Battery access

[Maquis]

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.

I’m also an EE. If you think it’s bad now, wait till you retire! ?

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[louibluey]

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.

To be rigorous (another semi-retired EE, yes the 22 ohm impedance remark was a mistake), I think the next step would be to record the current and waveform with a digitizer (A Keysight DMM would do fine). I think with a Fluke 376 DC clamp on meter (older version without logging), I saw about 1.2A twice for about 1 second.

The odd part was the initial 47k ohm input resistance, which I take to be the electronics board (mostly likely including a micro) that controls the switch (relay) to the release motor. So, it takes very little current to power up the timing and control board/module, but then enough power (raw or stored) to drive the frunk release motor twice (picture below).

I may have done something wrong, but I could not get that circuit to enable/run by simply lifting the 12V LVB ground. I had to pull the F72 VBATT fuse for the 12V input to that module, which is in the frunk fuse box (the battery junction box, BJB), so you have to pull the frunk tub first (not a show stopper, I guess I can do that quickly now). The fuse and circuit is in that initial thread. Once I pulled that fuse, the override/frunk release wires in the bumper were active. Fuse F72 to simulate dead/low 12V LVB Diagram: schematic showing F72. more schematics. It started to make more sense here. (I was pestering Greg @SnBGC every 5 minutes for more schematics during the project last March, and he graciously provided them each time)
One of the early threads hashing through the emergency frunk release: Battery for Frunk Release to store in bumper

In the end, I opted for a simple mechanical release cord: Indiana Jones and the Emergency Frunk Release

The actual waveforms might be interesting, but I am not sure how much more there is to measure or calculate. I guess through careful analysis we could define a more exact amount of power/energy required, say whether AAA would work or just AA batteries. Is it interesting enough to make more study of the frunk release, not sure?

The frunk release motor (runs twice to open)

 

[Twilloo]

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.

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.

The battery access project is very easy and thanks to all who gave me pointers on how to best do it, but I do need a little more advice to make it really perfect. I cut 2.5 in holes and got 2.5 in hole plugs and they fit too perfect as they are snug but not tight and I feel as if they will vibrate loose. Any ideas as how to tighten them some and also some way to be able to get them out with ease as the fingernails will not work once it is a little tighter and I do not want pry marks. thanks again to all for your help.

 

[Ride_the_lightning]

The battery access project is very easy and thanks to all who gave me pointers on how to best do it, but I do need a little more advice to make it really perfect. I cut 2.5 in holes and got 2.5 in hole plugs and they fit too perfect as they are snug but not tight and I feel as if they will vibrate loose. Any ideas as how to tighten them some and also some way to be able to get them out with ease as the fingernails will not work once it is a little tighter and I do not want pry marks. thanks again to all for your help.

I used 2” plugs, and they are pretty tight. I put a small flat head screwdriver in the frunk with my jump starter.

Still need to decide on how I will get the frunk open though.

 

[Twilloo]

I used 2” plugs, and they are pretty tight. I put a small flat head screwdriver in the frunk with my jump starter.

Still need to decide on how I will get the frunk open though.

right, thanks. will one of the brick size battery boosters work to get frunk open

 

[Ride_the_lightning]

right, thanks. will one of the brick size battery boosters work to get frunk open

Absolutely. That’s what I have. Unfortunately it’s…..in the frunk.

 

[Twilloo]

Absolutely. That’s what I have. Unfortunately it’s…..in the frunk.

yes I know, me too, I thought about marketing a power booster holster that we could wear around everywhere, that way we will always be prepared lol

 

[Ride_the_lightning]

yes I know, me too, I thought about marketing a power booster holster that we could wear around everywhere, that way we will always be prepared lol

So far I have had no issues with my 12V, and I’m hoping the cases we hear about are isolated incidents. If they aren’t, I will be concerned, because I have never, ever, in my entire life, had a 12V battery in an ICE car become so dead that I couldn’t open the doors and turn on ACC mode. Plenty of times they have died and prevented me from starting the car. I’ve jumped cars countless times in my life. But that 12V lead acid battery always had enough to let me in and play FM radio, even after a week of being buried in the snow in Colorado.

