PHEV-ICE starting unexpectedly

[ernieb]

Yesterday I was out and used the EV for two trips on the return I needed a hard acceleration and the ICE kicked in, expected so all OK.  When I got home I had 8 miles of EV range. No overnight charge and this morning a I did a short trip to the supermarket and back on the return I had 5 mies range left no problem as I was under a mile from home. I slowly pulled up a traffic light and the ICE started. I had not done any of the things that I know will fire up the ICE and it had run yesterday so there was no need to circulate the fuel and oil in the ICE?

Now in the scheme of things this is of absolutely no consequence but it niggles me that I don't know what triggered the ICE to start, I thought I knew all the circumstances but there's at lease one I've not got knowledge of, any thoughts?

[Roger_N]

What was the temperature by you? I'm having to defrost the front screen. 

[ernieb]

Roger, it was 6oC and raining no need to defrost and it was the return trip. I know the ICE will start if I needed to defrost the front screen/heavy downhill braking/hard acceleration or if the ICE had not run in months but none of these apply. As I said it’s not an issue but a niggle, a mind worm 🪱, I’d just like to know?

 

[Lawnmowerman]

On a number of occasions (recently) when down to 2 miles EV, it has switched to ICE. Then, when on a level road with (very) light throttle it has been reluctant to return to EV. Only doing so after about 3 miles of running.

I don't think I'll ever fathom it entirely but curious to the controlling factors like you Ernie.

[Nick72]

I've had that Ernie. With say 3 or 4 miles left and it went to ICE. Suspecting mismatch between displayed range (a rolling average in any case) and actual range based on actual remaining Battery capacity.

[ernieb]

11 hours ago, Nick72 said:

I've had that Ernie. With say 3 or 4 miles left and it went to ICE. Suspecting mismatch between displayed range (a rolling average in any case) and actual range based on actual remaining battery capacity.

You might well be right but this was a solid 5 miles and the SOC meter also showed well into the EV operational zone. The MyT app showed the same when got home.

But as a couple of us seem to have experienced similar drive characteristics then it may well be just the car doing it's thing.

[Nick72]

9 hours ago, ernieb said:

You might well be right but this was a solid 5 miles and the SOC meter also showed well into the EV operational zone. The MyT app showed the same when got home.

But as a couple of us seem to have experienced similar drive characteristics then it may well be just the car doing it's thing.

Yeh it would be great if we just got a little extra info. A setting. Do you want the extra info or not, as an option.

ICE started because...

[ernieb]

37 minutes ago, Nick72 said:

Yeh it would be great if we just got a little extra info. A setting. Do you want the extra info or not, as an option.

ICE started because...

If it starts for the just the warm up cycle when in EV mode then I’d be interested to know what triggered the cycle.

[Lawnmowerman]

I paid particular attention when coming home tonight as it switched to ICE at 2 miles charge remaining again. However, even though it is clearly running on ICE and the miles remaining on fuel is counting down it still displays the mile/kwh on the MID.

I forced it to go from Auto HEV to EV on the display but it still ran on ICE and the EV symbol that illuminates above the l/h instrument cluster did not illuminate.

Eventually EV commenced and the ICE ceased and with about 20 yards to go to home the EV quota was exhausted and the (still warm) ICE re-engaged.

Whilst in its own little world it may be normal, it certainly has not exhibited this trend for the majority of the 6,500 mile plus that I have owned it.

Curious...........

[Bernard Foy]

I’m no expert on anything, and especially on modern machinery. But I do know that if any Battery (no matter what kind of battery) is continuously run flat it will shorten the normal useful life of that Battery. So I suspect that the ice cuts in to prevent the Battery being fully discharged, thus protecting the life of the battery.

[Lawnmowerman]

Just now, Bernard Foy said:

I’m no expert on anything, and especially on modern machinery. But I do know that if any battery (no matter what kind of battery) is continuously run flat it will shorten the normal useful life of that battery. So I suspect that the ice cuts in to prevent the battery being fully discharged, thus protecting the life of the battery.

Thanks Bernard, in most respects that is correct but Toyota design them to stop discharging around 30%. This reserve allows the batteries to drive the motor(s) when required for acceleration (and I don't think they exceed 90% capacity either for efficient Battery life Management).

[Bernard Foy]

2 minutes ago, Lawnmowerman said:

Thanks Bernard, in most respects that is correct but Toyota design them to stop discharging around 30%. This reserve allows the batteries to drive the motor(s) when required for acceleration (and I don't think they exceed 90% capacity either for efficient battery life Management).

On my Yaris although it’s a completely different charging system, my ice cuts in at around 50% discharge, and definitely well above the 30% area.

[Flatcoat]

4 minutes ago, Lawnmowerman said:

Thanks Bernard, in most respects that is correct but Toyota design them to stop discharging around 30%. This reserve allows the batteries to drive the motor(s) when required for acceleration (and I don't think they exceed 90% capacity either for efficient battery life Management).

