PHEV... HV mode then switching back to EV... doesn't always work.

[Nick72]

So I've noticed on a few occasions when I try to switch back to EV mode from HV the driver display shows EV has been selected but the engine is still definitely running. This stops and it reverts back to EV after a few tens of seconds. Only happened a few times but on one occassion despite it showing EV mode the ICE was running for about 7 or 8 minutes. Tried cycling between EV and HV but to no avail. Driver display followed my selections correctly but it was always the ICE running until I switched off and back on when the problem went away. Plenty of charge in the Battery. 

As I say this isn't very often. Quite rare but it is happening. 

Any ideas? Could be idiot operator syndrome. 

 

Best part of 500 mile round trip coming up so I'll find out more on that.

[ernieb]

Yep seen that also, I've assumed it's running the engine to use some fuel from the lines and possibly warm the ICE. I've looked at the power flow monitor and it is sometimes running but in an ideal mode.  I've got to the point that I don't see it as a problem just part of the clever Toyota management system, ICE is running, I've started so I'll finish.

Have a good trip.

[ernieb]

Interesting this morning I was out fairly early and used the key to preheat the cabin not tethered. When I got in the car it fogged up so I put on the windscreen de mister (non electric) and the rear de mister (electric) and immediately the ICE kicked in even though I’d got a full traction Battery.  So another situation that I’d assumed would just be using electric but fired the ICE.

[nlee]

10 hours ago, Nick72 said:

So I've noticed on a few occasions when I try to switch back to EV mode from HV the driver display shows EV has been selected but the engine is still definitely running. This stops and it reverts back to EV after a few tens of seconds. Only happened a few times but on one occassion despite it showing EV mode the ICE was running for about 7 or 8 minutes. Tried cycling between EV and HV but to no avail. Driver display followed my selections correctly but it was always the ICE running until I switched off and back on when the problem went away. Plenty of charge in the battery. 

As I say this isn't very often. Quite rare but it is happening. 

Any ideas? Could be idiot operator syndrome. 

 

Best part of 500 mile round trip coming up so I'll find out more on that.

I think I experienced that once. From memory, I think I had gone from sole EV to HV briefly and back (still a novelty and just playing). I assumed it was once the ICE started it continued to warm up. It was about 1-2 minutes.

[Nick72]

9 hours ago, ernieb said:

Interesting this morning I was out fairly early and used the key to preheat the cabin not tethered. When I got in the car it fogged up so I put on the windscreen de mister (non electric) and the rear de mister (electric) and immediately the ICE kicked in even though I’d got a full traction battery.  So another situation that I’d assumed would just be using electric but fired the ICE.

Same. Had that too.

Yeh not a problem. Just wanted to establish if it was normal which by the sounds of it, it is.

Just done several hundred miles today. I almost managed to get the blue reserved Battery part to zero. A midge over. Suspect several more hard up hill accelerations at 70mph would have used it all. That could have been interesting. Assume it then drops back to 170hp for a brief time.

[ernieb]

14 minutes ago, Nick72 said:

Same. Had that too.

Yeh not a problem. Just wanted to establish if it was normal which by the sounds of it, it is.

Just done several hundred miles today. I almost managed to get the blue reserved battery part to zero. A midge over. Suspect several more hard up hill accelerations at 70mph would have used it all. That could have been interesting. Assume it then drops back to 170hp for a brief time.

No that's not my understanding it retains it's spec'd performance because it reserves the 30% traction Battery to maintain the acceleration etc. Once at speed the ICE maintains the speed. 

[Gray86]

Maybe regenerating the exhaust particulate filter 

[AJones]

Have a look at the full electronic manual for the vehicle, it is longer than the typical paper manuals supplier with the vehicle, I expect it covers it.

The Prius PHEV runs the engine when using the front defogger, I assume it's because it needs both the air-conditioning to cool and condense the moisture out of the air, followed by heat from the engine heat-exchanger to warm it back up again. If you don't want the engine to run, rather than running the front defogger, try setting the blower on warm and to blow at the windscreen, this just runs the AC as a heat pump, so without the engine needed.

It also has a behaviour where once you've started the engine, it goes through a full warming cycle before it will shut off.

[Nick72]

13 hours ago, ernieb said:

No that's not my understanding it retains it's spec'd performance because it reserves the 30% traction battery to maintain the acceleration etc. Once at speed the ICE maintains the speed. 

