Battery goes completely dead in 2017 Expy overnight once a while

[17expi]

Battery goes dead overnight for no apparent reason. I doubt if I was leaving anything on.

 

[DieselMonk]

Probably one of the 40 modules in the car won’t go to sleep. The only way to figure this out is time and measure your current consumption. Then you got to figure out which module is causing this.

 

[99WhiteC5Coupe]

Battery goes dead overnight for no apparent reason. I doubt if I was leaving anything on.

You have a bad battery.

 

[Gary Waugh]

You probably have a bad battery or an internal light is not always turning off. Can be very hard to find. How old is your battery?

 

[17expi]

You have a bad battery.

No because it is fine otherwise

 

[17expi]

Probably one of the 40 modules in the car won’t go to sleep. The only way to figure this out is time and measure your current consumption. Then you got to figure out which module is causing this.

I think I will just get one of those jump starters. It only happens about once a month.

 

[17expi]

You probably have a bad battery or an internal light is not always turning off. Can be very hard to find. How old is your battery?

The battery is fine and acts normally 99% of the time.

 

[17expi]

You probably have a bad battery or an internal light is not always turning off. Can be very hard to find. How old is your battery?

.......not the battery

 

[Gary Waugh]

I have had the occasional bad battery where one of the cells or connections to the cells goes open circuit occasionally, so the battery appears to be dead, but once I restart the car, the battery then works fine. I suspect you might have something similar. Next time it happens, try to measure the battery voltage before starting the car. If the battery has a mechanical fault you will see very low voltage, if the battery is flat, you will usually see something above 9 volts. If it’s flat then you have something taking current when the car is turned off (interior light, etc), but if it’s showing a very low voltage then it’s probably a failed battery. Just something to check if you can next time it fails to start.

 

[17expi]

I have had the occasional bad battery where one of the cells or connections to the cells goes open circuit occasionally, so the battery appears to be dead, but once I restart the car, the battery then works fine. I suspect you might have something similar. Next time it happens, try to measure the battery voltage before starting the car. If the battery has a mechanical fault you will see very low voltage, if the battery is flat, you will usually see something above 9 volts. If it’s flat then you have something taking current when the car is turned off (interior light, etc), but if it’s showing a very low voltage then it’s probably a failed battery. Just something to check if you can next time it fails to start.

Thanks, I will check. I always check for anything left on so it's really strange. Totally dead but will start after a half hour of charging with 6 amps.

 

[chuck s]

Part of the design is to leave the "ports" hot all the time. Innocent items like a "microwave detector" or any other device will drain the battery. I don't drive my '17 daily and have resorted to a 8"x12" solar charger on the dash to keep the battery charged even though nothing is left plugged in. In my '07 I installed a "Priority Start" (I think that's the brand name) battery disconnect or she'd not survive a week parked at the airport -- nothing better than getting back at 10:00 PM and it not starting!

-- Chuck

 

[ZigZagFred]

The electrical system in modern vehicles is well-engineered and very elaborate. The weakest link in that complicated system is the battery. If one is having ANY issues with their electrical system, the first visit should be to a reputable place that specializes in batteries. I recommend Battery Joe, or Batteries and Bulbs. They can evaluate your battery and the charging system for free.

 

[BlackBetty]

Had this happen to a coworkers F150. Troubleshot it down to the interior dome light not shutting due to a bad rear driver door switch. The vehicle saw the door as never having been shut; though it was. Pretty easy fix once you narrow it down to that component. If that’s your problem. Could been many things…

 

[Neights Templar]

Battery goes dead overnight for no apparent reason. I doubt if I was leaving anything on.

I have a 17 also that was going dead on me. Turned out my rear wiper was not getting to the shut off position, thus causing the battery to drain over night. Open the back window and put a little WD40 on the moving parts of the wiper on the window and the motor area. I was lucky that the motor did not burn out. This fixed my problem though.

 

[Utah Driver]

I've also heard of the glove box light staying on and draining the battery.

 

[Gregg Eshelman]

I had that on my 07. It would go dead once in a while. Then it got worse. Finally it acted like a dead short when I'd put a charger on it. Turned out it was a short in the alternator. Fortunately this generation has pretty much the easiest to remove alternator there's ever been.

Take it off and take it to a NAPA, O'Reilleys etc with a good alternator tester.

 

[ManUpOrShutUp]

This can be tough to track down. I had it happen last year and it turned out to be my front passenger door switch. At random points during the day/night, it would trigger as if the door was opening. Lights would come on, then go off. I have no idea how often this was happening, but it was enough to occasionally kill my battery. I didn't figure it out until I happened to be walking the dog in the yard one night when it happened. Then I turned off the automatic lights thinking I could procrastinate over replacing it for a bit. That plan went south when I was out for a walk at the local trail and heard my alarm going off when I was still a half mile away. Apparently the switch triggered while the truck was locked, which in turn triggered the alarm. $6 later, all fixed. Best of luck.

 

[17expi]

It looks like it could be a lot of things but thanks for the ideas, I think I will just get one of those jump starters since it rarely is a problem. The Gooloo 4000 from Walmart looks to be the best bang for the buck.

 

[Gary Waugh]

I always prefer to find the cause and fix it, things only get worse, never better but getting a small jump starter box sounds reasonable as long as it doesn’t start happening more often. The jump starter boxes are always useful things to have.

 

[17expi]

I always prefer to find the cause and fix it, things only get worse, never better but getting a small jump starter box sounds reasonable as long as it doesn’t start happening more often. The jump starter boxes are always useful things to have.

I was a mechanic and normally fix things and might still after I eventually get a new battery. This one is 5 years old but very strong. The problem only happens about every month.