Hybrids - Toyota vs Honda

I can't predict the future, but although a number of 2001 Prius are
approaching 200K miles the HV batteries so far have been supremely reliable.
It's instructive to Google "honda transmission fail" and look over some of
the 391K hits. Why they fail, which ones fail, what to do about the failed
ones... and then to Google "prius battery fail." It returns 70K hits
presently, and the only one I see offhand ( http://tinyurl.com/ahc2x ) that
purports to be a failed battery is clearly bogus: the complainant says the
battery released sulfur dioxide in large amounts when it failed, but there
is no sulfur in the NiMH battery Toyota uses. The rest are mainly
speculation about how long the battery might last. If you are in California
or a handful of other states, Toyota will pay the full replacement cost for
10 years or 150K miles. In the other states it is 8 years or 100K miles. Not
sure about Canada.

Mike

 

I don't think that is a safe conclusion at all. With a number of Prius
approaching the 200K mile and 5 year mark, there have been few enough
outright battery failures that validating them is difficult (obvious hoaxes
are common). It is more likely as Toyota indicates; most will never need a
replacement battery. If somebody does need one, used batteries are often
offered for $400-$1000 US on ebay, courtesy of road accidents. To test the
battery, the multi-function display includes a diagnostic screen that
reports individual cell health (one of those secret sequence things) and the
cells are individually replaceable.

Every vehicle dies of something. I've scrapped a Mercury Capri because it
needed a new driveshaft (integral u-joints!) and the price was over $200. To
assume HV batteries will be the death of most hybrids is quite a stretch,
especially given their track record.

Mike

 

Can you pass on the sequence, please? I'd love to have it handy
for my UK-spec T4 Prius (new Aug 2005), for occasional checking.

More generally: there are so many ignorant people, ready to make
sweeping and ignorant statements about hybrids that I've learned
to disregard them, or (for fun) pick out the weasel-phrases used
to insure against contradiction. The bleeding things work, now.
I am assuming Toyota (with Honda, and whoever else undertakes to
manufacture advanced vehicles) do accelerated life testing &c &c
with a view to ensuring customers don't get mightily cheesed off
before they've had value for money. Time, not ignorant opinion,
will tell.

FWIW my Toyota dealer tells me today that the UK price for a new
main Prius battery (w/o labour charges or taxes) is GBP 1321.35,
which I hope helps to focus the discussion. (Side note: earlier
this year I posted a substantially lower price, also supplied by
my dealer; but I think he must have misunderstood the question.)
I would expect this price to fall as design refinements are made
and production ramps up -- what to, who knows.

 

But what problems do they solve, and what other solutions are there for
the same problems?

They solve exactly one problem: recapturing braking energy to re-use on
acceleration. There's only one place where that works: city driving.

The requirement for braking came from the burning of petrol to create
acceleration in the first place. Must we burn petrol to create the
acceleration? Can anything else solve that problem?

They're also more expensive to make and to buy. That's a problem in and
of itself. If we're trying to save on petrol, can we use any other
motive source for acceleration?

If so, can that other motive source be purchased cheaper than the hybrid?

For example: can a diesel engine solve the problem better/cheaper/more
reliably than a hybrid?

Can I run a diesel and spend less money, or no more than the same money,
as a hybrid? Let's say I spend the exact same amount of money per mile
to motivate the diesel as the hybrid. Now it comes down to maintenance
and reliability. Is the diesel cheaper or more expensive to maintain?
What about the reliability--can I get the diesel fixed cheaper? What
happens when I go out in the country somewhere--can I rely on the magic
black box of software that the hybrid depends upon, or will a diesel be
more reliable because it doesn't depend on a computer just to run?

There are so many questions to ask yourself once you dig down.

I prize reliability and simplicity. The Toyota hybrid fails the
simplicity test horribly, the Honda hybrid much less so, the diesel
virtually not at all.

And frankly, it's all about MY pocketbook. Which one, over 200K miles,
cost me the least out of pocket to buy, maintain, repair, and insure?

 

At the risk of turning this into one of those endlessly circling
threads, I'll try to go through your points, which are reasonable
but based (in a couple of places at least) on insufficient facts.

All of the following is AFAIK, okay?

At this stage in the development of hybrids and advanced vehicle
design in general, the industry is having to play catch-up after
decades of, frankly, unforgivable negligence. Now that pressure
is on to make best use of resources, they are seeking answers.

So these vehicles are, to some extent, test beds. The initial
experiments have been done at the factory and have reached the
stage where the product is deemed good enough to be released for
long-term market testing. As with ANY product, there will be
imperfections, which we hope will be removed by re-design.

The main problems the Prius (and, I assume, competing designs) is
_trying_ to solve seem to fall into at least three areas: better
conversion of the fuel (petrol/gas/&c) into a form useful within
the vehicle (eg, movement, light, heat, communications); reduced
waste of same thereafter; improved control generally to make the
car more efficient (re: energy) and a good drive (eg, responsive,
surer-footed on slippery surfaces, positive steering+braking).

On top of those perfomance-related issues, there is the question
of improving the vehicle's green credentials. Now, I know that
for some people "green" is a red-rag-to-a-bull trigger word. By
it, I mean "how to reduce the amount you throw away needlessly".
Manufacturers are learning to waste less whilst building the car,
waste less whilst it's working, recover more when it's scrapped.
It's not a political question, unless we insist on making it so.
Saving makes such bleeding obvious sense, I'll stop beating that
drum right there.

Well, no, they already solve more problems than that. The Prius
uses several tricks to cut fuel consumption. The regenerative
braking is significant, certainly; but the greater effiiency of
the Atkinson engine (less power for the same capacity, but much
greater efficiency) is the first major plus. Then, yes, waste
due to braking counts for a lot. On top of that, the electric
motor does a better job of start/slow/stop movement than a plain
old ICE would, as technology stands now. Finally, there is the
control system, which works behind the scenes, choosing optimal
strategies as best it can.

A dangerous generalisation. The Prius has bits conventional cars
lack, yes (eg: battery, electric generator and motor, inverter,
planetary gear), but lacks some conventional parts (eg: clutch,
gearbox); and some parts are simplified or smaller (eg: 1.5 litre
petrol engine, 45 litre fuel tank, lightweight transmission). A
slew of parts are entirely conventional and can benefit from past
developments and existing production methods (eg: wheels+tyres,
suspensions, hydraulic brake components (augmented by regen.),
lights, seating, steering, structure parts, body panels, paint
and plastics bits). Get the idea? It's a trade-off.

And, to repeat something that really shouldn't need repeating, in
an age when we trust horrendously complex gadgets with our lives
every hour: complexity does not have to mean unreliability. The
Prius braking system, for example, is full of feedback loops that
cope with small failures. Go look it up: Toyota are fairly free
with their literature and sent me detailed techical info.

It'll be something that surprises us -- count on it.

Time will tell. My money is on someone developing a diesel that
can be fitted into a hybrid, thereby gaining the best of both.

Indeed. I totally agree with you there.

One of the nice aspects of a free market is that _you_ can choose
not to participate in the Great Experiment. With more of us out
there, trying alternative solutions, we may find a better way a
lot sooner. So go for it. Or not. Thus far, I like my Prius.
It cost me significantly less (purchase price) and serves me more
to my taste than some quite swanky cars I looked at.

 

You forgot one very impotent part of that equation....REPLACEMENT cost. The
hybrids, all of them, cost more to buy than conventionally power vehicles of
the same size and equipment. They will cost more to replace as well.
Especially if the batteries are depleted. The fact is the premium one pays
to acquire a hybrid will generally buy ALL of the fuel, used by a comparable
conventionally power vehicle, for three to four years. For the average new
car buyer in the US that replaces their new vehicle with another new vehicle
in three to four years that can mean all of the fuel for as long as they
generally own their vehicles. Personally I hope more buyers choose hybrids
to save the planet, that will stretch the supply of fuel for those of use
that prefer high powered, safer, large vehicles. The only problem I see is
if the consumption of fuel, in total, is going down the price of fuel will
rise for those that have trouble buying fuel at todays prices evn for hybrid
owners.


mike


"Elmo P. Shagnasty" > And frankly, it's all about MY pocketbook. Which one,
over 200K miles,

 

My satellite phone has the same type of battery as used in the Pruis. It is
about the size of a thick postage stamp and it costs $52 to replace.


mike hunt

 

Wanna bet the replacement cost is prorated, not fully covered by the
warranty?

mike hunt

 

Probably closer to 8 years, the life expectency of a hybrid battery
pack.

Or longer.

I'm not. It's a diversion from hydrogen technology. Besides, battery
production is an incredibly toxic industry. Your trading one plague
for another.

nb

 

At the risk of turning this into one of those endlessly circling
threads, I'll try to go through your points, which are reasonable
but based (in a couple of places at least) on insufficient facts.

All of the following is AFAIK, okay?[/QUOTE]

Good discussion, thanks.

That pretty much sums it up. "Green" isn't a car, it's a holistic
philosophy.

Personally, I have trouble evaluating the control system in a vacuum. I
need to evaluate the benefits of the control system against the cost of
the fact that the control system is incredibly complex--and complexity
brings its own set of problems to the table.

Now we're into the law of unintended consequences.

Many cars can use less complex transmissions as well. That they don't
choose to is another matter.

Pull back a bit, and see what happened when a hurricane hit our
incredibly complex and teetering on the edge energy market.

Complexity puts you that much closer to the edge.

That's such a simple concept, I'm amazed it hasn't been done. Didn't I
read in Car and Driver magazine some time ago that an idling diesel
engine consumes virtually no fuel? This was in regard to big rig
trucks, but still. The question came up about why truck drivers don't
shut their engines off in situations where car drivers would, and that
was the answer.

Frankly, if anyone can do it it'll be Toyota.

I find it mildly humorous that Ford has licensed Toyota hybrid
technology for their Escape...

 

hybrids don't just work by capturing braking energy.

They run a more fuel efficient cycle with a longer expansion stroke.
The Miller/Atkinson cycle. They can do this because acceleration is
supplemented by the battery. They also have a smaller engine b/c it
can use batteries to accelerate.

By using the Miller cycle they get a higher % of energy out of the gas
and into the drivetrain.

It's very ingenious.

Hydrogen is probably never going to "be here". You need a fuel source
to get hydrogen. Hydrogen is very hard to transport (harder than
natural gas which is difficult enough) and there are no cheap "fuel
cells". The advantages of a liquid fuel are great.

I think the next step is using a smaller gas engine and a
larger/cheaper battery that you can plug in. You could plug it in for
an hour a night and that would take you maybe 30-40 miles. On longer
trips and under acceleration the gas engine would turn on. That way
you'd be replacing gas with electricity, which can come from
nuclear/coal/wind whatever.

 

Regenerative braking is very far down on the list of values in
hybridization. The essential purpose is to use the primary power source more
efficiently. Putting a 240 hp engine in a passenger car to cruise around
town at 35 mph is extremely inefficient. Using a 50 hp engine to do that is
far more efficient, but responsiveness suffers badly. We are in the infancy
of hybridization now, but as the power technology advances a 50 hp hybrid
can be more efficient than a 50 hp conventional car and provide better
responsiveness than a 240 hp conventional car. The difference is made up by
stored electric power.

In actuality, a car would have to be pretty small to warrant only a 50 hp
engine. The design becomes straightforward, though. The power necessary to
climb a 6% grade at the prevailing maximum speed (75 mph in the US) at
maximum gross weight is exactly the engine power needed. For a mid-size car
that is in the 100 hp range, maybe slightly less.

The side effects of running the engine at higher power levels are valuable,
too. Hybridization increasingly separates the engine from the driver
control, so there are no issues with suddenly mashing the accelerator.
Emissions are much easier to control as the engine comes under computer
control.

I can understand why there isn't a lot of enthusiasm for the current
generation of hybrids. Not only do they have a limited track record, the
level of hybridization is not enough to knock anybody's socks off. (Well,
mostly not. See Honda's DualNote
http://world.honda.com/Tokyo2001/auto/DUALNOTE/ for a glimpse of what is
possible.)

Mike

 

Your battery has the same basic chemistry, but is a very different animal.
In portable electronics the most important design characteristics are power
density, light weight, barely affordable replacement cost, and short,
spectacular life. The last two are economic considerations. In the Prius
power density and light weight are not very important at all, the
replacement cost is what it is (since it is not designed to be replaced),
and the life is designed to match the life of the rest of the car. If you
were willing to have a much larger and heavier battery that used only a
third of its potential capacity, and a very sophisticated and expensive
charger that was always connected to a charging source when the battery was
in use, your battery could easily outlast your satellite phone. I doubt you
would like it, though.

Mike

 

Nope - 100% covered.

Mike

 

So you would like us to believe the useful life of a Pruis is 8yr 100K? A
Corolla that can be had for 5,000 less will easily last to 200k or more,
don't you think All the more reason one would be better off buying a
Corolla

mike

 

No - the *warranty* is 8 yr/100K miles. Engine warranties (like the one in
the Corolla) are typically 3 yr/36K miles, but I'm sure you expect more.

Mike

 

We shall see. NiMH batteries typically have a reduced charge cycle
lifetime compared to NiCADs. That is one reason NiMH never caught on in
power tools where a contractor might cycle a battery several times per day.

Lifetime in cars is going to be highly variable depending upon usage
patterns and random manufacturing variations.

John

 

One problem with that is the fact that the stored electric power
eventually runs down. It would not be fun to be in the passing lane on
a long uphill section of road going around a vehicle only to discover
that your battery storage has just been exhausted and that the available
torque is suddenly reduced 50%. Yikes!

One thing hybrids bring into the equation is a significant depenence on
near term prior history to a degree which conventional engines do not.

John

 

It's all a matter of design. In your example, a properly designed hybrid
will not run out of passing power because the engine power was enough to
maintain full legal speed, while passing power is available because it was
not needed to reach the cruising speed. A major reason multi-hundred
horsepower engines are used in passenger cars today is to provide that
margin, in spite of the economy penalty the vast majority of the time.

Even in the previous generation Prius - the one we have - our battery has
never dropped to "empty" (actually something like 50% charge) although we
live at 7000 feet and have made trips with ful load to Washington state and
the LA area. I've never heard anybody complain about that happening, either.
It just isn't a problem.

Mike

 

The Prius first went on sale in Japan in 1997, 8 years ago. I don't have
solid information, but AFAIK no reports have come out about failures of
those batteries.

As you say, we shall see.

Mike