# Mystery Battery Discharge **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** envoy, gmc\ **Created:** [November 20, 2017, 8:58pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545 "2017-11-20T20:58:58Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![AgentEd](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@AgentEd](https://community.cartalk.com/u/AgentEd)\ **Post date:** [November 20, 2017, 8:58pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/1 "2017-11-20T20:58:58Z")
My daughter recently started working at the local Taco Bell 🌮. Almost everyday she finishes her shift at around 3 PM. Many times the battery is dead or almost dead and I have to jump start the car. On her days off or any time that the car sits at home, or any other location for that matter, the battery is fine. I have had the charging system checked and everything checks out. I have cleaned and tightened the terminals. The battery is 3 years old and seems to do well here in Ohio. Do you think that the car is opposed to tacos or could it be something else? ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [November 20, 2017, 9:06pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/2 "2017-11-20T21:06:29Z")
When does she start her shift? Is it dark out? Is she leaving the lights on? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [November 20, 2017, 9:09pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/3 "2017-11-20T21:09:21Z")
How far is the vehicle from the key fob when your daughter is at work? [http://www.autoserviceprofessional.com/article/94711/Today-s-key-fobs-smart-keys-Technological-advances-provide-convenience-and-cause-problems?Page=2](http://www.autoserviceprofessional.com/article/94711/Today-s-key-fobs-smart-keys-Technological-advances-provide-convenience-and-cause-problems?Page=2) Tester ---
**Author:** ![TwinTurbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@TwinTurbo](https://community.cartalk.com/u/TwinTurbo)\ **Post date:** [November 20, 2017, 9:19pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/4 "2017-11-20T21:19:49Z")
The last year for Trailblazer/Envoy was 2009. AFAIK, they never had these fancy FOBs, just the old plain jane version with unlock, lights and panic buttons. But, you may be on to something if a key is pressed and the vehicle continues to respond to it. My initial thought was people using it during breaks, playing radio, fans running etc… ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [November 20, 2017, 9:23pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/5 "2017-11-20T21:23:06Z")
Then why are they available? [http://www.bing.com/search?q=2009%20envoy%20key%20fob&pc=cosp&ptag=C1A005A2B4283&form=CONBDF&conlogo=CT3210127](http://www.bing.com/search?q=2009%20envoy%20key%20fob&pc=cosp&ptag=C1A005A2B4283&form=CONBDF&conlogo=CT3210127) Tester ---
**Author:** ![AgentEd](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@AgentEd](https://community.cartalk.com/u/AgentEd)\ **Post date:** [November 20, 2017, 9:25pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/6 "2017-11-20T21:25:00Z")
She starts between 6:30 AM and 8 AM. The lights are automatic. So, she never turns them off or on. I have them set on a 10 second delay when the car is turned off. I checked and they turn off correctly. The fob is about 110 feet away and won’t even work if you are standing more than 10 feet from the car. I will check out the article though. ---
**Author:** ![AgentEd](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@AgentEd](https://community.cartalk.com/u/AgentEd)\ **Post date:** [November 20, 2017, 9:34pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/7 "2017-11-20T21:34:36Z")
She was listening to the radio for about 10 minutes when she first started, but has stopped since this all came up. The spot where she parks has a steep drop off in front of it. Maybe the charge is running down the hill 🙂 ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [November 20, 2017, 9:41pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/8 "2017-11-20T21:41:47Z")
Is it possible that her key comes out of the ignition switch in the ACC position? ---
**Author:** ![AgentEd](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@AgentEd](https://community.cartalk.com/u/AgentEd)\ **Post date:** [November 20, 2017, 11:47pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/9 "2017-11-20T23:47:31Z")
No.Doesn’t seem to to be able to pull the keys out with the switch out of position. ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [November 21, 2017, 3:25am UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/10 "2017-11-21T03:25:58Z")
> [@AgentEd](#): > > The battery is 3 years old and seems to do well Have the battery tested . . . it might be in marginal shape, maybe it can’t hold a charge How cold does it get at night, where your daughter works? A marginal battery might fall flat on its face If that’s not the problem, perform a parasitic draw test ---
**Author:** ![Marnet](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/marnet/32/41_2.png) [@Marnet](https://community.cartalk.com/u/Marnet)\ **Post date:** [November 21, 2017, 3:32am UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/11 "2017-11-21T03:32:50Z")
Please do not discount the possibility someone is somehow messing with your daughter’s car during her work shift. The fact this happens only at her job location is a red flag. Many of us women have had to deal with vehicle sabotage by creeps at some point – flattened tires, ripped headliner, gouged paint, etc. How someone could drain her car battery, I’ve no clue but please consider the possibility. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [November 21, 2017, 3:48am UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/12 "2017-11-21T03:48:21Z")