That is correct. It is one of the features cheaper EV’s and hybrids often lack to reduce Battery size, cost and simplify software. The MG HS PHEV bring one. Comes from Toyota’s long experience of hybrids and Tesla adopt a similar approach to preserve Battery life too. However there is also an argument it is wasteful of resources too. 

[Flatcoat]

1 minute ago, Bernard Foy said:

On my Yaris although it’s a completely different charging system, my ice cuts in at around 50% discharge, and definitely well above the 30% area.

Your Yaris is not a PHEV….. 

[Lawnmowerman]

2 minutes ago, Bernard Foy said:

On my Yaris although it’s a completely different charging system, my ice cuts in at around 50% discharge, and definitely well above the 30% area.

Is yours plug in too?

[Bernard Foy]

1 minute ago, Bernard Foy said:

On my Yaris although it’s a completely different charging system, my ice cuts in at around 50% discharge, and definitely well above the 30% area.

Oh and I forgot to add William that I’ve never seen it go to 100% fully charged either.

[Bernard Foy]

1 minute ago, Flatcoat said:

Your Yaris is not a PHEV….. 

Yes that’s correct and I am aware of that, that’s why I stated “ it’s a completely different charging system”.

[Bernard Foy]

6 minutes ago, Lawnmowerman said:

Is yours plug in too?

No William all Yaris ‘s are hybrids. But a Battery is still a Battery and a charger is still a charger, although your car is a PHEV which has a different charging system. Batteries do not benefit from being fully charged or fully discharged.

[ernieb]

Toyota do not allow the Battery to to be fully charged or discharged especially on the PHEV type cars. As has been said the user can use the EV mode till it reaches 30% SOC and the car will then automatically switch to HEV mode. I only manually select the HEV mode if I'm wishing a few miles of home and don't want the ICE to be still warming when I have reached home. Although the SOC will show it's 100% reviews I've seen indicate that the Battery gets to about 95%.  Driving the car hard in HEV mode will significantly reduce the SOC towards zero but it never get there.  From the perspective of Battery efficiency, longevity I think that Toyota have got it covered pretty well.

8 hours ago, Lawnmowerman said:

I paid particular attention when coming home tonight as it switched to ICE at 2 miles charge remaining again. However, even though it is clearly running on ICE and the miles remaining on fuel is counting down it still displays the mile/kwh on the MID.

 

 

William, I've also noticed when I'm in EV mode and the ICE kicks in, acceleration, heavy braking etc., the car remains in EV mode and the displays reflect this I guess that tells us that the system is using the iCE not to power as in HEV mode but for a momentary need?

[Catlover]

From what you just said Ernie, is that the computer knows you coming to the end of EV and is warming the engine up ready for when EV does end. I assume you could be doing some higher mph when EV ends and it wouldn’t be good for a cold engine to fire up at those speeds. Of course the driver is trying to get home on EV when it is showing 4miles available and the nit home is 2 miles, but the computer doesn’t know that. Computers are clever but not that clever.

[ernieb]

It’s something within the cars systems for sure Joe that the driver is unable to see or influence. In my latest case I was in traffic coasting towards the traffic lights with nothing else really going on which is why I felt it was so strange. It’s still a great system and I guess someone in Japan has figured it needed to be on and that OK with me I’d just like to know the logic behind the ICE firing.

[Lawnmowerman]

I paid more attention tonight again by watching the energy monitor (graphics). When it was at 2 miles charge remaining and the ICE kicked in, the meter in the MID continued to show miles/kwh although the EV indicator had extinguished.

However, what I found interesting was that the energy monitor showed that the ICE AND the Battery were both being used to drive the front wheels. This was in lightly stressed motoring that with a fuller charge would never have invoked the ICE.

Who knows what little idiosyncrasies lie within their algorithms - I fear we shall never know.

Shades of Elon Musk who introduces software that deliberately ignores perfectly valid requests from the driver - if it ain't in the script you ain't getting it. What puzzles me is that after 6,700 miles it seems a new development.

🙂

[NTheZone]

What we probably need is a more deliberate attempt to monitor the vehicle in its various modes -- EV, Auto EV/HV, HV, Sport, and Trail, using an OBD2 monitor under the exact same conditions, both at start up and while driving conditions, routes & ambient temperatures, included. 

I was trying to set that up using a Veepeak BLE plug in with CarScanner on my iPhone.  These discussions continue to add to the various tests that will be required to infer anything more than just anecdotal.  I haven't been commuting to a regular workplace, but a daily commute might be a good start.

[ernieb]

I agree William, it does seem very much like something new and it's only happened in the last week or so.  Up till then in EV mode the car just used its allocated charge and then made the switch to ICE.  As you say we will never likely know unless as ben suggested above the OBD port is monitored.  It's interesting that others seem to be experiencing similar drive characteristics.

[Nick72]

So I think it is mismatch between displeyed rolling average range and actual remaining capacity, as mentioned. 

A way to understand if this could be the up to 5 miles displayed range is to understand the variance over time between the displayed rolling average at start up on full capacity and odometer readings. If this difference is circa 5 miles on any one occassion then that proves there can be up to a 5 mile mismatch thus ICE has to come on.