Okay, things have been going pretty good til this week. Then Tuesday I jump in the FEH (2006) and notice the SG is lit up.... weird. Start up the truck, back out of the driveway and look down as I start going forward, and my SOC is reading 6!!!! WHAT? As I drive to work, the ICE is running hard the whole way, the SOC slowly climbs to 36% by the time I get to work (~4 miles) and I shut it down. It has been sitting in the driveway for ~12 hours before I started it.

So later I run and do some shopping and pickup kids, the SOC climbs to 44 or so and everything starts working normally. I decide to keep an eye on it. Later that day as I am driving on electric only, the SOC gets down to 40, then bing bing the wrench light flashes a couple times as the ICE starts. Then everything works normal.

Since them I have been paying attention to what the SOC is when I park in the driveway, typically around 42. Wed am when we started it up, it was at 39, Thursday at 41 and then Friday at 26%!!!!

It has also done the flashing wrench light and bing sound as the ICE starts 3 more times this week. Related?? I don't know. It doesn't seem there are any codes stored, the wrench light goes off immediately and other than these two issues it seems to be acting normal.

We went on a fairly long drive this afternoon and evening, with several stops (shopping with the wife) and some big hilly runs (360 out of Austin) and average 39.9mpg for the day, some of the best mpg I have been able to get yet. (been averaging 30-32 per tank, mostly short trips)

Anyone had anything like this happen before or have any ideas where to start looking? Anything else I can watch to track down what is going on?

 

Sounds like an intermittent electrical short, perhaps in the DC-DC converter or maybe even in the generator or generator inverter. Did your vehicle start (turn over) with an SoC of 6? Or did it rapidly drop to 6 after starting normally? Is your 12V battery OK? If your SoC drops below 20%, a code will be set from the TBCM, but will clear if it does not stay there. Perhaps you are due for an SoC recal or pack re-balancing event. Try monitoring the module delta voltage to see if it ever goes above .12 or fluctuates wildly.

The Generator torque xgauge is as follows:

TXD:0745224976
RXF:046285490676
RXD:3010
MTH:000100010000
NAM:GTq

You might want to monitor this at start-up and when re-starting out of EV to look for any excessive values. Units are Nm. Should always be 0 when in EV.

 

I didn't notice til after I backed out of the driveway (short driveway)

? not sure - hadn't noticed any issues. it is a "36 month" battery and the vehicle is right over 3 years old, but I thought they lasted longer on these FEH since they don't actually crank the engine, right?

will do.

 

My car is 3.5 years old. ( Dec '04 build )
I parked it without use for 24 days.
( first time I've let it sit that long )

When I came home, and before starting, the HV battery SOC was showing 41 %..
That is normal.

What surprised me was the 12v battery was at 11.6 volts under no load other than dome light which sounds a little low to me. I too expected the 12v battery to last longer than average.

Thoughts?

A HV battery SOC of 6 should not start the car.
So maybe the module that reports SOC is malfunctioning.
Your MPG sounds really good.
Too good if you had a bad HV battery, but it is too soon to tell.
Keep us posted.

My ScanGauge lights up any time I open a car door, use the keyfob ( locking or unlocking), or otherwise "wake up" the car by opening the hood, etc. Mine does not require a key, or key-turn to "light up". It then goes out after about 15 seconds of no useage.

-John

 

To some extent that is normal... some battery chemistries (and I THINK lead acid is one of them) have a lifetime that is set by not only just charge discharge cycles, and depth of those cycles, but just on years since manufacture.

3yrs is, unfortuantely, not that unusual from a lead acid battery from what I've heard.

LiIon batteries (a very different technology to be sure) are pretty much goners 3 years from manufacture, even if all they did was sit on the shelf for all three years. You can beat them up with charge and discharge cycles.. and they'll die in three years as well. Its one of the limitations that needs to be overcome before they get used in plug in electric vehicles. No one is going to be happy about replacing a several grand LiIon battery every few years. That being said, I believe the manufacturers have found some ways to change the chemistry and improve that, but you'll notice it hasn't trickeled down to cell phones yet.

 

I have not had a chance to do any further testing yet, but the last few days we park the FEH with an SOC of 42 +/- 2, 8-10 hours later it is right around 32 +/-. Several times after starting it, the SOC falls down to 28, although I have seen it at 26 several times now.

Once I run 2-3 miles, the SOC gets up to 42+ and everything operates normal, we get around a mile EV @ 30mph on flat ground, etc. So something is running down the battery while it is parked.

