Idle Charge

[mss]

I have a question/ comment regarding the feedback and operation of the Prius.

One state of the vehicle on the MFD is:

ICE -> Electric Motor -> Battery

This occurs when you first start the car and are still in park when the ICE kicks in. Yesterday I was stuck in some parking lot congestion, the ICE comes on and there is no indicated flow of energy (I am in Drive, but stopped). So as a test, I put it in park (I wasn't moving anyway). Then I see the energy flow go from the ICE to the Battery. I Switch to drive, no energy flow.

My Question is: When the engine is on and in idle - does it charge the battery even though there is no indication on the MFD? Another example of when this could occur is when I coast or use the brakes down a hill after just having started up the car. The ICE is on, but I have green arrows going from the wheels. I never see energy flow from the engine only to the battery when it is on in an idle state and am engaged in drive. If I tap on the accelerator, it will immeditely show energy flowing to the wheels and the battery.

I also wish there was an indicator on the MFD to show when the engine is on.

Thanks.

[olends]

there are times when the engine is running and no charge is being generated. one i can think of is, engine not at temperature, charge at normal. in that case the engine is running to gain temperature not to charge the pack.

also the engine will spin without fuel. to reduce charge in the battery pack if the car senses overcharge.

[DanMan32]

Sometimes the MFD oversimplifies and therefore misleads. ICE will run at stop if BSOC is below 2 bars, or if temp is low. Low temp warmup run is usually reserved/delayed until the car actually moves though, even if it is a creep.

[olends]

is it possible the the break is not fully depressed. so the MFD is trying to show the electric creep, and the battery charging at the same time?

[DanMan32]

OK, did the experiment, as I needed to go to the bank which unfortunately was JUST outside of the battery range.

Coming back to work, ICE started almost immediately instead of the 7 second delay, probably because EV was not valid; charge too low.

I waited a bit too long to check, so I may have invalidated the test, but I did observe what MSS was observing. When I got to my work parking space, I was no longer in red, but engine was running at low idle, and appeared to not be charging. Placed in park, idle went up for a few seconds and did display charging.

Granted, my ICE was barely warmed up, but there was a distinct idle level difference when MFD showed charging (higher idle) versus no energy flow on MFD (lower idle).
I suppose it will take Attila's system to really know for sure. He can monitor charge current to/from the battery as well as ICE RPM and temperature.

[Frank Hudon]

BSOC below 57%, temp above 70C, ICE starts running will give battery a slight charge 3 1/2 - 5 amps. This can happen when you pull off the steet after a substantial trip and sit there and read the paper for a few minutes, the cat cools quicker than the ICE. This happens almost daily as I come off the hiway, stop at the store, buy the paper then have about 3/4 mile in stealth mode, pull into the parking lot and back into stall. BSOC is now down to about 60% and 5 minutes will pull it down to 57% and the ICE will run to bring it up. If I look at the O2 temps it's down. When I say O2 temps it's the output in mv from the sensor. Voltage up temp up Voltage down temp down. I leave it on to charge the aux battery.