You CAN do this. This HAS been done. You can do this by the "brute force" method. ( electronically )

Ford reports the calcuated SOC slowly ( at a low Hz ).
You add in your own "talker" or CAN transmitter that talks fast. ( at a high Hz ). The FEH "sees" 100's or 1000's of YOUR data, and the real one piece of data gets lost in the noise, or is ignored as an "outlier" or whatever. The FEH "believes" the 100's of your data, which match, and not the one real piece of data, which is "different".

What you can do is "lie" to the car and make it do what you want.
Tell the FEH the SOC is 65% and it will give you EV when the real SOC is something very low, even in the 25% range. Tell the car the SOC is 35% when it is really 65%, and the FEH will start charging.

Now, I know this works from "trial and error" but know less about why it works. Just it works.

Is any of this good? Well, yes and no. Good for MPG? YES. Good for the life expectancy of the battery? NO!

I've read that the NiMH cells used in these cars, can take about 10,000 charge-discharge cycles. But that refers to 10,000 times to fully charged, to fully depleted. One can infer, that the cells will last 50,000 cycles from 40% to 60% ( or 100,000 cycles from 42% to 53% where the car spends most of it's time )

Lastly, to Bill, I was telling posters that the car will ALWAYS turn the engine on when the REPORTED or CALCULATED SOC is at exactly 40%. It never waits to 39%. Ever. The trigger, as you put it is indeed exact.
I never once claimed the exact true to life SOC was 40%. I never, ever, discussed anything other.

As far as for seeing a decline with age... this may be nearly impossible... by design. Since only 13% of the battery capacity is used on a daily basis... that 13% represents 235 watt-hours from a 1.8 kWh battery pack.
We may be getting 235 watt-hours from the "middle" of the pack when new, and it may take the full range of the pack's ability when old to deliver 235 watt-hours... but none of this will be seen in the first 15 years and / or 300,000 miles. None are yet this old, and few have gone the distance.

HTH,
-John

 

FWIW, I've lived in the same house for the past 9 years.
( Hence I drive the same roads on a regular basis. )
I've owned a FEH since mid-March of 2005.

I've done many, many endurance tests.
In 4.25 years and 84,000 miles, my FEH goes the same distance on the same roads in EV as it did when new. ( actually, less when new, more distance now, I should say it goes the same distance now, as it did after the "break-in" period of about 3000 miles )

So in truth, my FEH goes the same distance in EV at 84,000 miles as it did at 3000 miles. It still reports 40-53% SOC as the norm.

I'm curious now to try the 'recharge time' with a stop watch.
That's one test I've not done. It could have changed by a few seconds, but it's been nothing noteworthy in 4.25 years... but since the change is gradual... it wouldn't be noticable w/o documentation, so lets all start!

HTH,
-John

 

"It still reports 40-53% SOC as the norm."

Just as the software should. The issue is the chemistry in the battery and that will have to await extended real life experience.

I've posted previously that Pb-Acid traction batteries begin life at ~90% of rated, rise to a peak of around ~110% and then decline to ~80%, which is defined end of life for them. The reason is the way the chemistry improves for awhile as the battery is worked followed by the long term degradation of the chemistry inside the cell.

We just don't yet have enough experience to see how these NiMH batteries will perform over a "liftime."

When the "sensor" tells the software the battery is at 40% the software will start the ICE and recharge the battery. The key issue here is what is amount of energy in the battery when the sensor trips the software, not what the trip point is.

That is why I mentioned doing a repeatable test every so often to see if the amount of energy in the battery is changing.

Don't confuse the software set-point with the amount of energy available in the battery.

It took me awhile in previous posts to realize some were talking of the software set-point and not the chemistry of the battery & how the sensors & A-D converters worked.

 

I agree that, with a 13% band of charge-discharge, we may never see the equivalent of the Pb-Acid stuff I mentioned. Ford's selected band is just too small. So we'll just have to watch these.

 

I have a CBA-II and it ain't going to work on a 5.5Ah 330V Ni-MH pack even the HD model! I'm sure there is a tester for this but it's not available to consumers.

 

Your survey doesn't work with Firefox, and it doesn't consider the FEH - it speaks of sedans only and FEH isn't an option.