Okay... I finally looked INSIDE the back end by the HV battery air intake and cooling system.

Sure enough! There ARE two 1" rubber WATER hoses in there!

Only they are not heater hoses... but I could see how a new 2007 owner could have made that mistake.

One rubber hose is a condensation drain line from the A/C heat exchanger.

The second rubber hose is a water drain line from the outside window vent.
All the water will collect at the low spot and harmlessly drain out.
If rain, or water from a Car Wash did go in the window vent, it would not make it to the battery under any condition. ( unless the drain hose was plugged, which is totally possible I guess )

Both hoses connect at a "Y" and drain out one hole in the bottom of the chassis. If you look under the rear of your FEH, near the A/C lines ( 2 silver metal lines with rubber fittings ) but a couple inches towards the front, you will see the drain hole... with an oval shaped rubber gromet.

In the past, people in wet climates sometimes had door jams, window jams, trunks, etc. rust out when drain holes got plugged with dirt or debris like dead leaves, etc. So if you rarely wash the undercarriage of your FEH, and/or you drive in dirt / mud / snow / ice sometimes, you may wish to hose it off and check the drain hole for the HV battery and rear window vent. Since this is kind of important... I'm half way surprised it's not mentioned in the scheduled maintenance section... like "check the drain hole every 10,000 miles, or when you do filter changes". The other half of me said don't be surprised... this is Ford after all...

So that is ONE mystery solved about the FEH...

 

This is from the '07 FEH owner's manual on page 206.

"Engine block/high voltage battery heater (if equipped)

"An engine block/high voltage battery heater warms the engine coolant and high voltage battery cells which aids in starting, vehicle performance and heater/defroster performance in cold weather."

Apparently the heater accomplishes a variety of tasks.

 

Some of you have seen these photos and one of these is from Gary G in a previous thread. One is the internal view of the hybrid battery--the case top is removed. The second is a diagram/photo with FORD identication parts of the hybrid battery. Do you see the words "heater control" at the bottom of this diagram/photo?
fordinternalbatteryheater-1.jpg?t=1201317219

fordescapehybridbatteryopened.jpg?t=1201317262

 

So if I see wires coming out of the area near the heater control on my '07 FEH I can assume that I just need to buy the wire assembly, heater assembly and charger assembly to attach up front?

 

Here, this will explain A LOT!
I'll bet you all want a battery heater now!
-John

 

Well I added the HV warmer to my block heater and now I am seeing 2% higher SOC from regen braking on my normal trips. The ICE charge limits seem the same 52.9% but I am now seeing 56.5% and almost 57% Tomorrow it supposed to be 35'F so I will see how it does in the morning.

 

Are you talking SOC? The 53% SOC limit for generator does not change for mine based on temperature. Check out MxC, MxD, and Tav over the next few days and see how they compare to my chart. I expect they would be the same +/- 3 amps either way, wouldn't you?

 

Yes SOC but for regen, the ICE charge limit is still 53% but it seems to be accepting a higher charge rate from the regen.

 

Mine did it again....

Outside air.... -6'F
Tav.... 49'F
CHT... 188'F
IAT... -1'F

Cruise control.... 60 MPH

And the battery went 53%, 49%, 53%, 49%, 53%, 49, 53% within 5 miles of steady speed on flat roads and warmed itself up to about 57'F.

Then I got to the city / mall and the car went EV and I was crusing the parking lots in EV at -6'F.

This A.M. ( thanks to plug-in heaters ) I had EV after first 5 minutes...
at -9'F.

REGEN WAS BASED ON BATTERY TEMPERATURE, NOT OAT.
EV WAS BASED ON CHT, NOT OAT.

 

John
What is you initial battery temp after you heater has been on when it is below 40'F. Mine was 46'F when the outside temp was 33'F after all night on the heater. For got to chech this morning but after 2.5 miles it was 69'F and it was 52 this morning OAT (not the car) Are these HV heaters kinda weak?