Hi there,
I have XE 2017 25t model, and during my travel, battery went flat.
I have opened the door(with key) and hood, connected jump cables, but car system doesn`t boot, and I cant unlock trunk with key or button.
I can`t access trunk because my model doesn`t have folding back seats.
When I connect jump cables to a running vehicle for quite long time (30minutes+), eventually, car system still doesn`t boot,
however car triggers alarm and screams, which, I can`t seem to shut down. Don`t think neighbors would appreciate car screaming for hours.
So, is there anything I can do in this situation to power car`s system so I can unlock trunk, and replace/charge battery? Will alarm eventually stop?

 

Jump pack on the terminals under the hood. That usually does thr trick. If that doesn't trigger, you can locate the trunk release wire on the ecu harness and backfeed 12v to pop the trunk.

 

Someone went through something similar on the F-type forum recently, and their jump pack, like a battery maintainer, needs some voltage to be present on the battery or it won't power up. Jumping from a running vehicle (or a strong battery) should be the best chance of working, I would think. It sounds like your XE battery is super-dead rather than just very weak. If you don't have heavy-duty (thick gauge) jumper cables, see if you can borrow some. With as much current as it sounds like it's drawing, thick cables and good contact with the clamps is a must. Putting the negative side of the jumper cables to the chassis ground stud rather than the jump negative might help (or not.)

Don't know if there's anywhere around the rear seat or shelf where you could get an endoscope into the trunk, to pull the emergency release. If so, that would be easier than Crackberrie's suggestion of tapping into the harness (which someone on the F-type forum had to do, with a convertible, disconnected battery and disconnected CJB (central junction box)).

 

wait.... Removal of the rear seat rest is an option to reveal a way to get a wire to hook the emergency trunk release. looks like from some pictures there's a gap with cross bracing to get thru. @DJS sparked it and go on a photo hunt and you will see some info in shop manuals.