Yes, the reserve was almost gone though. If I had push a few more hard accelerations up hill on the motorway in the south west there would have been no hard accelerations left since the traction Battery hp would have been used up completely. So, maintaining speed for sure from the ICE and charging up the reserve again. Was pushing the car hard. It has to have a limit. I almost found it. Needle was a smidge above 0.

[Nick72]

12 hours ago, AJones said:

Have a look at the full electronic manual for the vehicle, it is longer than the typical paper manuals supplier with the vehicle, I expect it covers it.

The Prius PHEV runs the engine when using the front defogger, I assume it's because it needs both the air-conditioning to cool and condense the moisture out of the air, followed by heat from the engine heat-exchanger to warm it back up again. If you don't want the engine to run, rather than running the front defogger, try setting the blower on warm and to blow at the windscreen, this just runs the AC as a heat pump, so without the engine needed.

It also has a behaviour where once you've started the engine, it goes through a full warming cycle before it will shut off.

Thanks. I think the latter was the case. Once started it takes time to **** off again. Not an issue but curiosity as to what might be happening and why.

[nlee]

1 hour ago, Nick72 said:

Yes, the reserve was almost gone though. If I had push a few more hard accelerations up hill on the motorway in the south west there would have been no hard accelerations left since the traction battery hp would have been used up completely. So, maintaining speed for sure from the ICE and charging up the reserve again. Was pushing the car hard. It has to have a limit. I almost found it. Needle was a smidge above 0.

I'm not sure I fully understand what you are saying but mine will only go as low as the blue/green interface on the dash dial (or 30% on the app). After that I can't force the car to use EV only mode so I'm not sure how I'd use the Battery other than the normal HV operation, which would only use the engine under fairly heavy load. I have thought you would really need to thrash it a peak output (around 300bhp) using ICE plus Battery for a sustained period without any regen to exhaust the Battery.

If you did deplete the battery completely I guess your assumption would be correct, it could only run at the max output of the ICE only and you would have no power to the rear wheels (as I think they are only battery driven). Probably not a good situation to get into and not too healthy for the battery i'd guess.

[philip42h]

Yes, but that's how the HEV works all the time! I suspect the term 'reserved' is a bit confusing - I think what you mean is reserved for HEV operation - because if you could really force the car to run as an EV until the traction Battery was truly flat you'd be a bit stuck.

As an HEV the car will use the electric motors for acceleration and re-charge the Battery as much as it can on overrun and through braking. Once the level in the Battery gets lower, it will run the ICE to self-charge the battery. But as Nick implies, if you were to accelerate hard up an infinitely long incline you must eventually get to a point where the car will no longer draw power from the battery and you are down to ICE power only. (It really must reserve just enough battery power to be able to restart the engine ... )

Practically, of course, it will harvest energy as it goes and at least try to keep a decent level in the traction battery via self-charging in case it is needed ...

[ernieb]

I’ve just tested this having depleted the traction Battery so that it’s in the blue section and running in HEV mode.    Very steep hill (Derbyshire) and gave it some beans whilst monitoring the power transfer on the info screen, power delivered from both the traction Battery and the ICE. On some sections when I lifted slightly the power was delivered only from the ICE and it tried to recover energy but hit the accelerator again and the dual power mode was resumed. It worked as I’d assumed it would, I’ve never been anywhere near draining the traction Battery or getting near the “0” and I’m sure that the system would not allow that to happen.

[philip42h]

... and I rather assume, just like the fuel tank, when the car says it is empty it isn't telling the whole truth and has just a little more in 'reserve'. And, just as with the fuel situation, we don't really want to find out exactly how much that is  ... 😉 

[ernieb]

Philip, I never want to run out of fuel and so far never have! I figure that the reserve in this car is a lot healthier than others I’ve owned. Some of the US forums I’ve read in the past suggest around 2+ US gallons?

[philip42h]

48 minutes ago, ernieb said:

Philip, I never want to run out of fuel and so far never have! I figure that the reserve in this car is a lot healthier than others I’ve owned. Some of the US forums I’ve read in the past suggest around 2+ US gallons?

That seems about right ... with previous diesel RAVs, with 60L tanks, the most I ever got in was 51L - suggesting around a 10L reserve. The most I've ever put in this one with a 55L tank is 48L so around 7 or 8L in reserve (I was right down to "zero miles remaining" and then the next filling station). 2 US gallons would be 7.5L so that is fully in agreement with my experience ...

Of course, once you get down to using the 'reserve' you have no idea how much is then left!

