Hybrid System or Traction Battery Failure - Japanese Import

You're totaly "right" on that! I've been to UK once and it took some time to adopt to driving on the left side. However, after a few days I enjoyed it a lot. Taking a roundabout was a whole lot easier for my eyesight!

Congratulations on solving this problem and sharing it here! Enjoy your PiP. Good to know that charging a totally depleted high-voltage traction battery using a wall charger does take place without any visual feedback.
Based on your expertise waking Prius from hybernation needs:

• Some fuel
• 12V battery charged or supported externally to power up on-board computers, lights, and accessories.
• Tractional battery has to have minimal charge to start HSD (i.e. to get "READY"). When the tractional battery is charged enough, HSD starts in EV mode. When charge is low, the ICE is started using MG1 powered by the remaining charge in tractional battery, right? That would explain why HSD wouldn't get READY in your case as tractional battery was too depleted to start ICE.

Am I getting this right? Now I am confused, how you managed to drive the car for the first few miles in the first place?!

 

OK, that's the US buttons; the EU model has EV CITY instead of PWR. But that's intended for driving in regulated low emission zones, which I would guess Pakistan hasn't got round to yet.

If you've solved your charging problems and had some experience now, the next question is at what speed the car fires up the internal combustion engine (ICE) even though you are in EV mode with range left? I can explain EV Boost after that!

 

If anxious, you can charge traction battery without the charging cable using regen braking:

1. Do some serious downhill driving in HV. Enough to build a mile or two of EV range.
2. When the displays start showing EV miles left, you will be able to change to EV mode manually (press EV/HV button once).
3. After a couple of seconds change back to HV (press the EV/HV button again). Changing from EV to HV manually seems to tell the computer to leave the approximate amount of current state-of-charge for later EV-only driving. Driving in manually engaged HV will not deplete the charge much further beyond the SOC at the time of engaging HV.
4. Repeat the procedure until you build up EV range desired.

Take note, that this procedure might affect your MPG, as it is probably less efficient to charge traction batery by regen, instead of using a charging cable.

 

Probably the SOC measurement is cached in computer memory. Before your computer measured actual SOC it was too late.

Besides: Please, drop the concept of EV and HV partitions of the traction battery. There is one battery only. With continuous SOC.
Instead, imagine the picture of the battery when SOC is represented with bars as zoomed in view of the last few % of battery.

 

There is no separate EV and HV partition of the traction battery; it's all one big battery. The control software produces the illusion of two batteries, depending on whether it is in HV or EV mode. You can be in HV mode with significant charge by pressing the EV/HV button, but when the state of charge gets low enough (about 23%), HV mode is forced. But it's all software.

The Prius Plug-in prototype did have a separate HV and EV battery, and sometimes people come across old web pages discussing this and get confused. But the production model got rid of this.

 

Then, you're 2-3 days away of experiencing that undescribable wonderful feeling only plug-in owners know when we plug in our cars.

 

Did you turn the fan on, with or without the a/c? If so, that is the reason the EV estimate came down, it just knocks off 10%. Good you got the mileage out of it though.

That sounds like the EU model is the only one with the reduced EV max speed, and I'm sure it is to keep the emissions at below 50g/km.

 

it's actually when you switch the fan on. you can observe it, then turn the fan off and watch it revert back.

 

Preferably while parked... I do worry how much of my time is NOT spent looking at the road!

 

agreed! yesterday, a bicycle was coming toward me on the other side of the road. an impatient driver decided to pass him on my side of the road just as i was approaching. i do believe if i hadn't been observing the situation and not swerved to the right, it would have been a head on. we're always a moment away from tragedy whilst driving.

 

I'm sure someone has developed a set of protocols for storing a car with a hybrid battery for long periods of time. It should be plugged in, at least periodically when in storage. Even in ideal conditions, a battery will eventually discharge itself, even without external current draw, due to internal factors. In less than ideal conditions, it can happen even faster. Based on what I know about rechargeable batteries, my biggest concern about not driving a hybrid for a period of time, would be allowing the battery to become too deeply-discharged to be recharged.