Key locked in car for weeks...will battery be OK?

[Mac]

I recently bought a used 2017 Ford Fusion Hybrid (24,000 miles). I am going on a trip and want to leave the car at a friend's house near the airport for 3 weeks. I want to lock the key in the car and open it with the keyless entry code when I return. Will my battery still work to open the door 3 weeks later? If not, what are my options? Thank you.

[Cobra348]

Do not let it sit for over 28-30 days without a startup.  It takes that long for the car battery to get so low it will not start the car.  My brother made that mistake ... boy was he embarrassed.  I suggest starting within 3 weeks to be safe ... and make sure the HVB is as charged as can be.

 

Have a contingency plan ready should you be delayed in returning.

Edited January 19, 2020 by Cobra348

[murphy]

Connect a battery maintainer to the 12 volt battery jumper terminals under the hood.

 

[mwr]

2 hours ago, murphy said:

Connect a battery maintainer to the 12 volt battery jumper terminals under the hood.

 

Could you instead just remove the 12v battery?

[murphy]

2 hours ago, mwr said:

Could you instead just remove the 12v battery?

Not if you don't have the metal key, which is hidden inside of the fob, with you.  The battery is in the trunk.  If the trunk is closed and the battery is disconnected the only way into the car is as follows:

Pop cap off of drivers door handle that covers the key slot. 

Insert key and unlock driver's door.

 

There are two paths from here.

1  Pop the hood and connect a jumper battery to the terminals under the hood.  This will allow the trunk to be opened with the fob or with the keypad on the drivers B pillar.

 

or

 

2. Crawl into the back seat and open the passenger rear door.  Fold the seat back down.  Pull on the rope that you previously connected to the trunk emergency release.

If you didn't install the rope, fold the driver side seat back down and figure out a way to get hold of the emergency release handle to pull it.

 

I have the rope in place in my car plus a jumper battery in the trunk.

 

 

To the OP:  Don't you trust your friend to safeguard your keyfob while you are away?

 

The keyfob being in the car will not run down the 12 volt battery unless someone keeps touching an outside door handle to make the car query the keyfob.

As long as the keyfob is not in the slot where it can read the chip directly the car will not know the keyfob is in the car.

 

[mwr]

3 hours ago, murphy said:

The keyfob being in the car will not run down the 12 volt battery unless someone keeps touching an outside door handle to make the car query the keyfob.

As long as the keyfob is not in the slot where it can read the chip directly the car will not know the keyfob is in the car.

 

My 2015 FFH doesn't have a key fob, but instead a flip-out key. Does that mean my 12v battery wouldn't run down if the car is sitting unused for a long time?

[murphy]

22 minutes ago, mwr said:

My 2015 FFH doesn't have a key fob, but instead a flip-out key. Does that mean my 12v battery wouldn't run down if the car is sitting unused for a long time?

Define a long time.  The microprocessors in the car, a lot of them, are running all of the time.  If the battery drops to a critical level the car goes into deep sleep.  External contact, if your car has that, is terminated.  The only way to wake it up is by physical access to the car.  My memory is telling me that the Owner's manual will tell you how long it takes before it is a problem.  If you have a real key does it also open the trunk or is it only for the driver's door?  The car is a rolling computer and the only way to completely shut it down is to disconnect the 12 volt battery.

 

Fact that many people don't know.  The accelerator pedal is not connected to the engine.  It is connected to the computer.  It is two variable resistors with a total of 6 wires going to the computer.  The computer has total control of the engine.  It is truly "fly by wire".

[mwr]

1 hour ago, murphy said:

If you have a real key does it also open the trunk or is it only for the driver's door?  The car is a rolling computer and the only way to completely shut it down is to disconnect the 12 volt battery.

Ha ha, the key doesn't open either the trunk or the driver's door. So my option for storing the car would be disconnecting the 12v battery.

[mwr]

On my 2015 FFH with flip-out key, I don't see a way to open the locked driver's door with the key, nor do i see anything in the owner's manual about doing that. Above: " Pop cap off of drivers door handle that covers the key slot." I don't see a "cap" to pop off. I sure hope I'm wrong.

[murphy]

9 hours ago, mwr said:

On my 2015 FFH with flip-out key, I don't see a way to open the locked driver's door with the key, nor do i see anything in the owner's manual about doing that. Above: " Pop cap off of drivers door handle that covers the key slot." I don't see a "cap" to pop off. I sure hope I'm wrong.

See pages 46 and 47.

 

http://www.fordservicecontent.com/Ford_Content/Catalog/owner_information/2015-Fusion-Hybrid-Energi-Owners-Manual-version-1_om_EN-US_05_2014.pdf

 

 

[mwr]

2 hours ago, murphy said:

See pages 46 and 47.

 

http://www.fordservicecontent.com/Ford_Content/Catalog/owner_information/2015-Fusion-Hybrid-Energi-Owners-Manual-version-1_om_EN-US_05_2014.pdf

 

 

Thanks! It's on p 47-48 in my PDF manual. I had been looking under "Locks" instead of "Keys and Remote controls".

