Is it ok to power off prius during forced low battery regen?

If you let it idle for 12 hours it will simply waste fuel, albeit no more than ≤0.5 gallons. Yes it will charge the battery, but it is safe to switch off the car and it will charge as required next time you use it. That assumes you are not going to leave it unused for more than a day or two.

Welcome to Prius Chat.

 

It's fine to shut down. The car ran the battery down, due to low-speed driving, and kicked on the engine. But yeah, that happens all the time.

We would park in the upper levels of a parking garage, and spiraling slowly up through the levels the car would invariably run electric-only, and due to the grade eat up the charge quite fast. Engine would without fail be running by the time we parked, no problem: shut down. Later when starting up, engine continues to run.

Look at it this way too: if it was so important to follow certain behaviors with the car, they would be breaking left and right.

 

IIRC 2bars on the battery indicator on the Gen2 and Gen3 was actually about 40% HV battery State of Charge as indicated on OBDII port devices like ScanGauge II. Not sure about Gen4 as yet, but I hope to be doing some tests soon and will post on it in the New Year.

So there is still plenty of spare charge left. Maximum bars on these earlier generations was 80% SOC, and I understand this type of aggressive battery management is needed to maximise its lifespan.

 

Because of my rural location, I rarely park with more than 2 bars. Why waste gasoline forcing the battery to charge when you can be driving at the same time. During my warm-up, the battery is regularly charging at 20 amps or so at the same time I driving down the road.

 

If you want the engine to run while climbing the ramps, consider switching to B mode at some point while the engine is running, either during or just before the climb. I believe B will override the ICE auto-shutoff.

At low speeds, if the ICE is initially off, B may not help trigger the ICE to turn on.

 

With it in B, is it charging the battery?

To answer the OP's question - just drive it, mine often has 2 bars when I park, sometimes the ICE is on, other times not. In SINGAPORE's heat, it's going to be an undetectable drop of charge over just 12 hrs.

 

It ought to charge just as well as D mode with ICE spinning. The main point of this maneuver is to prevent the normal D-mode ICE auto-stop. It is unrelated the real purpose of B.

Agreed on all this, the 2 bars ought not be an actual problem.

 

you can't hurt your prius, shut it down anytime, drive it like a regular car. pay no attention to the man behind the curtain.

 

I park my car up a high story carpark(lots of ramps which eats up battery) too, so I don't have the luxury of keeping battery levels high before switching off.

#4sgpriusdriver, Today at 4:20 PM

Perhaps when you're driving up these ramps to park you could use the engine more by being more aggressive with the accelerator pedal wherever possible. Not to cause a danger to yourself or others goes without saying!

 

That's what runs ours down too. Low speed and a grade. No matter.