Just to document in case someone else has a similar issue:

Starting about 3 weeks ago, my 07 FEH with about 32600 miles on it wouldn't go into electric only mode after it was "hot". It would work fine in the AM, i.e. after a few miles of warm-up, it would go into electric only mode for about the next 15 minutes when it should, but then it would never go into electric mode after those 15 minutes were up. In the hot Las Vegas afternoons, it might never go into electric only mode. There was also a very loud sounding rush of air in the back that I'd never heard before that loud. It appeared to me that the battery door was functioning normal. Of course, we weren't in the "orange/red" settings on the A/C, and I replaced the battery filter (for the third time since new, not an issue), and there were no "codes" displayed to me on the dash.

So, reluctantly I took it into the dealership (and provided a one page writeup describing exactly the issue, and how it wasn't normal since I knew what normal was after driving it for 3 years, and I gave them instructions on how they could duplicate it). I figured they would "CND" it (for you non-Air Force types, that means "Could Not Duplicate"), but low and behold, they duplicated the problem with diagnostic testing and said I needed a new HV battery

Fast forward one week, and they got the new HV battery delivered and installed it and ran diagnostic tests on it, and it is "clean". I picked it up just now, drove around for a while, and it seems to work normal (even with it being close to 100 deg outside). Hopefully it is fixed (knock on wood).

Total cost to me, $0 , but the receipt says $6895 for parts and $242 for labor .

At first I was P.O.'d about it needing a new HV battery, but perhaps I should feel lucky, in that I got a new battery for free after about three years on the old one, and hopefully the new one will give me an extra three years of use out of the vehicle.

Moral of the story: Since it didn't throw any codes or warnings on the dash, had we not known what normal was or had we not paid attention, we would have driven it around like this for a long time, thinking it was normal. It helps to pay attention to your vehicle and learn what is normal.

 

The inside of the hybrid battery pack contains "stuff" other than battery cells as shown in the photos. It is possible the cooling hardware/software may have malfunctioned causing the hybrid battery pack to operate incorrectly.

 

Those are great pictures showing the inner workings, and it certainly sounded like a cooling issue to me. I am not sure exactly what was wrong with the HVB, and it is real difficult to decipher the dot matrix gibberish, but it appears there was a POA81 error on a self test, and a fail code C27 and 2.3, and he states "PPT indicates faulty HVB". At this point, it seems to have fixed it, and I got a new, free battery, so I guess I don't really care exactly what was wrong with it.

 

For my '06 FEH if you go into the shop manual for the High Voltage Traction Battery, Section 414-03 and follow the diagnostic path, DTC P0A81 tests out the Hybrid Battery pack fan #1 control circuit. The subsequent pinpoints tests have several step out points that call for HVTB replacement.

It appears that the fan circuitry is not separately serviceable. I would hope that Ford returns these battery packs and services them for return to service.

 

I have heard that is the case about recycling. I know Honda and Toyota do.

I have also heard that so few packs have needed to be replaced, that the "spares" on the shelf are exceeding their shelf life, and prices have fallen dramatically. ( cut in half of what they put on your reciept )

Wholesale ( or dealer ) prices for the FEH packs are about $3k.
Packs for the Prius, about $2k.
Packs for the Hondas, about $1k.

If anyone ever needs a pack out of warranty, and they want to DIY, I know where to get FEH packs for $1500.00. Those firms converting to LiION and PHEV's have the OEM packs sitting on their shelves collecting dust, and they go "bad" in about 6 months without any maint. charge.

 

Man, hadn't heard that. I can't afford to replace any time soon, but when the time comes sign me up.

I figured they would be conservative and this is another data point confirming that.

Many thanks

 

Just a reminder that the Hybrid parts warranty is 8 years / 120K or 10 years 150K miles... before that Ford has to foot the bill.

 

Just ran across this report in 2008 about the FEH HV battery lasting over 300,000 miles so far in San Francisco taxis, so thought I'd pass the URL along:
http://jcwinnie.biz/wordpress/?p=3579