Stages of Hybrid Operation

I was going over Daniels Stages of Prius Operation in the Knowledge Base and something struck me so I am checking it out. This was posted some time ago and as I understand it is based on G1-2 Prius data. I personal messaged Daniel and he has no way of checking the values posted elsewhere the following is the message I sent him.
As you know I have the ScanGage and have been tracking, among other things coolant temp. I think in degrees C at the hospital but in degrees F for other things. 23 C just does not mean anything to me when I am deciding to pick up a coat to go out! I have had the ScanGage set to degrees F and about 157 appears to me to be the temp for Stage III. I am now switched to degrees C to check it out but a bit of math tells me that 69 C is 156.2 and at 152 I can not glide or go into golf cart and at 69.4 C 157 F I can usually. At 70 C or 158 I would change that to always. Now I do not know how the CAN bus or the ScanGage round off but I only see whole numbers on the gage. I suspect the magic number is 70.0 C or 158.0 is the temp for conversion to Stage III. Nice even number and feels better than 73 C unless the number has some odd significance to the Japanese, Toyota or someone else in engineering. Why choose such a odd number? As near as I can tell 40 C is spot on for the Stage II but that is much harder to figure out as the end point is more vague. Do you have any thoughts?
I have now checked in degrees C for one day and 70 C appears to be the number for the G3 (counting G1 as the Japan only model). What do others with CAN View, ScanGage or other monitors think about the 04 and > Prii? Is there difference between my car (stock no computer upgrades or TSBs except the Nav upgrade that does not involve a flash) and the 06 and other software versions?

 

Are the "stages" on the CAN Bus as such or are you going to infer from the behavior of the car?

 

From everything I can find I think that much of what we know about the Stages of Hybrid operation is based on: First the G1 Prius including the early Japanese Prius and much of it came from observers in Japan but not all. I really have trouble following the Yahoo threads so I am not sure that I have seen even half of what is there. Given what I have observed I would guess that it is not a simple algorithm that indicates the operation of the various stages. I think the suggestion that it is multifactorial is a good one. It would be hard to check with out written data from day to day. I think at times I can get stage IV at as low as 67 degrees C with out stopping but 70 is much more reproducible. Ambient temperature may be a factor as well as SOC. That may be what I am seeing when the car is clearly at a temperature where it should be in Stage IV, and I have stopped previously, but just can not get it to go into stealth or glide mode no matter what I do, what I earlier labeled glide prohibited mode (see this post : http://priuschat.com/Pulse-and-Glide-or-Not-t14124.html). I think we need to consider more variables the obvious and the possibility that the programming on the G2 is much more different that the G1s than we may have thought. The more I learn about this car the more fun it gets!! I love this car. Can’t wait to get my CAN View installed.

 

I installed the CAN-View and of course discovered the Engine Temp. All my comments are based on Coolant Temps, as that is what the ScanGage reads. It appears that Engine Temp is a degree or two colder, at least on short trips. This puts a new face on the issue of temp and stages as I can not tell from old posts if people working out details were reading engine temp or coolant temps. I would say that it is up to us to look at the old data and the parameters we can look at today and create our own model.
I am also coming to the conclusion that SOC is a factor in putting the car in stealth and glide mode. I noticed that not only is my engine cooling on short trips and gliding but the battery is discharging at ~2 amps or less (oops I mean kWt or less amps are less than 10 or so). The second explains my observation that my SOC runs on the low end when pushing the glide mode, and dead banding during acceleration. Makes sense, and I should have thought of it, the power for everything else has to come from somewhere, and this time of year I have the lights on a lot (if not always). I let myself get to focused and literal watching the energy screen. I would guess in the summer battery temp will come into play. I think I am going to back away from compleat dead banding and allow a bit of charging on acceleration. I will still try to avoid battery discharge. As I recall the marathon guys last August had to allow more charging during the night when using the lights.

 

I am now going to call into question the concept of "gliding" ( heresy I know. I have my burning at the stake scheduled for some Thursday at two o’clock). At rest the car is pulling 2-3 amps closer to -2 to -3 with the lights and stereo on. Moving I can get down to 3 from time to time but mostly I am at -5 to -10 amps closer to -8 when the MFD shows glide mode. I would agree switching back and fourth takes time but by feathering I can get close to the at rest amp draw but not always. Where is the power going? Turning off the lights and stereo does not change this. I am wondering if when the MG2 is providing very little power it shows nothing (i.e. now arrows to or from the battery) on the MFD energy display. As near as I can tell so far any degree of charging is showing a green arrow to the battery. Clearly the MFD display is simplifying the power transfer. I know even from the ScanGage that the display will not show the ICE to be on through the warm up. I am proposing that "gliding" represents for the most part a very slight degree of power to the wheels with the ICE off at below 41 mph.