I’m hoping the extreme temp is the variable here. I’ve been in cold, but never THAT cold. 0F is cold here, and even in Colorado it rarely dipped below 0F. Single digits mainly. If my MME is reliable in single digit F temps, I’m fine (but still feel for you Canadians). If it’s not, then Ford undersized this battery and should just stick a full size ICE battery in this thing and call it good.

 

[JSW]

I had a major 12v issue last year (November 2020 build).
In my view, it still isn’t right.

I initially ran a quick charge cable through the vent for easy access (see pics Below). Easier access would be to run the 12v quick charge cable to the front bumper access.

 

[dtbaker61]

I had a major 12v issue last year (November 2020 build).
In my view, it still isn’t right.

I initially ran a quick charge cable through the vent for easy access (see pics Below). Easier access would be to run the 12v quick charge cable to the front bumper access.

a battery tender hooked up to front access port won't do you any good at all. you MUST use the 'connection points' under beauty cover..... but if your HV is not charging the LVB when it hits 11.9 automatically, then you should get it actually fixed. Battery tender should NOT be needed.

 

[dtbaker61]

I used 2” plugs, and they are pretty tight. I put a small flat head screwdriver in the frunk with my jump starter.

Still need to decide on how I will get the frunk open though.

the same kind soul that is going to give you a 'jump', just uses the jumpers on the bumper port wires to pop the Frunk.... THEN gives your MME a jump; only make sure they leave the jumpers connected for 10-15 minutes to get a good bit of Energy into the LVB before you try to turn it on.

 

[generaltso]

a battery tender hooked up to front access port won't do you any good at all. you MUST use the 'connection points' under beauty cover.....

He's talking about running cables from the connection points to the access panel in the bumper, not using the cables that are already there for popping the frunk.

 

[Ride_the_lightning]

the same kind soul that is going to give you a 'jump', just uses the jumpers on the bumper port wires to pop the Frunk.... THEN gives your MME a jump; only make sure they leave the jumpers connected for 10-15 minutes to get a good bit of Energy into the LVB before you try to turn it on.

While I have been jumped several times in my life by nice strangers, in almost all circumstances I have supplied the jumper cables. They usually say something like “I’m so glad you know how to do this because I would have no idea!”

The fact that Ford is making me rely on random strangers being prepared does not make me feel very prepared. Roadside assistance is an option of course, but if I’m 5-10 miles from home I’d rather jump myself and be on my way rather than wait 30+ minutes for a tow truck to do something simple.

 

[RickMachE]

He's talking about running cables from the connection points to the access panel in the bumper, not using the cables that are already there for popping the frunk.

This ^^^

If you buy a Battery Tender, you can then buy an extension, either 6 or 25 feet, which allows you to run it pretty much anywhere.

On my F-150, I run from the battery, across the front of the car, and down into the left front wheel well, because that's what I can access with the truck pulled into the garage. When not in use, I tuck the end of the cable up into the wheel well, so the end doesn't get covered in snow/ice/slush. It popped out once and wore off the connector's cap hitting the tire. The company sent me a few extras, I own 3 Battery Tenders.

Based on others having issues, I will probably set mine up soon, and at least connect it every now and then, although even today with temp this morning below zero (now around 8), my garage right now is 26, at least on the thermometer mounted outside the door.

I haven't studied the Mach-E, but likely running it to that port won't work for me, because that would mean I have to squeeze around the front of the car to connect it. Also, that port is not made to be opened and closed all the time. I'm going to look and see if it's feasible to run it to the charging port, but I don't want to drill through the plastic there. More likely is the left wheel well...

 

[Carsinmyblood]

Has anyone thought of installing a simple pull handle hidden in the wheel arch or under the car.

It's just a cable. No batteries, wires or computers. It sisters the release cable in the car.

When hot rodders set up their cars with hidden electric door poppers and power trunk lifts, we ALWAYS install a mechanical release in case of battery failure.

I built 3 of them into my '34 Ford. One for each door, and the trunk. We also install emergency battery posts for jumping as our batteries are under the floor.

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