Battery access

[Twilloo]

Yes this is beating a dead horse, but the more I think about this battery access problem, the more I wonder what is behind door number 2. I know that a high tech first year car has all kind of glitches but this is not a glitch, this horrible battery access problem is a design flaw not a glitch. Tow truck drivers will not attempt to access the battery and many men and women will not either so a vehicle has to be towed in when a possibly easy jump would have got it going. I am elderly and not sure I even have the strength to pull those panels off. Has anybody got in good advice of how to get those panels off without breaking or losing the clips that hold them on. I would really appreciate any help.

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[Ride_the_lightning]

Took me about 6 minutes to complete the project listed in another thread and add access holes so I can jump start it myself. I then taped a $4 12V battery behind the bumper to open the frunk, and put my mobile jump starter in the frunk. Total cost about $18 for a hole saw bit, plugs and those batteries plus the cost of the mobile jump starter ($80).

That said, I agree it’s a stupid design by Ford and this shouldn’t be necessary, but it is, and at least it’s an easy fix if you think of it ahead of time.

 

[ChasingCoral]

Took me about 6 minutes to complete the project listed in another thread and add access holes so I can jump start it myself. I then taped a $4 12V battery behind the bumper to open the frunk, and put my mobile jump starter in the frunk. Total cost about $18 for a hole saw bit, plugs and those batteries plus the cost of the mobile jump starter ($80).

That said, I agree it’s a stupid design by Ford and this shouldn’t be necessary, but it is, and at least it’s an easy fix if you think of it ahead of time.

Nice! I didn't realize these little 12V batteries existed. I'm going to order one.

For opening the panels, these trim removal tools are great and dramatically reduce the amount of muscle required to remove the panels. I keep a set in the frunk.

https://smile.amazon.com/gp/product/B079SDN553/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&th=1

 

[DaMeatMan]

Took me about 6 minutes to complete the project listed in another thread and add access holes so I can jump start it myself. I then taped a $4 12V battery behind the bumper to open the frunk, and put my mobile jump starter in the frunk. Total cost about $18 for a hole saw bit, plugs and those batteries plus the cost of the mobile jump starter ($80).

That said, I agree it’s a stupid design by Ford and this shouldn’t be necessary, but it is, and at least it’s an easy fix if you think of it ahead of time.

I had seen this discussed before, but has anyone actually confirmed that these cells can deliver enough current to trigger the trunk release mechanism? I'm fairly certain someone tested with a bench power supply and mentioned you need about an Amp of current which these cells definitely cannot deliver.

It's a great idea, and I had similar thoughts, but without actually disconnecting your LVB and then testing if these cells have enough juice to pop the frunk, it's really a false sense of security if they can't get the job done when really needed.

 

[Ride_the_lightning]

I had seen this discussed before, but has anyone actually confirmed that these cells can deliver enough current to trigger the trunk release mechanism? I'm fairly certain someone tested with a bench power supply and mentioned you need about an Amp of current which these cells definitely cannot deliver.

It's a great idea, and I had similar thoughts, but without actually disconnecting your LVB and then testing if these cells have enough juice to pop the frunk, it's really a false sense of security if they can't get the job done when really needed.

That’s a good point. I have not confirmed that, and my assumption was based on people opening their Tesla frunks with a 9V battery. I have no idea if the MME and Teslas have similar opening mechanisms. Would sure be nice to have an answer.

 

[DevSecOps]

Here you go:

https://www.macheforum.com/site/threads/guide-better-jump-point-access-battery-access.10976/

 

[louibluey]

I had seen this discussed before, but has anyone actually confirmed that these cells can deliver enough current to trigger the trunk release mechanism? I'm fairly certain someone tested with a bench power supply and mentioned you need about an Amp of current which these cells definitely cannot deliver.

It's a great idea, and I had similar thoughts, but without actually disconnecting your LVB and then testing if these cells have enough juice to pop the frunk, it's really a false sense of security if they can't get the job done when really needed.

We know that 8 AA batteries work, and Lithium are recommended for those in cold climates. We can look up the specs for those small 12V batteries to see if they can deliver just over 1A.

I strongly recommend that you do not try two of those 12V batteries in series for 24V (unless Ford says otherwise).

Those relatively heavy leads also power a micro computer. The initial load current is very low, something like 40k ohms initial resistance. The micro runs the process that will turn on some switching element (MOSFET, relay, etc.) to power the motor (just over 1A each time) twice with the correct timing, to get the double open mechanical pull. 18V or 24V might damage the low level electronics (unless Ford says otherwise).

Here is a picture of the frunk release motor: Battery for Frunk Release to store in bumper

 

[Twilloo]

I had seen this discussed before, but has anyone actually confirmed that these cells can deliver enough current to trigger the trunk release mechanism? I'm fairly certain someone tested with a bench power supply and mentioned you need about an Amp of current which these cells definitely cannot deliver.

It's a great idea, and I had similar thoughts, but without actually disconnecting your LVB and then testing if these cells have enough juice to pop the frunk, it's really a false sense of security if they can't get the job done when really needed.

Thank you, did you cut out the holes with the covers in place or did you take it off? thanks

 

[louibluey]

That’s a good point. I have not confirmed that, and my assumption was based on people opening their Tesla frunks with a 9V battery. I have no idea if the MME and Teslas have similar opening mechanisms. Would sure be nice to have an answer.

We know that in many cases a 9V battery will not work: Frunk Bumper Release 9V battery does not work, 12V works

 

[louibluey]

That 12V battery (typically used in garage door wall mounted keypads) will not work. The load to run the frunk release motor was on the order of 1.2A which is about 10 ohms for 12V. Two in parallel will likely not work as well.

