The car was serviced about 3 weeks ago. I brought it home and left it in garage until yesterday. The battery is less than a year old. It is completely drained. I couldn’t even open the door with the fob. I got it jumped started and drove around to charge it back up. Less than 12 hours later it is dead again. Dealership is looking into it. I am guessing some simple stupid mistake they made when it was serviced. Any idea what could be the problem?
Alternator?
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Alternator? Is it a common issue? I never had an alternator problem> Do they drain the battery?
Is it a Subaru? Know problem.
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Could be a bad battery. Happened to my son. Similar to you it was about 12-18 months after he bought a new battery. Took it back to where he bought it and they replaced it for no charge. No issues since (3+ years). Knock on wood.
Could also be a bad alternator. That would mean battery isn’t charging so it drains over time.
My daughter had an issue with her car. Battery would go dead periodically. Replaced it with a bigger battery. Problem was common because manufacturer eventually created a software upgrade that changed how battery was charged. Also hasn’t had the problem since. 2+ years. Again knock on wood.
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Could it be because you have not started the car in several weeks?
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“ A corroded or defective alternator diode will faultily continue charging the circuit even when the car is off. This, in turn, will drain your car battery and cause the car not to start”
Ask me how I know…not my words…this is a Google search. But this happened to me.
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I had a very similar issue with my new car just a couple of weeks ago. Somehow, I guess I left the car running when meeting a neighbor after having just parked the car. I got to talking and left it running. The next morning, it was dead.
I had someone jump it, and it fired up right away. I drove it for about an hour and used the car throughout the day. For some reason, I decided to buy a 750 amp jumper box that day. It was a good thing that I did, because the next morning, the car wouldn’t start. Using the jumper box, I got it started again on a Saturday and drove the car a lot, turning the engine on and off. The next morning it was dead again, so I jumped it and it was fine. Same the next morning (Monday) and took it to the dealer. They replaced the battery (which was basically brand new).
It worked fine for another day, and then it died again! Luckily, my trusty jump starter got it started so I could drive it into the dealer. They decided to keep the car for a week so they could run all sorts of “isolation tests” to see if there was a “parasitic draw” on the battery. There was, and it was coming from the car’s junction box. They replaced that, and the car is working fine.
It took a week, but the dealer was super-careful and got me a rental car while the car was in the shop. I am glad they took the time to do it. Cars are super-sophisticated these days, and all sorts of things are drawing power even if the car is turned off. It’s worth it to do the isolation testing. My car was under warranty, so it didn’t cost me anything except time and aggravation. But it appears the problem is solved.
Oh, and I have already gotten a lifetime’s worth of service from that relatively inexpensive jumper box!
Good luck!
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Had a similar ‘parasitic’ draw problem myself a few years ago. Also, bought a jump starter at that time. Now I keep one in all our cars. Recharge them every Christmas but they hold 98%+ charge all year.
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The car isn’t that old to be corroded, 2019.
Does a parasitic draw happen randomly? I was working fine. No event I can think of to trigger anything other than getting it serviced. Unfortunately for me, a jumper box isn’t powerful enough to start the car. AAA tried the box. The headlights came on but the engine wouldn’t start.
Just a wonderful device! I got mine for $59 on a whim at Harbor Freight after the first jump start (by a third-party). Just having the jumper box saved me huge amounts of time by getting the car started myself rather than waiting for a third-party to jump or tow me. And, yes, it now occupies a special place in my trunk too!
AFAIK, anything can cause it. When I was researching this, I found radios/entertainment centers, door locks etc could cause it. That’s why it’s called an isolation test, as the shop isolated several circuits to identify the problem.
By chance, is your car a PHEV? I’ve had two PHEVs with battery issues, and a jumper box couldn’t start it. The service provided sent a a huge tow truck, and I thought they were going to tow me, but the fellow said he would jump my car off his truck’s super-heavy duty battery (much more powerful than a jumper box). It fired up right away.
HOPEFULLY, you should be able get AAA to do this. If not, I guess it might need to be towed to your repair shop.
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They make 10K amp jump starters that will jump a tractor trailer. What are you driving?
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May be case of correlation not equaling causation in terms of the battery and recent service.
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Does the car make any noise that sounds like it is about to start but then does not or does it stay silent?
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You are very right. I am trying to remind myself that.
@BunsenBurner No. Dead silence. Nothing nada. The car just sits there. This morning I could even open the door with the fob.
We clearly need @skieurope at a time like this. 
I’m assuming you have a real key in the fob to use in case of emergencies? The same thing happened to me, and that was a life-saver. I could open nothing with the fob.
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I mean when you try to jumpstart it. Any noise or dead silence?
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When AAA tried with the box, it made noise briefly as if to start before turning silent. AAA gave up on the box and started from their truck.
I would DEFINITELY call the place where you had it serviced and speak to the manager/shop foreperson. If it is the dealer, they should be able to do the isolation tests and contact the manufacturer’s engineers to troubleshoot the problem.
In my case, it was a new car, so everything was covered in terms of labor, parts, and a rental car (which are not easy to get these days!). They would need to keep your car for several days to isolate the problem.
Given that it was a new car, there was also the California “lemon law” that could have kicked in, so it makes sense as to why the dealer worked on this for several days. I basically would be able to return the car.
The invoice that I received when everything was fixed had DETAILED notes as to all the efforts that the shop foreman went through with the manufacturer.
You will get it fixed, but it might take a bit of time.
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Not a new car, but we had something similar happen to the car my son drives. At first they thought it was the alternator but it turned out to be the serpentine belt. Do not ask me what that is, but they replaced it and the car has been fine since.
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