[ernieb]

Philip, the good thing is that at around 2 gallons with these cars you can expect to be able to drive to a fuel station to get a fill up, assuming that is that they actually have got fuel. Seriously, it is a good reserve to have but I wonder if I ran out of fuel would the car let me deplete the traction Battery? I somehow doubt it would allow it to run to zero but it might get close.  What we need is a volunteer to give it a try, but not a game I would want to play. 

[Sealiedog]

Having been in an Outlander forum for some years, I've read about people driving up mountains in the Alps, sometimes even towing caravans. I'd guess the software in the RAV4 is similar. The Outlander reserves 20-30‰ Battery too which it draws on when more power is required. It then replaces the charge as quickly as possible regardless of what settings you use. You could push it into a kind of turtle mode, but most people will never see it. I'd think the RAV4 is similar. With 30‰ in reserve you'd probably have keep your foot to the floor for a few miles to use that up and that seems unlikely for most people. 

[Nick72]

13 hours ago, nlee said:

I'm not sure I fully understand what you are saying but mine will only go as low as the blue/green interface on the dash dial (or 30% on the app). After that I can't force the car to use EV only mode so I'm not sure how I'd use the battery other than the normal HV operation, which would only use the engine under fairly heavy load. I have thought you would really need to thrash it a peak output (around 300bhp) using ICE plus battery for a sustained period without any regen to exhaust the battery.

If you did deplete the battery completely I guess your assumption would be correct, it could only run at the max output of the ICE only and you would have no power to the rear wheels (as I think they are only battery driven). Probably not a good situation to get into and not too healthy for the battery i'd guess.

First time I saw this was on the motorway going, well, fast, and accelerating hard up hill. You can literally watch the needle fall towards zero after doing this a few times. Pretty sure i could have got it to zero but that would have been an unnecessary risk.

[Nick72]

13 hours ago, philip42h said:

Yes, but that's how the HEV works all the time! I suspect the term 'reserved' is a bit confusing - I think what you mean is reserved for HEV operation - because if you could really force the car to run as an EV until the traction battery was truly flat you'd be a bit stuck.

As an HEV the car will use the electric motors for acceleration and re-charge the battery as much as it can on overrun and through braking. Once the level in the battery gets lower, it will run the ICE to self-charge the battery. But as Nick implies, if you were to accelerate hard up an infinitely long incline you must eventually get to a point where the car will no longer draw power from the battery and you are down to ICE power only. (It really must reserve just enough battery power to be able to restart the engine ... )

Practically, of course, it will harvest energy as it goes and at least try to keep a decent level in the traction battery via self-charging in case it is needed ...

Exactly.

Now most normal driving conditions will never deplete this reserve so both ICE and Battery power is available to deliver the 302hp. But, 75mph plus on an incline and a few hard foot down accelerations back to back will get you towards zero. As I just discovered on my outbound and inbound mega road trip. Just got back.

[Nick72]

11 hours ago, ernieb said:

I’ve just tested this having depleted the traction battery so that it’s in the blue section and running in HEV mode.    Very steep hill (Derbyshire) and gave it some beans whilst monitoring the power transfer on the info screen, power delivered from both the traction battery and the ICE. On some sections when I lifted slightly the power was delivered only from the ICE and it tried to recover energy but hit the accelerator again and the dual power mode was resumed. It worked as I’d assumed it would, I’ve never been anywhere near draining the traction battery or getting near the “0” and I’m sure that the system would not allow that to happen.

Got to have a high drag. Steep hill alone won't do it. 75mph+ plus steep hill plus back to back hard acceleration and you can see the needle fall towards zero.

[ernieb]

7 hours ago, Nick72 said:

Got to have a high drag. Steep hill alone won't do it. 75mph+ plus steep hill plus back to back hard acceleration and you can see the needle fall towards zero.

Wow, you must have been pushing the envelope, maybe you should join the Toyota ‘test to death’ team? 😊

[Nick72]

12 hours ago, ernieb said:

Wow, you must have been pushing the envelope, maybe you should join the Toyota ‘test to death’ team? 😊

Have done way over 600 miles now so figured it was time to see what it could do. It is totally immense. Safe driving at all times of course. I've driven a lot of vehicles including tanks and flown aircraft so I think I know what I'm doing and what others might do.

Think I read somewhere that in the mid speed range it is faster than the Supra. I do actually believe it. Still managed 48.7 mpg! How do they do it.

Sleeper car.

 

[ernieb]

Nick, the thing is the RAV PHEV just does not look like it has the performance it can produce when needed and yet feels very planted.

[philip42h]

It must be time to post the moose test video again ... 😁

😉