Battery + 1 Month Storage

I am leaving Montreal for a month stay in Barbados - I teach a field course there. My CS is parked in an indoor parking garage and covered. My question is whether I should worry about the battery discharging over the month - the temp is around 20-25C. Since other folks have access to the garage, I don't want to leave the car unlocked. Seems most other threads are concerned with long term storage (over the winter). What about short term - one month? I do have a CTEK battery maintainer - though the AC outlet is a bit far (will have to use an extension cord) and awkwardly located relative to my parking spot. Nevertheless it could be connected if absolutely recommended/needed.

You don't need to leave the car unlocked. Leave the battery tender pluged into an extension cord on the drivers side floor, and run the extension cord (flat, not round type of cord) across the door sill and out of the car. Close the door and lock it. You will need the tender for a one month absence.

thanks j_copeland. Is plugging the CTEK into the aux. plug in the car preferred/safer over connecting it directly on the battery? Given the length of the extension cord I was going with a AWG16 guage extension cord (unfortunately round) - though I guess its OK to have the CTEK cord run out of the door sill (?).

You can easily run the CTEK cord or an extension cord between the door glass and "A" post. Most battery tenders caution against extension cords "unless absolutely needed". Make sure that the extension cord is in good condition, has the same number of plugs as the CTEK and sufficient Amps to power the tender.

There are lots of diffrent battery tenders--and you don't need to spend more than US$25 for one. You only need one with an output of 1 to 2 amps/ 12 volts. Current drop over a length of extension cord is absolutely not a problem. Also not a problem to plug it into your cigarette lighter. I would spend a few $ on a flat extension cord, and not use round cord from batt tender, so as not to deform the rubber door seal.

You may already know this, but after a week the remote system will shutdown - you will have to use the key and unlock the driver door manually. One thing that I have not seen as yet, someone post actual numbers on the current drawn by the car while the car is switched off, with the door unlocked, door locked, and after one week once the remote has shutdown. If we had some numbers it would be possible to see how long the battery could last - the stock battery is 80 AHr, so as an example, if the car was drawing 200mA, it would be using 0.2*24=4.8AHr per day. As I recall one should not go below 50% of the battery capacity, which would give us about 40AHr assuming a battery in good condition fully charged.

Simple, if it dies after 1 month storage take it back to the shop.

I connected my CTEK (model MULTI US 3300) and ran a flat cord thru the door sill. A tight fit probably to it being a 18 guage cord. Its been connected for about 24 hours and has yet to indicate going into "trickle" mode (indicator symbol for trickle charge is a battery that is completely filled). Instead it indicates being in the "charge" mode (indicator symbol is a battery half filled). Is this normal? I drove my CS several 100 kms prior to connecting everything - why would the battery need to be chraged?

It will take about 24 hours to get to fully charged. (the old battery tender thread had some examples) Did you make sure you selected the "car" option? If you run the car up between the "a" piller and the door there is very large gap you can run in through. I can take photos if needed.

Thanks Santa Fe. Yes please do post a photo since I am not sure of the exact position. Right now I have a cord thru the door sill - but its very tight.

Flying Fish, here you go. A picture is better than a thousand words they say. I've put two sizes in for comparison. They are below the rubber seal so there is no crimping of the seal. Also I don't think most of us understand how are batteries are not in a fully charged state if only driven on a limited basis. All of those many electronics must put a real drain on the battery.

If you get the battery tender from our sponsor Ralph Boothe at www.BootheDesign.com I know you can run the wires between the hood and the glass near the wipers just fine as that's what I've done on a couple of occassions, you can close the hood with no problems. If you don't have one of these give Ralph a call, they are great!

The directions on the Porsche charger (ctek), says it can take up to 27 hours to just get to 80% than it will take even more time to get to the pulse mode. Thats normal. Also, just run charger cord out the door sill, there is no need to have the bulky extension cord in the car. It works fine.

Chow, I think FF's car is going to be parked in a public spot which means he needed to leave the charger in the car to protect it and it is also too far away from a plug thus the need for an extension cord. Ken he mentions he already has a charger.

That's correct SF. Though I don't think the other users of the garage would be likely to take anything, I would rather play it safe and not have a surprise upon my return. Thanks SF for the photo - perfectly clear now! The CTEK unit finally changed to maintenance mode (green light).

Got it. But you need to hope someone doesn't unplug your extension cord. If the charger is plugged into an outlet in the car and unplugged, it will draw backwards and drain the battery. You can easily see this. Just plug in the charger in the outlet in the car and do not plug the charger in. The little light on the charger will glow, albeit now as brightly as when plugged into AC

my CS sat in my garage without being started for 8 or 9 weeks this winter at below zero temps and no battery tender. It fired right up no problem. Have fun in barbados, drink a little Mount Gay Rum for us- as they would say "now dis is dah Rhum!"

aaronr was your car locked? I think that a locked Cayman draws more amps from the battery than an unlocked one (at least until the automatic shut-down of some functions) but I'm not sure how much. Battery condition before leaving it stored is another interesting factor. If it is close to being fully charged then it has a better chance of surviving I'd guess. Does anyone know what the Porsche procedure is for charging the battery prior to delivery? Is it possible that the batteries are not fully charged when delivered and if not driven extensively stay in a state of low charge?

SF - you may have something here. I think dealer procedures including shipping from Europe, storage, etc may play a part in the problems people seem to be having with the battery. I still have not seen any real numbers on power drain but I am sure a locked car would be greater with the security system on, door latches energized, remote key operations ( for the first week of the car being locked ). I recently visited a friend car mechanic and he was working on his VW GTI, and was using a small dry cell battery while he disconnected his main battery in order not to loose any settings - this also helps with current surges when one re-connects the battery.

My car was brand new, so battery was new. Car was unlocked with the windows down just in case.

Well I am now in Barbados getting certified (for diving that is) - at Bellairs Research Institute in Holetown (sorta like Pittsburgh, eh) to be exact. In the end I left the cord going thru the door sill - a bit more optimal when using a car cover. When winter comes (gulp!) I'll pass the plug thru the A pillar as suggested by SF. Ya I hope no one unplugs my car - we'll see! I placed a little sign indicating that it should not be unplugged. Actually I really hope that I remember to remove the cord after my return - would make for some interesting damage! Oh that's going to keep me up tonight - well that and the rhum! :beer: