Will Prime drive even if lithium battery is dead?

The car won't let the batteries go completely dead like an EV does. The car treats the Prime battery as a separate level on top of the standard Prius battery. Short of an actual malfunction the car will turn into a slightly heavier regular Prius after 20-30 miles.

 

Nope. The HV battery crank starts the gasoline engine.

Now OTOH, it's possible that it may drive fine in EV only mode till the battery is drained if, say, the gas engine had an issue like if it's out of gas. People have done that in emergency situations even in non-plug-in hybrids. TIP: don't attempt this unless it truly is a dangerous situation as the battery can really be damaged if discharged too low.

 

No. The engine won't "crank over" without some charge in the "traction battery" (the lithium one). Even if you could somehow start the engine the car wouldn't move until there was some charge in the battery. BTW, I don't think you could start the engine, as you can't "push start" it - the system won't transmit power without the MGs energized (by the traction battery).

AND, a "regular" Prius Hybrid (normally called the "hatchback") also can't run without the traction battery for the same reasons.

A completely dead traction battery means you are going nowhere, fast or slow.

And finally, the HSD will -always- leave some charge in the traction battery, both for the plug-in and the hatchback. The minimum it allows it to be discharged to is about 20-30% (depending on circumstances), so it can always start the engine.

 

Even the regular Prius hybrid won't run if the hybrid battery is completely dead. The car newer let's you to completely drain the battery

Normally batteries don't just die, but the degradate to the point when one of the cells fails, this degradation is slow and it can take years nad you will definitly notice it, before it completely fails.

 

Correct but there are two battery ranges. The upper range allows EV operation. When that is used up, the second range comes into effect, the hybrid mode range. The car automatically runs the engine as needed to sustain a safe range.

Before that happens, a 'power steering fault' shows up and the car becomes a rolling mass. There is enough charge to start the car but a 'latch' is set in the control software that prevents starting. So you put some gas in the tank and do a 12V, power-on, reset by disconnecting the battery ground for ~10 seconds and reconnecting. The car engine will start and you have whatever gas put in to reach a gas station or charger.

Yes and no by setting the mode switch to HV. No because the improved control laws give better mileage than our old Gen-1 and Gen-3 Prius. You'll have to put up with burning less gas.

Bob Wilson

 

This is not completely true. If out of gas, the HV battery will try to crank start the ICE at a continuous RPM that sounds like it's running and will do this even if it drops below the minimum threshold. Folks who've run out of gas AND continued to drive on EV till the car no longer moves have bricked the car because the battery was forced below the minimum SOC.

 

Just editorial: you're right, a lot of people refer to the regular Prius as "hatchback", but it seems a misnomer: they're all hatchbacks. But yeah, Toyota created the naming shortcomings, so we cobble.

None of the Prius family can do that: when the battery's critically depleted, it's time to tow to the dealership. With a brand new Prime though, worrying about such matters is cargo cult.

 

no, but you won't have to worry about that for at least 10/150.

 

I thought Hatchback was used to differentiate among Prius C, Prius V, Prius Prime and Prius Hatchback. So to me, there is a usefulness to the term Hatchback...

 

i thought we were using lift back, pip and prime.

 

Neither the Prius nor the Prime can operate if the High Voltage Battery is dead.
The engine is started by the HV Battery, via Motor/Generator1.
The engine never pushes the wheels directly, it opposes the M/Gs. All N is in a Prius or Prime, is not allowing electricity to flow to the M/Gs.
Your HV battery is warrantied at least 8 years or 100,000 miles in the US.

 

One of the few downsides to a power-split hybrid like the Prius is that can't operate as just an ICE car.

 

fotomoto opined:
"This is not completely true. If out of gas, the HV battery will try to crank start the ICE at a continuous RPM that sounds like it's running and will do this even if it drops below the minimum threshold. Folks who've run out of gas AND continued to drive on EV till the car no longer moves have bricked the car because the battery was forced below the minimum SOC."

I've heard of some worrying about this Doug, but I've never seen anyone post that it happened to them. My understanding is the car will attempt to start an "out of gas" car until the battery is -almost- empty, then give up until it sees gas being put in the tank. Hence my "20% to 30%" comment. 30% is normal operation. Running out of gas would then take it down to the 20%, but maybe lower.
Either way, people have to realize even a plugin Prius runs on gasoline in the end. Keep some in the tank at all times.

 

This is what happened to me when I did the forbidden experiment:
[WARNING] Running out of gas | PriusChat

Bob Wilson

 

I was going to say I hear liftback used more often. Liftback is a better description also.

Yes but only when using the term liftback. Liftback is a type of hatchback, the term is used where the hatch is more horizontal than vertical. Prius c and Prius v are hatchbacks, Prius is a liftback. Yes the Prius is a hatchback also but of the three it's the only one that can be referred to as a liftback, and so that became its nickname.

Then Prime came along, and yes it's also a liftback. But hey, it's the Prime, and so that's what we call it, and continue to refer to Prius as the liftback. And the PIP will forever be the PIP.

Now in case you are wondering why I used lowercase letters for Prius v and Prius c, well that's another convoluted Toyota story for another day.

Yes but dead being a relative term.

"As Coroner I must aver, I thoroughly examined her.
And she's not only merely dead, she's really most sincerely dead."

It takes very little power to crank ICE, if the battery is "merely" dead (charge is extremely low) then in some cases the software will allow the engine to start but it will refuse to use the traction battery for propulsion in order to protect the battery. The car will be extremely underpowered, with almost no torque, but still driveable, at least driveable enough to make it to a dealer if it's not too far away, or at least a safe place to park.

But yes if the battery is "most sincerely" dead then you aren't going anywhere.

 

[DO NOT TRY THIS AT HOME]

I ran completely out of gas in my Gen 2 in only 8 miles after it started blinking, as I had driven 30 miles while blinking before and much cheaper gas was 10 miles away.

I could see the expensive station, so I drove slowly on battery. And pushed the last 15 feet. Once I had a fill up, the car was still extremely sluggish for about 5 miles.

 

Been there done that. In my Gen 2 I have often gone 25 miles after the fuel warning, and based on how much gas it took to fill I calculated that I probably could have gone at least another 15 miles, although I never experimented to find out. Except once. I was so close to 575 miles that I just couldn't resist, and I kept going until I hit 575 exactly then pulled into the nearest gas station (they were all around so even if I had run out I wouldn't have had to walk far). That was 53 miles after getting the fuel warning. It took 11.4 gallons to fill the 11.9 gallon. Of course with the Gen 2 bladder you never can fill it completely, so most likely I was extremely close to running out of gas and I never tried that again and stuck to 25 as my absolute maximum.

Then one time the engine quit just one mile after the fuel warning. So I don't mess with it anymore and I don't go below 1/4 tank no matter how many gas stations are around.