 

http://www.fordservicecontent.com/Ford_Content/Catalog/owner_information/2015-Fusion-Hybrid-Energi-Owners-Manual-version-2_om_EN-US_11_2014.pdf

Edited January 20, 2020 by mwr
Added link to owner's manual.

[mwr]

Well, I tried and can't get this to work. I inserted the key in the slot, pressed upward, but couldn't move the "cap" rearward on the door handle. Has anyone successfully done this?

[murphy]

54 minutes ago, mwr said:

Well, I tried and can't get this to work. I inserted the key in the slot, pressed upward, but couldn't move the "cap" rearward on the door handle. Has anyone successfully done this?

Yes.

It only moves a small amount to the right and then pull toward you.  You may find a small blade screwdriver easier to push up with than the key.  They specified using the key since most people wouldn't have a screwdriver with them.

 

[mwr]

13 minutes ago, murphy said:

Yes.

It only moves a small amount to the right and then pull toward you.  You may find a small blade screwdriver easier to push up with than the key.  They specified using the key since most people wouldn't have a screwdriver with them.

 

Thanks! I'll try that soon.

[Mac]

On 1/19/2020 at 3:12 AM, murphy said:

Connect a battery maintainer to the 12 volt battery jumper terminals under the hood.

 

Thank you for the suggestion (and for all who replied). I have no access to an outlet to plug in a battery maintainer where my car will be parked. However, while I was researching battery maintainers I found a recommendation for a solar maintainer ==> https://www.amazon.com/SOLPERK-Panel，Solar-Charger，Solar-Maintainer，Suitable-Powersports/dp/B07QC13C2R/ref=asc_df_B07QC13C2R/?tag=&linkCode=df0&hvadid=343389557500&hvpos=1o1&hvnetw=g&hvrand=10273484778022173919&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031285&hvtargid=pla-738510810936&ref=&adgrpid=69024256077&th=1

 

Do you think this would work?

Thank you!

[murphy]

1.8 watts is very low to keep a battery charged.  That is only 0.15 amps.  I have an 18 watt solar charger on the roof of my shed to keep the battery in my lawn tractor charged.  I see a power port plug in the picture.  You can't charge the battery through one of the cars power ports.  They are not connected directly to the battery and get turned off after 70 minutes.  Whatever you use must be connected to the battery terminals under the hood.

 

[Mac]

33 minutes ago, murphy said:

1.8 watts is very low to keep a battery charged.  That is only 0.15 amps.  I have an 18 watt solar charger on the roof of my shed to keep the battery in my lawn tractor charged.  I see a power port plug in the picture.  You can't charge the battery through one of the cars power ports.  They are not connected directly to the battery and get turned off after 70 minutes.  Whatever you use must be connected to the battery terminals under the hood.

 

Bummer...I was hoping that would work. The picture shows red and black clamps, but it sounds like 1.8 watts is not enough. Thank you for your assistance.

[mwr]

4 hours ago, mwr said:

Thanks! I'll try that soon.

I tried that with both the key and a small screwdriver, but couldn't budge the cap on the door handle. I even propped open the forward part of the handle so I could get a better grip and rearward pressure on the cap. Any more suggestions?

[murphy]

Are you inserting the key (screwdriver) in the hole in the bottom of the cap?

 

[mwr]

6 minutes ago, murphy said:

Are you inserting the key (screwdriver) in the hole in the bottom of the cap?

 

Yes, assuming there is only one hole, actually an open slot.

[agbva]

I've left my 18 FFH in the garage for 3 weeks at a time and it starts right up. I'm about to do this again for another upcoming set of consecutive trips, so it will be the 3rd or 4th time. No battery saver or anything connected. My 18 Ford owner's manual says to start the car at least once in 30 days, so if you a planning a 3 week trip, I'm not seeing the issue.

 

If you want a bit of extra security, take the manual part of the key with you and in the unlikely event that the car won't start and you need a jump, you'll be able to open the drivers door with the manual key thing and get under the hood for a jump

[Waldo]

I recently left my 2014 sitting for 3 full weeks.  It started right up and it's still got the original now 6.5 year old 12V battery in it.

Edited January 21, 2020 by Waldo

[Mac]

7 hours ago, Waldo said:

I recently left my 2014 sitting for 3 full weeks.  It started right up and it's still got the original now 6.5 year old 12V battery in it.

Thank you...that's encouraging. 

[Airlocker33]

My spare key has been in my car now for three years, no issues

[mmtphoto]

i have a lot of older cars that park outside so I have solar chargers on all since some don't get driven much-you can find 5, 7 and 10 watt panels on ebay or amazon, I hook them up directly to the battery and mostly place the panel on the rear shelf.  Never have battery problems and some of these cars get driven less than 1000 miles a year and can sit for over a month between starts.  Cheap investment and easy to install.