Long trip speed issue..

Hi Kyle,

I don't think this is normal. A few thoughts:

1. Did you replace the engine air filter at the 60K mile service?
2. If yes, you might check to see if there's anything blocking the engine air intake.
3. If the battery was at one bar, then the powertrain won't be able to deliver much power as MG2 won't be able to provide much help to the gasoline engine.

 

This was a few months ago? What has happened since?

It may be that your higher speed driving/climbing was pulling more power than the ICE could muster and eventually pulled the battery down to the point that the ICE was the only remaining power source. You can get the battery back up any time just by putting it in neutral, I think. That should cause the ICE to run and recharge the battery.

 

Actually, shifting into N will prevent the traction battery from being recharged, as the MGs are electrically disconnected.

If you desire to recharge the traction battery, one way to do that is to shift into D, hold the car stationary by depressing the brake pedal hard with your left foot, then floor the accelerator pedal with your right foot. Since the car is not moving, power from the gasoline engine will flow into MG1 which will quickly charge the traction battery.

However this procedure is not recommended by Toyota, so use at your own risk.

 

+1 on Patrick Wong's comments.

If you had ben driving continuously at "hour 16," perhaps you weren't
thinking really clearly at that point... driving on internal auto-pilot...
done that on many an occasion...

I would suspect an unfortunate, but anticipatable, conjunction of
conditions that resulted in the car operating at the edge of it's
performance envelope, including but not limited to:
* relatively high altitude
* probability of frontal or cross winds
* High speeds

I would guess that the little 1.5L four-banger was working really hard
to provide the power called for by the HSD to met the "go-pedal"
requests. HSD threw in some HV battery power to make up the
difference... and as virtually all the ICE power was being use to move
the car, little or none was diverted through the PSD to MG1 to
generate power to put back into the HV battery.

The only thing in the three variables under the driver's direct cotrol is
the speed. Reducing speed by just 5 MPH can make a huge difference
in the power needed. As speed increases, the retarding forces created
by aerodynamic forces on the car grow as a square function. The real
problem is that the power needed to overcome the those forces goes
up as a cube function. At high speeds, small velocity increases require
huge power increases.

* A doubling of speed creates four (2x2) times the retarding force on
the car.
* That same doubling of speed requires that the ICE/HV battery
provide eight times (2x2x2) the power.

The Prius is a super little car. That said, it is not a LITTLE SUPER CAR,
the normal conditions and limitations of aerodynamics, physics, mechanics,
etc. still apply.

 

That's a great quote!

 

Wyoming has the same effect on me - puts me right to sleep as soon as I cross over from Colorado

I have driven the Colorado mountains (7,000-8,000 ft altitude) and although the battery depleated, and the poor little ICE was roaring its little heart out, it hauled me, the wife and two grown kids at highway speeds (if it had a tongue, it would have been hanging out when we got home). the mileage was no better than a conventional FWD, and the power was worse - obviously the Prius isn't built for this, but it took it and did its best. I've never seen 15 mph up ANY hill - I've never seen less than 55, probably, even in the Colorado mountains.

 

It is hard to recognize the steep climb as you were going over the continental divide, I once pulled a mobile home with a fire dome v/8 desoto and stopped and examined the tires, motor and everything else . When I got back in tha motar really lugged getting rolling again. I stopped for gas and spoke to an attendant and he knew the problem ,as every one experiences this . The land scape is so flat that you cannot see the upgrade which is quite steep

 

Too bad you didn't have a Scangauge set up monitor battery and inverter temperatures. Is there any chance they were getting hot and going into a protective lower-power mode?