Two of those little 12V batteries in series might damage the electronics (there might well be a high voltage 24V during the initial high resistance 40k, before the power switch closes in sequence to cause the two about one second activations of the frunk motor release).

Just use 8AA in series, or some kind of 12V gel cell battery. Or, a 12V jump pack, or hail a nearby or passing motorist with 12V jump cables.

The little 12V cell has an impedance of 22 ohms, so the initial voltage divider alone of 22 ohms and 10 ohms will drop the voltage across the motor too low.

 

[DaMeatMan]

We know that in many cases a 9V battery will not work: Frunk Bumper Release 9V battery does not work, 12V works

Yes and that very same thread is the one I was referencing above when I mentioned that operation of the frunk release mechanism requires about 1.2 amps @ 12v.

Those small 12v cells that were taped to the inside of the emergency frunk release cable access port on the front bumper cannot provide any more than 15ma - 25ma at best, which does not even come close to what's required to release pop the frunk. Those small cells are nothing more than several button cells (watch batteries) in series to provide 12v, but at extremely low current capacity.

With that said the conclusion to the testing done in that thread was that 8 AA's in a 12v series configuration battery holder seems to be the safest most reliable solution available.

Example of what I'm talking about:
https://www.amazon.ca/Battery-Thick...d-d0fcc598df1c&ref_=pd_gwm_ci_mcx_mr_hp_atf_m

You (might) be able to get away with doing the same thing with 8 AAA's, but I'm not sure they can (reliably) deliver over an ample of current, but may test this myself some time.

 

[louibluey]

Yes and that very same thread is the one I was referencing above when I mentioned that operation of the frunk release mechanism requires about 1.2 amps @ 12v.

Those small 12v cells that were taped to the inside of the emergency frunk release cable access port on the front bumper cannot provide any more than 15ma - 25ma at best, which does not even come close to what's required to release pop the frunk. Those small cells are nothing more than several button cells (watch batteries) in series to provide 12v, but at extremely low current capacity.

With that said the conclusion to the testing done in that thread was that 8 AA's in a 12v series configuration battery holder seems to be the safest most reliable solution available.

Example of what I'm talking about:
https://www.amazon.ca/Battery-Thick...d-d0fcc598df1c&ref_=pd_gwm_ci_mcx_mr_hp_atf_m

You (might) be able to get away with doing the same thing with 8 AAA's, but I'm not sure they can (reliably) deliver over an ample of current, but may test this myself some time.

A AA battery holder could be good (long term corrosion might be a problem, although you could put the battery holder empty in a zip lock bag, and leave two packages of unopened AA batteries). @CHeil402 suggested a similar battery holder. Although expensive, I think his idea to store AA lithium batteries for longevity and cold weather use is probably best. OTOH, if you are near a store, just buy two AA 4 packs if you need them quick to open the frunk.

Nothing special about the plastic pipe idea, just a way to hold the 8 batteries in a row and connected to each other. Heck, in a pinch, you could fold a 90 degree bend in a section of cardboard and line up the AA batteries in the angle fold.

 

[murphy62]

I took a different approach.

I installed a 30 amp fused cable by connecting one end to the jump points and routing it to the door in the bumper. I installed a power pole connector on the end of the cable.

I put a 12 volt 7 ampere gel cell battery in the frunk and routed a cable from it to the door in the bumper. It also has a power pole connector on the end.

I installed a power pole connector on the ends of the existing connections behind the door in the bumper.


Open the frunk with a dead battery.
Connect the gel cell power pole to the power pole for the existing connections.

Charge the battery with an external smart (knows what AGM is) battery charger.
Connect the external charger to the power pole going to the battery.

Give a boost to a weak but not completely dead battery.
Connect the power pole from the gel cell to the power pole from the battery.

Power pole connectors are available on Amazon.

https://www.amazon.com/Powerpole-Co...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==


Yes I have a power pole pin crimping tool.

In case you aren't familiar with power pole connectors they do not have a sex. Any connector can connect to any other connector as long as the red and black connectors are matched at the connection.

 

[Maquis]

That 12V battery (typically used in garage door wall mounted keypads) will not work. The load to run the frunk release motor was on the order of 1.2A which is about 10 ohms for 12V. Two in parallel will likely not work as well.

Two of those little 12V batteries in series might damage the electronics (there might well be a high voltage 24V during the initial high resistance 40k, before the power switch closes in sequence to cause the two about one second activations of the frunk motor release).

Just use 8AA in series, or some kind of 12V gel cell battery. Or, a 12V jump pack, or hail a nearby or passing motorist with 12V jump cables.

The little 12V cell has an impedance of 22 ohms, so the initial voltage divider alone of 22 ohms and 10 ohms will drop the voltage across the motor too low.

While I agree that this battery won’t pop the frunk, you can’t use impedance @1 KHZ in a DC voltage divider calculation without knowing the resistive component.

 

[Ride_the_lightning]

While I agree that this battery won’t pop the frunk, you can’t use impedance @1 KHZ in a DC voltage divider calculation without knowing the resistive component.

I agree, and also probably agree that my small 12V battery likely won’t work given the 1.2A current draw. I am an EE but took the lazy way out on this one since I didn’t feel like taking apart the frunk to get to the battery, I’m glad to see somebody else already did and got some data on the release mechanism current. Maybe in parallel with a capacitor on a small circuit board, but I’d have to do the calculations to see if that would even come close to providing that level of momentary current. Anybody more motivated than me to pull out their college textbooks? I’ve gotten lazy in the middle part of my career.

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