If you're using it a couple of times a week there is a possibility that any reduction in battery capacity may not recover if the car is only being used for short journeys especially in winter so that might be an indication of why you're getting the error messages unless you have a voltage leak somewhere. Or your battery might just be going bad.

Edited by Voodoo Blue on Sunday 18th January 17:23

[Panamax]

You don't need a trickle charger, you need a new battery.

[Redline88]

I put my GT4 on a charge every few weeks if I m not using it. I don t have power in the garage so need to use a portable power pack but that tends to take it back up to 100% within around 10-12 hours.

Before I started doing that; I would get the same message as you if it was left for around 4 weeks but no problems if left for less time than that. I don t bother if it s going to be used within a couple of weeks

ETA - I use the 12v socket in the centre console

[SK555]

Panamax said:

You don't need a trickle charger, you need a new battery.

I was hoping this wouldn’t be the case - I assume a new battery will need to be coded?

[mikef]

I only have a problem with battery drain in winter partly because of not driving my Cayman for longer periods and partly because of sub-zero temperatures in an unheated garage

In winter I use a wall-mounted CTEK charger, the same model that Porsche used to rebrand and sell at an extortionate price. I attach a CTEK eyelet connector to the battery that is accessible from the middle of the windscreen and can be tucked inside by opening the bonnet. Then attach a long CTEK cable to charge in the garage with a large Remove before Flight banner attached so I don’t jump in and drive off with it still connected (duh)

It takes seconds to connect or disconnect the charger

ps: for ease of detaching the connector from the battery when needed, I used tinsnips to convert the eyelets

[SV_WDC]

SK555 said:

Panamax said:

You don't need a trickle charger, you need a new battery.

I was hoping this wouldn t be the case - I assume a new battery will need to be coded?

It should be coded, yes.

But labour at an indie should be 30mins max

[Snowy999]

You can extend the wires of a CTEK adaptor so that it can be tucked away where the screen wash filler is and keep your battery in great shape and it is invisible when you are driving and safe as CTEK's charger lead is fused and has weather protection on its plug end.

If you don't fancy doing it an Indy will set you up.

[Panamax]

SK555 said:

I assume a new battery will need to be coded?

If you install a new battery of electrical specification identical to the old one you don't need any coding. The charging system will learn what it needs to do.

[PetrolHeadPete]

Panamax said:

If you install a new battery of electrical specification identical to the old one you don't need any coding. The charging system will learn what it needs to do.

My experience too Got one idential to existing fit and it all just worked

[jeebsy]

you don't need to code the battery, the new one will work fine, but it's generally felt the new battery will last longer and perform better if you do code it in. all coding it does it tell the car there's a new battery fitted essentially so the energy management system takes that into account when charging. coders v non-coders is a longstanding debate on the vag forums though.

Edited by jeebsy on Wednesday 21st January 10:48

[Panamax]

jeebsy said:

it's generally felt the new battery will last longer and perform better if you do code it in.

I've done quite a bit of research and found no evidence that coding is necessary where the new battery is of identical specification. The charging system will take a short while to learn that the new battery behaves a little differently from the old one but the system will learn and adjust.

The principal part of coding is to tell the charging system the electrical specification of the battery, which means not just its size and voltage but the specific type (wet or AGM), capacity and CCA. If the new battery is identical to the old one then none of this will be different and there are no changes to be made.

The other part of coding is to tell the system the battery is new. However, this is where the learning ability of the system comes to the aid of a DIY replacement. In normal life a car will sometimes be used on a daily basis so each time you get in and start the engine the battery is already fully charged and the charging system behaves accordingly. Then you go off on holiday for three weeks or leave your P&J parked-up for a month in winter and the next time you start the car the battery is significantly discharged. The charging system recognises this and adjusts its charging accordingly. It's this self-adjustment which similarly reacts to replacement of the battery with an identical battery. After all, not all new batteries are identical - one might be straight from the factory while another has been sitting on a shelf for six months. It's the identical electrical specification that is essential here.

Sure, it's never wrong to code a new battery. I don't bother and the cars work fine. My normal routine is to DIY replace batteries on a precautionary basis when they're 5 or 6 years old, which gives plenty of time to organise an identical replacement from Tayna at a price which substantially undercuts dealers or emergency services.

There's some useful discussion of the coding process from about 5 minutes into this video,
https://www.youtube.com/watch?v=TFK0JPs6aO0&t=...

[jimbo761]

Panamax said:

I've done quite a bit of research and found no evidence that coding is necessary where the new battery is of identical specification. The charging system will take a short while to learn that the new battery behaves a little differently from the old one but the system will learn and adjust.

Would agree with this- I changed the battery myself without coding as all the dealers were closed during covid. No issues with the 'new' one to date which has lasted longer than the old one did.

[DJMC]

My CTEK MXS5.0 charger gave up after around 6yrs and I replaced it with one of these:
https://www.toolstation.com/ring-smart-battery-cha...

Better display, no 12v socket option, but I used the supplied ring connectors to fix the bullet cable to the battery, bought a bullet cover off ebay, and tuck this in to the tyre inflator storage box under the bonnet when not connected. The cable from the charger runs through under the rear of the bonnet so it can be closed whilst charging.

My battery failed after 5yrs, denoted by cranking but not firing. Replaced by indy with a Bosch unit.

Signs of battery failure are S/S not cutting in. 14/18 way seats and steering wheel not automatically moving on entry/exit.