Woke up yesterday to find that the battery in my 2016 discharged completely overnight. No warning and there weren’t any prior problems.
Been using the car every day so it wasn’t the normal drain found if the car isn’t used.
I used my key to get into the trunk and jump started the car and then drove it for a half hour to charge. No problem this morning and everything seems fine otherwise.

any ideas what may have cause this???
( thanks in advance)

 

First idea is your battery is almost dead. Buy a new battery.

Elmer

 

thanks, but not “almost” dead. It’s fine today and is not going dead. It completely discharged almost as if it were some sort electrical drain. Even an almost dead battery has enough power to allow the door locks to open. Something drained the battery completely
Maybe a computer problem???

 

I second Elmer's hypothesis. The battery is on its way out and is beginning to act squirrelly.

I suggest,at a minimum, as your first action to get the battery tested and go from there.

 

"...fine today" doesn't count, unless you want a repeat or worse. Replace the battery. If you do an "Advanced Search" here you'll see. Just sayin... All the best.

 

No mention of who old your battery is?
If it's the original, no need for wondering or asking what happened, simply replace it. Battery life is typically 4>6 years in these cars.

 

Draining the battery to 0 does immense damage to the battery. The fact that it recovered is miraculous. The problem is, it will do it again. When? That's your guess. Mine did a slow start one time and the battery was replaced immediately and no worries from me.


This car is an electronic smorgasboard of possibilities to go nuts. Usually 99/100 the battery is the culprit when the .



Elmer

 

I agree - at a minimum get the battery tested but most likely just replace it and be sure it is good.

 

So you asked for ideas on what caused your 5 plus year old battery to fail, you were advised to get a new battery as it is old and will fail on you again - you dont seem to like that idea for some reason?

 

Did you forget the accessories on all night?

 

If it's the OEM battery, I'd get an electrical system check and replace it... My experience has been that anything beyond four years is living on borrowed time.

 

Is there any white powder on the terminals? If not, take it someplace and test it under load. Good luck!

 

thanks everyone! I will have the battery tested and start there.

 

There's also another test they can do an overnight discharge test. It's the proper test to see if the battery drains. I might eventually buy a machine to do my own tests. I have a load tester that cost me 40$ but not appropriate for drains.

 

Never said I didn’t like that idea and a battery replacement may be in order. However, the problem seems to be an electrical drain rather than a battery. I’m just hoping to get the problem solved correctly the first time. I have no problem replacing the battery which is probably the simplest and least costly fix. I’m actually hoping that is the problem, but the symptoms don’t point in that direction.


QUOTE=hummiscorvettetaken;1603393917]So you asked for ideas on what caused your 5 plus year old battery to fail, you were advised to get a new battery as it is old and will fail on you again - you dont seem to like that idea for some reason?[/QUOTE]

 

I have doubts that a completely dead battery resurrected itself.
If there was no electrical power, I would check battery cable connections.

 

If you have a good multimeter, you can do a check for parasitic draw on your battery. Basically, disconnect the negative lead, set the multimeter and leads to read DC current (amperage highest range, if not autoranging), attach one lead to the battery post, the other to the clamp, and see if you're car is drawing current with everything off and closed. I don't know our cars draw normally, but I'd guess something less than 100mA (milliamperes, or milliamps and I'd guess probably close to 50-60). If you're drawing more than that with everything off you start pulling fuses one at a time to isolate the circuit causing the draw, and troubleshoot from there to find the faulty component.

Ton of YouTube videos on how to do it, and probably a thread or three in the tech forum here. Really not difficult to do, but there could be some specific info on doing it for a C7. I'd poke around in the tech forum and ask if you can't find anything. Key thing when doing the check is to get the meter set correctly and put the leads in the current measurement sockets. Forget the leads in the voltage sockets and you'll burn your leads up in a hurry, and possibly your meter. And, keep your posts and clamps wire brushed, spotless, and sealed with battery post sealant. Maintaining a clean, tight post/clamp contact is critical, regardless of your batteries age.

Mike

 

Also if your terminal posts lose contact it may seem like a dead battery until it wiggles and make contact again. It happens on occasion in the work van, all of a sudden no start until I remember to re tighten the posts.

 

The same thing happened to my Corvette, also 2016 z 06 with a one year-old battery. It’s not a fault of the battery. The battery went 100% dead in less than 24 hours. jumpstarting the car fixed the problem.. There must’ve been a considerable drain on the battery… Almost a dead short.

 

Did yours happen the same year as the OP thread ? Or just recently.