Traction battery life

Yes.

The Traction battery is not required to start the ICE.

The ICE starts with its own 12vdc battery.

Yes.

 

I disagree , MG 1 starts the ICE and it is powered by Traction battery.,the 12Vdc powers mainly the computers systems that enables the traction battery to power the car.

 

Fwiw, that's all incorrect.

The gas engine is started by MG1. MG1 is powered by the traction battery.
The 12V battery is there for the electronics and standard automotive battery powered devices (all of the computers, windows, dash, lights, radio, etc).

The Prius is not some worthless moronic cheap *stupid* flaming pile of cr**p Hyundai.

Code:

https://www.youtube.com/watch?v=6ZDEfFXMiAs
Toyota Vs Hyundai Hybrid | Is Toyota Still The King of Hybrids?
The Car Care Nut
Nov 9, 2022

Also, Weber Auto has a lot of very good, semi in depth videos on the Prius/Rav4, etc hybrids.
And, check out: https://slideplayer.com/slide/13079326/

 

When my 12vdc battery is dead the ICE will not start.

The 12vdc battery powers the starter motor.

 

When the 12V battery is dead , the computers are out of service thus no connections are made to engage the traction battery,
there is no starter motor.

 

Correct.
All of the computers run off the similar chips/components as a "regular car".
Most components run off of 12v, 5v, 3.3v, 2.5v, 1.8v, 1.5v, 1.2v, and so on.
Imho, 5v, 2.5v, and 1.2v all make "sense". Humans often use 5 and 10.
The 3.3v standard was chosen because it allowed for easy interfacing to the"original" 5v digital "TTL" devices.
There are reasons for each voltage standard.

There are a number of reasons why the voltage standards for chip has gone down. Mainly it's power and heat.

Power is proportional to Voltage Squared (V²).
Power is equal to the Voltage**Squared divided-by Resistance
P = V²/R

For electronic circuits today, heat and power are major concerns now.
Today, a typical processor will have millions to billions of "transistors".
Every time a transistor changes state, it takes power, and generates heat. 1GHz means switching a billion times a second.
So, when you have a billion transistors switching a billion times a second, and each switching transistor takes power, that results in a lot of power and heat.
Hence, why the chip voltages have dropped over the years. For various reasons, ~~1.2v is near the limit to easily make "digital" circuits (true/false - on/off).

The 12v standard is commonly used for motors - power windows, windshield wipers, locks, seats, transmission "park pawl", and so on.

 

Based on what I have learned over the years coming to PC and reading information on the Prius and PP.

NO, if the traction battery is "dead" as in non-functional.

I would think as long as the capacity of the traction battery is enough to operate on HV mode which is about 14% of the total SOC of the original capacity, the car should run... But PP may have a built-in sensor to warn if the fully charged battery capacity falls below a certain level.

No, I don't think so. If comparing the same chemistry batteries.

No.

 

Fwiw, because of the way that the Prius tranny works, even if some Space Alien, using magically powers they stole from a Smurf, started up the gas-engine, it would be worthless (if the hybrid battery was dead).

***************
If the hybrid battery was fully discharged, a (magically started) running gas engine would not be able to charge the hybrid battery.
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No hybrid battery in a Prius, then push it over the edge of the earth.

Again, Weber Auto has a lot of great information on how the Gen4 Prius system works.

 

The power-split system in a Prius needs the battery to run. The motors don't just make the car move. One of them works with the engine to make the transmission work. Without it, the engine will just free spin the gears.

Just going to add that if the battery reaches the point where its capacity isn't enough for meaningful EV range, and just run the car as a hybrid, it will likely totally fail in the near future.

 

While I have never had the traction battery fail on my Prius (Gen3) or PP, I had the traction battery of the 2008 HCH (Honda Civic Hybrid) fail once. With Honda's old IMA design, the car can run on an engine alone with a dead hybrid battery. The mileage plummeted to 15-20mpg from the usual 40mpg, but the car did run for a while with just the engine alone until the traction battery was replaced for free by a Honda warranty at 110kmiles on the odometer. I don't know how the newer Honda hybrid system is like the in the Accord or the new CRV. But my son is driving an IMA hybrid CRZ. While I don't think it will have problems like the early Civic Hybrid did, if it does fail, at least he can still drive the car.

