There was a post here a few months back about someone with a Porsche Boxster I think that had this same problem. She’d park the car for 4 or 5 days and the battery would be dead. I don’t recall there being a solution, it is just the way the car was designed to work (or not work, depending on your point of view.) So I expect there is truth to what the dealership is saying, with all the electronic gadgets that remained power up in modern cars, parking the car for 4 or 5 days may well drain the battery enough so it won’t start the car. This will be more likely to happen in very cold weather. You will probably discover in the summer it isn’t as much of a problem.
There’s a few things I’d probably do though.
When a battery gets discharged, its freezing point rises. So it is possible when this happens, it could freeze in very cold weather and ruin the battery too. So have the battery load tested after this happens in the winter.
Have the “off” battery current measured. There may be a switch sticking or something sucking up more current than it should when the car is turned off.
If there has been any add’l electronics added to this car post-manufacture, especially alarm systems and audio equipment, suspect that first as the cause.
Some dealerships install anti-theft electronic equipment on the cars while they are unsold on the lot. Make sure that has all been removed.
I’ve heard here of complaints that a monitoring device has been placed on their car which enables the seller to turn off the car if the monthly payment isn’t made on time. Or to tell the seller where the car is located. Ask the dealership if something like that has been placed on your car.
If battery acid spills on the battery case for some reason, that can create a current path that will self-discharge the battery even if the battery itself is completely disconnected. So make sure the battery case is cleaned of contaminants regularly.
Ask the dealership if there is some rarely used function that can be disconnected during the winter.
If all this doesn’t solve the problem, you may need to buy a used car from the golden age of cars, mid-90s, to drive to the airport in the winter.
@Keith,dont think autozone around here would ever replace the overpriced battery for you on the the other hand Advance Auto would,maybe some stores in other places would? The type of memory in a auto computer is PROM or something like it ,isnt it? so really theres no reason to worry about your car not running if you replace the battery,on the other hand accessorys like radios will lose thier presets and that line that dealer or whoever was handing out was total Bravo Sierra,if a car battery wouldnt hold its charge any longer then that,maybe we need a recoil start lawnmower engine to start the primemover(you ought of heard some of the BS ,mechanics and shysters used to hand me at a town I no longer frequent)-Kevin
If it were true that there was a car that drained the battery in 5 days that mens even if it were driven every day the battery would get drained up to 20% each day.
Any lead-acid starting battery that was drained to 80% full each day would soon fail from sulfation and plate erosion because these batteries (unlike “deep cycle” batteries) are designed to deliver no more than 1-2% of their capacity each time the car is started, then get filled back up by the alternator.
@kmccune: You would think that there would be no problem and that any car would be designed to recover gracefully from a total power loss, but in practice, this seems to not be the case. I have never experienced anything worse than having to reset station presets and clocks, and having a car run a little weird until the computer relearns the engine, but I have heard horror stories from others.
I know there was a certain pickup (GM?) that used an Allison transmission that needed to be reprogrammed by the dealer or it would not move. I have heard other stories about more minor events like accessories that no longer work right, keyless entry that won’t work, radios that won’t respond, etc. I think most of these can be fixed by either disconnecting power again to reset the devices, or following the owner’s manual on how to reprogram or recalibrate these. Apparently some of these can “wake up crazy”, so to speak.
But I would say that it’s extremely poor design and foresight for any engineer to let something consumer-grade be released to the public that requires anything more than very simple steps to recover from a dead battery, which will surely happen to any vehicle several times in a normal lifespan.
@Oblivion and curcuitsmith,thanks and if people would learn the fundamentals of battery care it would help,not magic,just electrochemistry and electronics-Kevin
If it’s true that there are vehicles that don’t recover on their own from a dead battery, I’d love a list so they could be put on my permanent “DON’T BUY” list.
My '05 Pacifica has every factory option, including navigation, Bluetooth, remote amps, memory seats, etc. Granted it’s 7 model years old, but these gizmos power down when the ignition switch is turned off, and it can sit for weeks in cold weather with no starting problems (except for the recent defective battery I bought from one of the big box auto parts stores).
Do the math, a car battery holds about 80 AHr of charge over a 20 Hrs (that is 4 amps for 20 hours). Over 5days, 120 Hrs, a current draw of 0.66 amps is required to discharge the battery.
Unless you have installed extra electronic gadgets that don’t turn off, you have a current leak. An 8 watt light consumes 0.66 amps so a glovebox light could do it.
I switched all my interior car lights (dome, map and glovebox) to LED bulbs, so even when the kids leave the car doors open I can start the car after a full weekend.
you need to re charge youre battery, your car’s charging system will maintain the battery not recharge it from seating for an extended period of time. it may be worth buying a jump box and keep in the car when you travel or use Rapid Roover and put a battery tender on the car saave the high parking rates