I just got the SG about 2 weeks ago, so this MAY have been going on since we purchased the vehicle (6-8 weeks ago), as the more we monitor it, the more we are noticing the same results we have seen all along (see my "into" post)

I will try and find some time to test the suggestions above and let y'all know what I find.

 

The behavior to describe is not that unusual.
The numbers you report are unusual.

Check that you have exactly the correct codes in the ScanGauge settings.
You may be off by a single digit in the code.
Or, there is an outside chance there is a problem with your ScanGauge.
Can you rule out human error first?

My SOC drops several percent after each start-up also.
The car uses more electricity than normal when the engine first starts to allow some 'gentle' time on the engine while the engine and catalyist heats up.
This part sounds normal.

It should drop from the 50% to the 40%'s or from the 40%'s to the 30%'s.
It is very, very rare to get a 'normal' car lower than about 33%.

 

To get a mile of EV @30MPH you will have to start out your EV with at least 53% SoC. Does the ICE kick on at 39.9% SoC? When ICE cruising does the SoC hit 53% and more or less stay there? Do you have to have SoC at ~ 42 to go EV? How much does SoC drop when kicking on the ICE out of EV?
Overnite my SoC will drop ~.5%. Only time I have seen more than 1% drop was when I had the HV battery temp in the upper 80's from EVing, then the next morning the temp was in the 30's and the HV battery temp was in the 50's.

The fact that you did get a wrench light makes me think that you do indeed have an electrical problem. Even though it would only be a 20W drain, having it for 10hrs with the car parked should be affecting your mileage noticeably.

If you have 30MPH roads that you can EV and then charge you can quite possibly hit 60MPG with straight gas and well into the 50's with E10 provided you are out for 10 miles or more and the temps are in the 60's.

 

Sorry for the delay in answering, it has been a very hectic couple of weeks around here:

Yes, if the SOC is mid 50s I can get right around a mile in EV @ 25-30mph

"Does the ICE kick on at 39.9% SoC? "
YES, if I am driving very carefully, as soon as SoC drops to 39.9 the ICE kicks back on.

"When ICE cruising does the SoC hit 53% and more or less stay there?"
I RARELY drive far enough to get the SoC above 50%, most of our trips are very short. The couple times I have gone on longer drives above 40mph, the SoC gets to 53-55%. Doing some serious hills, I saw it get to 58 for a while. When I got home from a trip, the SoC read 28% after starting at the airport, it charged continuously on the trip home and got to 65% (never let me go into EV) like it was trying to do a Cal cycle or something, but I go home and shut it off. The next morning it operated more or less normal, starting around SoC = 36%

"Do you have to have SoC at ~ 42 to go EV? "
Seems like 42.3 or better and I can go EV

"How much does SoC drop when kicking on the ICE out of EV?"
usually .1%, every once in a while .2%

"The fact that you did get a wrench light makes me think that you do indeed have an electrical problem. Even though it would only be a 20W drain, having it for 10hrs with the car parked should be affecting your mileage noticeably."
I was thinking about using the service disconnect at night for a couple nights and seeing if the SOC still goes down or not - might give me a clue if it is something in the battery module or in the HV section elsewhere.

The thing is I am pretty sure the SOC isn't really getting that low, as I have seen some REALLY low numbers, but the FEH still starts every time. When I first turn on the key, the SG usually reports a SOC close to what it was when I turned it off, but as soon as I start the ICE, the number changes to a much lower number, the lowest I think I have seen yet is 9%

"If you have 30MPH roads that you can EV and then charge you can quite possibly hit 60MPG with straight gas and well into the 50's with E10 provided you are out for 10 miles or more and the temps are in the 60's."

Typically i am getting 35-38mpg for city driving if I am going 10 miles or more. My average tank is hanging right under 32, but we still have a lot of 2-5 mile trips starting from cold with the low SOC, and we do good to average much better than 24-26mpg on those trips.

Thank you for all the help troubleshooting. I talked to the service manager at the local ford shop, the tech who is hybrid "certified" was not available. The service manager said I could bring it in and they would scan it, but at this point I don't think they would find anything.

 

I just went out and double checked the SG codes again, and everything is as it should be, according to the information off the manufactures site.

"It should drop from the 50% to the 40%'s or from the 40%'s to the 30%'s.
It is very, very rare to get a 'normal' car lower than about 33%."