Where to keep a battery jumper?

[Scottmcll]

Like many, I have a battery jumper starter brick. In my old ICE car, I kept it in the car and plugged into a USB. I was doing the same in my beloved Mach-E since getting her in Jan., But after reading posts here re 12v battery failures, it finally dawned on me that keeping it in the car would do me no good since in all likelihood, I would be outside of the car when a battery failure occurs, right? So is the best option to leave it in my garage and hope that if a LVB failure happens I'm home? Am I missing something or is there a work-around? Just wondering what you guys are doing.

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[RickMachE]

That's it. And it needs to have a boost mode to work. You also get 5 years / 60,000 miles free roadside assistance...

 

[Maui]

Like many, I have a battery jumper starter brick. In my old ICE car, I kept it in the car and plugged into a USB. I was doing the same in my beloved Mach-E since getting her in Jan., But after reading posts here re 12v battery failures, it finally dawned on me that keeping it in the car would do me no good since in all likelihood, I would be outside of the car when a battery failure occurs, right? So is the best option to leave it in my garage and hope that if a LVB failure happens I'm home? Am I missing something or is there a work-around? Just wondering what you guys are doing.

Replace the battery at 3 years

 

[Kamuelaflyer]

Both of the above.

 

[markboris]

Only if the car was LOCKED when the battery dies are you unable to get in (after 12 minutes). If the car is unlocked, there is no problem opening any of the doors with a dead battery, even if the battery has been removed.

 

[Tomm]

There was a post a few years ago about leaving it in the trunk and then making a AA battery stick to jump the trunk, and THEN hiding the 8AAs under the access to the frunk leads.
Not sure if anyone did it but it was talked about.

 

[JohnFoxeSheets]

There was a post a few years ago about leaving it in the trunk and then making a AA battery stick to jump the trunk, and THEN hiding the 8AAs under the access to the frunk leads.
Not sure if anyone did it but it was talked about.

I think I might have gotten the holder for that, but I definitely never tested it out...

 

[Mach-Lee]

This predicament is why you should focus on the maintenance and replacement of the 12V battery instead. As the old saying goes, "An ounce of prevention is worth a pound of cure." Replace the 12V battery every 3-5 years or as soon as the app tells you. Then your chance of failure is very low.

My jump pack stays at home (not in the car). In the rare event my 12V were to die away from home, I would:

1. Ask around if anyone has jumper cables or a jump pack.
2. Call roadside assistance for a jump.
3. Call a friend or Uber for a ride home, and return later with my jump pack, cables, and/or spare battery.
4. If I'm in an area with no cell service (rare), use satellite SOS on my phone to summon roadside assistance or text a friend to come help.

The 8x AA's in series will work, but it's sort of a pain and I would not even bother with that. Your chance of needing it is slim to none if you replace your battery on time.

 

[Scottmcll]

This has all been very informative. Thanks to all!

 

[sbachman]

Only if the car was LOCKED when the battery dies are you unable to get in (after 12 minutes). If the car is unlocked, there is no problem opening any of the doors with a dead battery, even if the battery has been removed.

I'm surprised and curious about this. I would not have thought the doors would open without 12V power. Are there capacitors in the door latch circuits that allow this?
Apologies if this has been covered elsewhere; I'm relatively new to this forum. Thanks!

 

[markboris]

I'm surprised and curious about this. I would not have thought the doors would open without 12V power. Are there capacitors in the door latch circuits that allow this?
Apologies if this has been covered elsewhere; I'm relatively new to this forum. Thanks!

No problem Steven. Yes capacitors are in the door modules and will release the door latch when you push the button twice.

I work on my cars a lot (and many others) and frequently have the 12V battery disconnected for one reason or another. Never an issue opening the doors. You can open a door about 20 times before the capacitor is drained.

 

[RickMachE]

No problem Steven. Yes capacitors are in the door modules and will release the door latch when you push the button twice.

I work on my cars a lot (and many others) and frequently have the 12V battery disconnected for one reason or another. Never an issue opening the doors. You can open a door about 20 times before the capacitor is drained.

Yeah, but what if I want to do it 21 times?

 

[Chuck]

Here's the solution...

Keep the jump brick in the frunk.

Then you can open the frunk via the 12v lead in the front bumper. But you need a 12v source to open the frunk. So, where do you get the 12v source? Buy a 23A 12v battery on Amazon. They're cheap and about half the size of an AA battery.

Now, open that flap on the front bumper and pull out 1 of the 12v power leads. Put the 23A in a ziplock bag to keep it dry. Duct tape the bag to the 12v wire and stuff it back into the hole and replace the cover.

Done.

When your battery dies pull out the hidden battery and you can touch the two leads to the battery and the frunk will pop open.

You might think a thief can open the frunk now using the 23A battery. Not so. The frunk will only open using this method if the 12v is completely dead.

This is just an emergency method. As others have pointed out just replace your main 12v battery every 3 years. I replaced mine myself. Takes about 30 minutes. And don't let others try to convince you that you need to remove the frunk well to change the battery. You don't. I didn't.

 

[Maui]

Buy a 23A 12v battery on Amazon. They're cheap and about half the size of an AA battery.

the odds of that amazon battery being dead when you need it are higher than you getting locked out.

the couple free months on a 3 year old battery you might get is not worth the time and expense if you are wrong.

 

[E90alex]

Here's the solution...

Keep the jump brick in the frunk.

Then you can open the frunk via the 12v lead in the front bumper. But you need a 12v source to open the frunk. So, where do you get the 12v source? Buy a 23A 12v battery on Amazon. They're cheap and about half the size of an AA battery.

Now, open that flap on the front bumper and pull out 1 of the 12v power leads. Put the 23A in a ziplock bag to keep it dry. Duct tape the bag to the 12v wire and stuff it back into the hole and replace the cover.

Done.

When your battery dies pull out the hidden battery and you can touch the two leads to the battery and the frunk will pop open.

You might think a thief can open the frunk now using the 23A battery. Not so. The frunk will only open using this method if the 12v is completely dead.

This is just an emergency method. As others have pointed out just replace your main 12v battery every 3 years. I replaced mine myself. Takes about 30 minutes. And don't let others try to convince you that you need to remove the frunk well to change the battery. You don't. I didn't.

Those tiny 12V batteries don’t have enough amperage to pop the frunk latch.

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