John and Willard

The above is right out of the '05 FEH workshop manual page 414-03-31 which says "the vehicle (and the HVTB) must be at room temperature for the jump start proccedure to have optimum effect". We were not talking about how much power can come from the HV battery when it's hot (140F) or how high the battery can be charged cold as you both are pointing out. I don't agree or disagree because that subject is not what we are talking about. The HVTB can charge and discharge very rapidly for EV mode, but this is effected by both cold and heat. The only way to heat the battery in cold weather is to charge it, there is no HV battery "heater" provided that I have seen ref. anywhere. If you disagree, please provide us the documents like I do.

Anyone who has driven the FEH knows we get into problems charging the HVTB in too cold or too hot conditions. This is mainly with the high charging effects of "L" regen. It appears to me from the manuals in many places that the HV battery work better in the range between 77F to 100F with 82F being optimum.

GaryG

Chemicals not allowing FAST charging does not mean that a higher charge cannot be reached for a COLDer battery, just that it takes longer to charge it to the DEEPER level.

Have you made allowance for the battery plates being closer together the colder the battery is...?

I don't think the difference would be significant. However, as I understand things, both are right in some sense of the word. A COLD battery will produce less current when it is drawn on because the chemical reactions are temperature dependent. A HOT battery will have a high internal resistance and will therefore have a larger voltage drop when current is drawn from it. The battery will operate best, somewhere in the middle.... not at the two extremes.

Sadly, the HV traction battery must be replaced as a whole, drop-in unit if defective... not even a Ford Authorized Technition is allowed to repair it.

Thus, there are no drawings, pictures, or schematics of what is really inside the sealed battery compartment.

So we are going to have to wait until some owner exceeds his/her warranty period, and has the guts to take one apart and post pictures.

I know I will be taking mine apart if/when I reach 150,000 miles and there is no chance of me loosing warranty status.

Just for Gary ( And I know he has already seen this... )
Under PinPoint Test LTC B1016 - Jump Start Control Module
Under "Normal Operation" it states the low voltage battery is used in an 8 minute process to HEAT and step up the voltage of the HV battery pack.

I have the CD-ROM so there's not an actual page number, but it is under Section 414-03.

-John

In my copy of the 2007 shop manual, section 414-03, the only reference I could find to the operation is "Also contained within the HVTB is a low voltage charger that is used during the jump start procedure. For additional information about the jump start procedure, refer to the Owner's Literature."

John, PinPoint Test L: DTC B1016 - Jump Start Control Module Fault must have been changed in the '05 manual to read: Under "Normal Operation" it states in section 14-03 page 31 "the jump start button is momentarily pressed, the jump start control module within the HVTB uses the low voltage battery during a 10-minute process (8-minute charge plus 2 minute rest) to step up the low voltage in an effort to charge the high voltage battery to the point where it may start the engine. This page is also where it talks about room temperture I've been quoting. Your '04 CD-ROM maynot be for the first '05 model FEH, but an earlier CD that was available that was changed in the printed version of the '05 FEH Workshop Manuals.

John, I would call Helms and ask for the updated '05 CD ROM since the '04 CD is incorrect.

Thegreatescape, my '05 manual reads the same as yours under section 414-03 Description And Operation on page 414-03-2.

GaryG

Until then...

Best single LD trip: 35.3mpg

"...room temperature for optimum effect..."

Engines are VERY hard to turn over for starting after a night setting out in the cold in the wintertime in Anchorage...

The room temperature may not have any meaning insofar as the battery alone is concerned at all. For "optimum" jump starting I would want the engine "warm" and the battery "cold", so room temperature seems to be a reasonable "optimal, in the middle, optimal point.

And, if the battery were to perform best at 140F why waste fuel running the A/C to cool it? Anyone know at which point, hybrid battery temperature, the A/C begins cooling the hybrid battery?

Cool yes (as in 80F or something like that).... not COLD. Try putting your flashlight batteries in the freezer for a couple of hours and then see how bright that flashlight is.

I believe the FEH attempts to use outside air first (opens the rear vent door and activates the fan), to cool the batteries. Only if that fails, then finally activates the A/C coolant loop as its final attempt to keep the batteries cool.

Best single LD trip: 35.3mpg