 

IMA was a mild hybrid system. It gave some help to what is still an ICE car in design.

Honda's system in the Insight3/new Civic, Accord, and CR-V is a power split like in the Prius. Going to need the battery to function.

Not sure about full strength parallel systems. With a typical automatic transmission, the motor is between it and the engine. Maybe the engine can drive the car without the traction battery. For the ones with a DCT, likely need the battery. The motor in those typically drives the odd gears, and the engine the even. With just the engine, you'd only be using 2nd,4th, and 6th gears.

 

I imagine you'll run into other problems before the traction battery is completely dead. What killed my 2006 Camry hybrid at 200k+ miles wasn't the battery but the wife ignoring a coolant leak to the hybrid system for a full day and 100+ miles when with it 90 degrees out in Texas. It went into a limp mode long enough for her to pull into a dealership and put a deposit down on a new Tundra.

Seals rot, hoses spring leaks, wires corrode. Any modern car is just as likely to meet an electrical or computer repair that costs more than it's worth as it would a mechanical failure of a major component.

And even the older prius generations had battery failures that didn't totally strand you. Think of it as having an alternator wear out vs the engine throwing a rod. A complete traction battery failure probably won't happen. A module may crap out or a component along the way might overheat.

 

I see you live in Canada. How is the road salt in your country? In my region, no car will last longer than 15 years due to rust-related issues. Doesn't matter how good the engine or (in the case of BEV or PHEV the battery) is. In fact, I usually start spending $$$ for repairs and services directly caused by rust by 8 years old. I can not see any car lasting 20 years on the road in our region unless the car is detailed at the end of the fall season and garaged for the entire winter period every year.

I would not worry about the battery failing on any of the electrified vehicles no more than other issues that crop up at high age or miles. FYI, I think the reference to the 250,000 miles is probably based on the average 15K miles/year. So, it is more like 17 years. For the hybrid battery, unlike the engine, the years of age is a more important parameter than the miles driven to determine the end of life.

 

Toyota provides the answer to OP's question. In any case, don't use the BEV mode for excessive speeds, and avoid fast acceleration and deceleration. Don't use Prius Prime exclusively as a BEV. You should not put more than ~ 75,000 miles in the BEV mode, which will probably near the battery to the end of its life. And, no, no Prius can run without the HEV/PHEV battery.

Enhanced Prius Prime Hybrid Battery Warranty

We have expanded our hybrid battery warranty to reflect our confidence in the quality, dependability, and reliability of our products. From the 2020 model year forward, every Toyota hybrid battery warranty will cover 10 years from date of first use or 150,000 miles, whichever comes first (previously 8 years or 100,000 miles).

For Toyota hybrid vehicles beginning with model year 2020, the hybrid (HV) battery is covered for 10 years from original date of first use or 150,000 miles, whichever comes first. Coverage is subject to the terms and conditions of your New Vehicle Limited Warranty. See Owner's Warranty and Maintenance Guide for details.

https://www.toyota.com/priusprime/features/mpg_other_price/1235/1237/1239

 

75,000 miles would be something like 3000 full charges and driving all 25 EPA miles each time.

At 2 hours per recharge we're talking 6,000 hours or 250 full days connected to an EVSE. Just because I'm dumb as rocks and not good at math let's assume you average 50 miles an hour for all those miles so you're "only" spending 1,500 hours butt in seat driving.

I don't know if I'm a typical use case but I have about a 100 mile commute round trip and I only drive the first 25 miles in EV (in winter it's more like 15 because I gotta go up about 1000' in elevation to work...but again, i'm dumb and that's too much math for me) and I rarely get to charge at work. So only 1/4 of my driving is in EV. To reach 75,000 EV miles it would take me 300,000 miles and probably 10 years at my current 30,000 miles a year after weekend trips and road trips are accounted for.

 

the thing is, a small number of batteries fail after the warranty is up. iff you are one of the unfortunate ones, the prime would cost a lot more than the regular prius simply due to size.
if you plan on keeping it 20 years, you have to reckon with a number of potentially expensive repairs.