Maintain battery over winter without access to power outlet

I will soon have to park my Cayman for the winter and need a battery maintaining solution. I used to charge it with my CTEK CT5 about once, for 12-14 hours, every three weeks during the winter, but I no longer have access to a power outlet since moving. Wanted to check here if anyone had any good recommendations! Currently looking at two alternatives: Buy a CTEK CS Free, a portable battery charger and maintainer. This is supposed to do what I need it to, but the battery capacity of the device seems rather lacking Buy a power station, such as a Goal Zero Yeti 200X, and plug my existing CTEK maintainer to that Appreciate anyone sharing their experiences with this sort of issue

Is pulling the battery an option? You could maintain it at your house, cover the Cayman and leave the frunk on one click with a soft cloth over the latch to prevent accidental full closure.

That really seems the most sensible thing to do, though I've read some posts about leaving a Cayman with no battery over longer periods can mess with the electronics, and lead to various fault and issues once plugged back in.

I know a failing battery will sometimes cause what you describe. I am not sure about battery in/out doing the same, I'm inclined to believe it would be fine. I've had one in and out of my 987 several times during ownership without issue, I would think an even older variant of the car would be fine. Someone here will have removed one and can weigh in and educate us both.

Mine came with the socket for a CTek charger ready mounted, brilliant solution that, literally just plug and play. I just bought one, which I do intend to use, for now though there is still the odd sunny day with dry windy roads and that's all I need to fire up the engine.

My understanding is that in the 987 the big issue with disconnecting the battery is the need to reset the airbag light. This reset requires a Porsche specific OBD tool like a Durametric or Foxwell . At about $150 for the Foxwell , it might be a more affordable solution than portable battery packs. Furthermore, it has plenty of other uses.

How long can you disconnect? Are you saying every battery change requires this?

I've had no problems with disconnecting my battery over an extended period. You get a few error messages and may need to reset your window settings, but all very minor stuff and the warnings (IIRC PSM or something similar) go away after driving a short distance. So I think that option is a good one as long as you don't mind leaving the front trunk unlocked and are sure no one will latch it trying to be a "helpful" neighbor. Removing the battery is a little awkward depending on your body size and arm strength. I found it is easier to lift while standing in the open frunk. You didn't state what type of storage facility you will use. Is it secure (private) or is it in a common (public) parking lot? That will determine if you can safely leave the trunk unlocked with the battery removed. Judging by your login name, you are in Oslo Norway. So you have relatively mild winter weather unless you are in the mountains. (Mild as compared to arctic ) However even if your battery is in good shape it could be a problem leaving it connected for a month. These cars have a bit of parasitic draw. Judging by the two products you mentioned in your original post, you are willing to routinely visit the car and recharge the battery . Keep in mind it would probably take many hours to fully recharge the battery in place. Both of those products are expensive. One option would be to periodically remove the battery and recharge the depleted battery somewhere with electric power using a battery maintainer. over night. Just be sure it isn't in an unvented area where the explosive gases could accumulate. Another option is to buy a second battery and swap them out. Probably cheaper than either of those two products. You don't need to buy an OEM brand battery . Also, I just realized that this question has been discussed many times since I've been a member. So you might want to search to see if you find better solutions.

Before I invested in that technology, I'd just buy another battery keep it charged and rotate them, solves all issues inexpensively. I swapped the last time bringing my battery to Costco and home so it was out a couple hours. No codes, no issues but I do remember one thing that did correct itself the minute you drove a short distance just don't recall what the message was. Everything esle was good to go so a swapping concept would work.

I would do this just to avoid a trip to the dealer to do a "handover procedure" to re-activate heated seats, homelink and headlight washer, etc. When I purchased my car, these items did not work and found out I needed to do a handover procedure. Based on my research, Porsche apparently built in a functionality to minimize battery drain during the transport and "turned off" certain functions, and dealers "re-activated" them (i.e., the handover procedure). In addition, this functionality also detects low battery and starts turning off function-by-function, which again need to be turned on again via the handover procedure which requires PIWIS / PIWIS II (at least of 987). And the previous owner of my car only drove the car like 3000 miles last 7+ years and was sitting in their FL second home, so I suspect the drainage causing this. Having said that, I am not sure at all whether simply removing the battery for a long time / months will not require the handover procedure or not.

If this is always going to be the circumstance, I'd do some homework to see whether a small fresh battery could be applied as a tandem booster to hold these settings; say a motorcycle battery . Then I'd buy two sets of jumpers, two batteries. I'd leave the car battery right in place. I'd fashion a "Y" that could feed two batteries with the post of the "Y" representing the connection to the car battery . Then you have one side of the "Y" feeding the main battery at all times. After whatever time period seems safe, you connect the refreshed small battery to the empty side "Y" and bring the one that was on the other side home to charge, repeat as necessary. This system would remove all consternation about handovers.

Oddly, I've had the opposite experience with my 2009 CS. I've both swapped the battery without an alternate power source and had a completely dead battery with any resulting faults cleared by a short drive (and, IIRC, resetting the auto windows); no airbag light or issues with heated seats. Apparently, YMMV...

The battery in a 987 will only cause an SRS fault if it is LEFT CONNECTED and some part of the SRS system is disconnected. Disconnecting the battery BEFORE working on the SRS system is standard operating procedure. What you will lose with the battery disconnected is the 1-click auto-up/down of the power windows, and the calibration of the steering angle sensor, so you'll briefly get a PSM error message on the dash. Once you travel 100 feet in a straight line the steering angle is reset and the PSM error should disappear. Since when the battery is disconnected none of the modules in the car are seeing any voltage, I can't see how "handover mode" would be triggered. I suspect that mode must be intentionally set - as the car is ready to leave the factory for transport to the selling dealer.