The post reminds when Tommy would ask: Doesn’t anybody screen these calls?? … lol … I have no idea why the GMC won’t crank the engine after the Taco Bell shift, but I can offer up a few wild guesses … hmmm … maybe I’ll make me a taco first … 😉 - the vehicle is parked on a different angle (slope) than usual, and that’s causing the stuff in the engine compartment to shift its orientation a little and maybe pinching a wire or affecting the battery (suggest to check the battery fluid level). - there’s more wind or big trucks going down the road in that area, and the effect of all that is bouncing the doors enough to cause a door switch to turn on briefly. That makes the computer think somebody’s getting into the car so it powers up the engine computer, and that powers up the other computers, all of them getting ready for the driver to start the engine and drive away. - there’s radio frequency interference that’s turning something on. especially should be considered if there’s an alarm system installed in the vehicle, it has remote start, or a remote door opening function. - something is different about what’s being left on the seats, or not left on the seats while parked at Taco Bell. that can affect airbag or other safety circuitry in some cars. The standard way to figure this kind of problem out is to install a current meter in series w/ the battery negative circuit when the vehicle is parked and everything turned off, then monitor the current draw. should be less than 50-75 mA or so. Bet of luck. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [November 21, 2017, 5:07am UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/13 "2017-11-21T05:07:15Z")
Is she applying her make-up, brushing her hair just before going in to work and leaving the dome light or vanity mirror light on? Not closing the car door all the way ? Letting friends go sit in the car during their breaks or lunch? ---
**Author:** ![AgentEd](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@AgentEd](https://community.cartalk.com/u/AgentEd)\ **Post date:** [November 21, 2017, 1:32pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/14 "2017-11-21T13:32:24Z")
To answer some of the questions. 1. The problem started in the warm weather and has continued to this colder time. (and it has no problem when it sits overnight or on her days off) 2. She doesn’t have friends at her work that she would let sit in the car and she doesn’t wear much makeup. (Natural Beauty 🙂 ) 3. The parking lot is level and the store is in the shopping district and sits about 15 feet above street level (hill country), so no big trucks come barrelling by. 4. Yes, I did think of Tommy on this one. I am wondering if someone is experimenting with EMP’s in the area (It is a college town) 5. I have pushed the dome light button so that they don’t come on at all. Also, they shut off after a few minute delay. ( I have even left the door opened at home, accidentally, with no ill effect) 6. I haven’t checked the seat situation, but it might be worth a try 7. There is no remote door open or car start, just a simple lock on the fob Another hint: She always parks in about the same spot (I know know because the spot next to her is usually open when I come to jump start her) Last week, the person next to her was also getting a jump start. ---
**Author:** ![TwinTurbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@TwinTurbo](https://community.cartalk.com/u/TwinTurbo)\ **Post date:** [November 21, 2017, 3:39pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/15 "2017-11-21T15:39:26Z")
Those are simple FOBs not the smart one you originally referenced. All they do is transmit an RF signal to actuate an input on the vehicle side. I as much said that in the prior post. ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [November 21, 2017, 3:53pm UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/16 "2017-11-21T15:53:46Z")
> [@George\_San\_Jose1](#): > > there’s more wind or big trucks going down the road in that area, and the effect of all that is bouncing the doors enough to cause a door switch to turn on briefly. That makes the computer think somebody’s getting into the car so it powers up the engine computer, and that powers up the other computers, all of them getting ready for the driver to start the engine and drive away. Not sure if the word ’ Ridiculous ’ even covers that statement. ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [November 22, 2017, 2:46am UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/17 "2017-11-22T02:46:15Z")
> [@AgentEd](#): > > it has no problem when it sits overnight or on her days off) That might be the key right there What is happening at work, or at that location, that does not happen when she has the day off? Perhaps some guy at her work is doing something to drain her battery, and he hopes/plans to be her “saviour” . . . some guys engineer some pretty bizarre situations, for the purposes of meeting women ---
**Author:** ![thegreendrag0n](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/thegreendrag0n/32/9265_2.png) [@thegreendrag0n](https://community.cartalk.com/u/thegreendrag0n)\ **Post date:** [November 22, 2017, 3:50am UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/18 "2017-11-22T03:50:45Z")
in such a case, she might try recording what’s going on with a dashcam I bought a dashcam on amazon for $25 plus $10 memory card and found it was not only a decent 1080p video, but embedded rechargeable battery, vibration detector, motion detector, etc…, which might be handy in this situation ---
**Author:** ![Marnet](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/marnet/32/41_2.png) [@Marnet](https://community.cartalk.com/u/Marnet)\ **Post date:** [November 23, 2017, 1:57am UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/19 "2017-11-23T01:57:52Z")
db4690 that’s a possibility. More likely, some creep is on a prolonged vengeful binge because the young lady hasn’t responded to him the way he wants. Or is one determined creep seeking opportunity to actually harm her by making her vulnerable. I know my comments may seem paranoid but at least half the women I know along with myself have been victims of such malicious vehicle sabatoge or damage at some point over the years, most often when young and having pissed off some twisted young creep. ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [November 25, 2017, 1:19am UTC](https://community.cartalk.com/t/mystery-battery-discharge/109545/20 "2017-11-25T01:19:08Z")
I am trying to think how one would drain a battery, or why in one particular area of the lot this would happen without intervention. I cannot conclude anything but the idea it is user error, not a nefarious plot. [Next page](https://community.cartalk.com/t/mystery-battery-discharge/109545.md?page=2)