Originally Posted by GatorJ

This is, I believe, a summary of the collective thread wisdom for the procedure. I added a few notes/thoughts. Usual disclaimers about don't try this at home, hire a professional, risk of electrocution/death, etc.

Note 1: the entire battery casing is plastic, only the covers are metal, as are the points where the screws go in. You don't want to damage the casing by over tightening anything or prying up on it.

Note 2. it is essential for proper battery cooling that the HVTB covers fit and seal properly, do not bend them and do not damage any seals.

Note 3. EVERYTHING can be done with the battery in place in the vehicle.



Safety is obviously foremost. .

IMPORTANT: The charger described in this thread produces approximately 380 volts, but at low amperage. The two ring connectors are exposed on the short harness that attaches to the HVTB battery relay. NO NOT TOUCH those if that harness is connected to the charger and the charger is plugged in. There would be no reason for you to connect that harness to the charger until AFTER it is installed on the HVTB. I purchased red 3D printed safety caps to protect the female connector of the short harness.

Be very familiar with the photo of the relay block in post #53. He circled the positive and negative connection points on the relay block in red(+) and black(-). The terminal ends on my harness are color coded the same way, which is obviously the standard.

IMPORTANT: Remove the big orange service plug from the HVTB when working on it.

Needed:

Security Torx bits
Trim panel tool
Ratcheting screwdriver with bits.


I would suggest you go in this order:
1. Disconnect 12 volt battery, put it on a charger.

2. Remove orange service plug from HVTB

3. Completely remove trim pieces in rear cargo area. Here's a good YT video (Note: he made a mistake at 1:04...open that little cover and remove the fastener from there, not the way he did it, and you won't break it.) You will need a trim tool. Both sides are similar.:
https://www.youtube.com/watch?v=QKi6mH1wE3M


4. Remove HVTB AC vent. Note: scroll down for 09+ models:
https://www.dropbox.com/s/85demexnlo...draft.pdf?dl=0

5. Remove large cover fasteners . Note here is a video of a guy opening up a battery after it has been removed from the vehicle showing you bolt placements. You, of course, are going to be doing this in place. The top ones are easy...super easy access. There are two bolts on the sides of the lid about mid-battery with straps attached (0.48 of video). You can get to those with channellocks. Moving toward the front of the vehicle, also on the sides of the lid, are 2 more bolts (0.56). Those are the hardest ones to get to. Use one of these tools and cut down the bits to make them shorter and it will fit.
https://www.amazon.com/KAIFNT-Screwd...s%2C162&sr=1-9


Then remove the final two bolts on the front edge of the lids (1.04). Super easy access with rear seat moved out of the way

https://www.youtube.com/watch?v=-V7pqzosJpM


6. At this point you should be able to remove the large cover towards the front of the vehicle.

7. Access the relay in the HVTB per post #1.. There are written directions and high quality photos. Here's a YT video of someone who has opened up the HVTB in place in the vehicle and is getting ready to install a harness.::
https://www.youtube.com/watch?v=KkhwmdR_t5U

8. Attach the short harness per the photographs paying close attention to polarity.

9. Reassemble relay into HVTB


10. Route the harness out of the battery so that the female connector with the red safety cap is hanging outside the HVTB casing. Consider notching the casing as you don't want the lid to cut into the harness and short out the HVTB. That would be the definition of a bad day.

11. Reinstall HVTB lid being mindful of torque specs.

12. Reinstall duct for HVTB AC system.




CHARGING PROCEDURE:
Remove orange service plug completely
Remove red relay harness safety cover
Connect charger to relay harness
Plug charger into 110VAC supply
Install orange service plug
Charge for 4 hours
Remove orange service plug
Unplug charger power from 110VAC supply
Unplug charger from relay harness
Install red relay harness safety cover
Install orange service plug
Reinstall/connect 12 volt battery
Clear any codes from vehicle with scan tool or equivalent.
Start vehicle, allow to run until ICE shuts off and vehicle goes into HEV mode.
Thank S Keith. This all started with his ingenuity.

At full charge under a low current (0.5A), the FEH battery will be full at between 353-358V (approximately).

Originally Posted by Ajvanek

I'm about to attempt to save my mom's 2009 FEH. From my understanding, this harness is permanent correct? It will hang outside the battery cover? I haven't had time to read through the whole forum just yet - I've been skimming for photos, videos, and written tutorials.

Originally Posted by NDunfiltered

Are you aware of what might make it so that the push button in an ‘07 Escape Hybrid wouldn’t light up or work to charge the battery? Does it mean the battery is completely dead? I have it at a shop right now and they changed the PCM and I was hoping that would resolve the issue but it hasn’t. Now they’re referring me to a dealership to have that HV battery charged but I thought that’s what the push button was for - so the question is — why is the push button not working?

Originally Posted by elborak

My 2009 FEH has been having some self-drain issues. Nothing too serious if driven regularly, but it will be sitting undriven for the month of December, so I decided to install a connector for an external charger should I return to a depleted HVTB.

Process went smoothly (I think) thanks to S Keith's detailed instructions (plus GatorJ's followups). I have a few small suggestions I'll post that might help others, but I do have a question first. After reassembly and restoring power, the car seems to drive fine though it will need to be driven a bit to clear P1000. However there is also a P0AA7-60 code. Could I have a bad connection on one of the ECU wiring harnesses? Those things are ****ed tight and took some significant force/twisting to get reconnected.

Thanks.