Can 2010 run on gas alone when HV battery fails?

Based on the Gen 2 version, and what I know about the changes to the Gen 3 version, I believe that it will not run for an extended time (or really at all) without the HV battery. For one thing, after the car is "booted up" the HV battery supplies power to the DC to DC converter to run the 12V accessories and to recharge the 12V (auxillary) battery.

You do know that the HV battery has either an 8yr/100,000mi warranty (standard) or a 10yr/150,000mi warranty (Calif emission states) right? So, it isn't really a huge concern for most owners.

 

The gas engine won't start without the HV battery. When you press the start button the car only 'boots' like a computer. When the car needs the gas engine, the HV battery spins up one of the electric motors (MG1), which acts in place of a starter motor. MG1 spins the gas motor to about 1,000 rpm before gas and spark are applied.

 

The car is not going to work without a HV battery, but the primary effect of aging on the battery will be to reduce its overall capacity, not to kill it outright (it's not like a lead-acid battery where bits of lead crumble off the electrodes and eventually short the battery).

As long as you have *some* capacity left, you will have no problems driving the car. All you'll see is a small to negligible drop in mileage, as less energy can be reclaimed during downhill stretches and red light stops, to be reused on the next uphill stretch or during acceleration. The car will still be able to start and stop the engine (no idling at red lights necessary) and run its on-board computer.

Aging of the battery is much less of a problem than a lot of people imagine, since Toyota's hybrid system never fully charges or discharges the battery - it only uses a relatively modest capacity band in the middle of the theoretical discharge cycle. This helps extend its lifetime tremendously.

 

Removing the battery would have a similar effect to removing parts from an ordinary transmission to save weight. The car would be lighter but often incapable of effectively transferring engine power to the drive wheels. For example, reverse is only powered by the battery.

The HV battery provides additional power for going up hills at high speeds, passing and taking off at lights. This allows a very efficient but less powerful engine to perform as if there were more power available. The HV battery provides 'surge' power that otherwise would require a larger, less efficient engine.

The engine is started using the HV battery as there is no 12 VDC starter. It would require adding a starter motor and heavier 12 VDC battery just to get the engine running. Alternatively, you could use an external starter cart.

As others have pointed out, the battery stores braking energy and returns it later. Think of it as a massive spring that slows the car when braking and then pushes the car forward later. This also means the brake shoes often last more than 100k miles. I'm at 118k miles and at this rate, my car won't need new pads until closer to 200k miles.

So think of removing the HV battery as:

• removing reverse gear - to save weight
• a smaller engine - to save weight
• removing starter motor and battery - to save weight
• more frequent brake repairs - from saving weight

Since the transaxle is computer controlled, the current software expects an HV battery and treats the absence as a fatal error. Removal of the HV battery requires replacement of the control computers and software. People bright enough to do that realize the weight savings are not worth the time it would take.

Fleet as well as vehicle studies suggest the HV battery in my 2003 model, NHW11 could be reduced to about 1/3d Ahr capacity. My HV battery weights 50 kg (110 lbs.) The current model, NHW20, HV battery weights 45 kg (100 lbs.) But there are other ways to save weight.

I suspect 100 lbs. could also be removed by stripping the air conditioner, heater, dash, radio and interior including the extra seats as well as the jack and the mini-tire used for a flat. There are racing techniques such as drilling lightening holes but this needs to be done carefully. Of course carbon fiber parts could be fabricated. Don't forget that the door latching mechanism and window motors are heavy. One could also also dress in lighter weight clothing, running shoes, remove body hair and the spare tire.

Bob Wilson

 

Can you remove the torque converter and clutches from an automatic SUV to save weight when they fail?
No?
Same with the battery in a Prius, however during the life of an SUV it is most likely you will need to replace these parts but with a Prius it is unlikely you will ever need to replace the battery. Problem solved because there is no problem.

Enjoy your Prius and welcome to PriusChat.

 

As others have pointed out, the Toyota hybrid system is fully integrated and the system will not function if any part is not operational. So please do not expect that the system will operate in a degraded mode.

However, the traction battery really is not a significant problem, because

1) the warranty coverage is quite long,
2) the failure rate is quite low, and
3) there will likely be a large supply of batteries from salvage yards available at low prices. For example, 2G salvage batteries are currently available for around $400 plus shipping.

 

Replacing the HV battery is similar in cost to replacing the automatic transmission on a normal car. The difference is that the HV battery will outlast the normal automatic.

Tom

 

I'd rather swap out the HV battery than try to rebuild an automatic transmission. I think the car with the new (or salvage) battery would have a better chance of performing normally again.

 

Yes, the statement is true because during the course of your drive, you will find that the battery alone can power MG2 (motor generator #2) to move the car at low speeds and gentle acceleration. If you floor the accelerator, you will find that both the battery and the gasoline engine work together to provide maximum available power. Once you reach your desired cruising speed, you may find that either the gasoline engine or the battery (or both) supply sufficient power to maintain cruising speed, depending upon whether the terrain is flat, downhill, or uphill.

However, the system requires all components to be functional at some point during your drive, as you now understand. BTW, others have asked this question, it is a very reasonable query.

I believe that the Honda hybrid system for example, can limp along if the traction battery has failed. Good luck with your decision.

 

main thing to understand is that your battery wont just quit - it will hold less charge, so your vehicle will be usable after 300,000 miles. And of course, used batteries are cheap - $400 from salvage yards (more Priuses are getting totalled than needing battery replace) - and since engine and other parts are worn less in hybrid vehicle, it will still be cheaper to maintain hybrid than petrol car even with mpg not considered.

 

The inverse question is also telling:

Can 2010 run on HV battery alone when out of gas?

The answer is yes for a limited distance, a mile or so. This can be the difference between reaching a gas station or a safe place to park versus being stuck in 'a bad place.'

Bob Wilson

 

To be precise, more 2G are being totalled than require a traction battery replacement outside warranty. No surprise since the warranty is 8 years/100K miles (or more), and the oldest 2G Prius are only 5 years old. We'll have to see how salvage battery prices change as 2G continues to age.

Note that Classic salvage batteries are in much shorter supply and cost much more - this points to a higher failure rate as well as the older average age of the population, with more vehicles out of the 8 year/100K mile warranty period.

Well, we'll see. I'd say that if a Prius transaxle fails and the owner can't find an independent to install a salvage part, s/he will pay around 3x more at a Toyota dealer, compared to an owner of a normal vehicle who will have a good number of aftermarket transmission repair sources available, assuming the owner has access to a reasonably-sized metropolitan area.

However, use of salvage parts is a very reasonable alternative if the Prius owner can either DIY or find a cooperative independent tech willing to learn how to work on the Prius.

 

I doubt this will be true when it becomes an actual choice. I guess the transmission will be quite a bit more.

OP: Google canadian Prius taxis. They are running on the original HV battery after 250k miles. And counting.

 

If you are that worried about reliability and cost, buy a 2009 Prius. The Gen 2 battery design is more than five years old and pretty thoroughly debugged and proven in use. In contrast the first year of anything has bugs in it. You can get an excellent price now on a 2009.

Also, unlike automatic transmissions, battery technology is improving rapidly. There is some hope that OEMs or the aftermarket will eventually offer replacement batteries that are better than the originals.

 

as to the battery tech, let me put this .

I have to see it yet, and I have been listening about it for 5-6 years now, some of you even more. I dont think startups can compete in this field.

Especially since you can buy used battery for so cheap, who wants brad new one for 6x more?