Hybrids

I have a 2002 Prius. So far (2 1/2 years, 45 K miles) it has been the most reliable car I've ever owned. Disclaimer: my daughter's '93 Accord has been a clear second, considering it had 8 years and 163K miles at the time. I've put a couple axles, a timing belt, brakes, a window regulator and an ignitor in it in 4 years.

The question of hybrid battery life comes up all the time. The bottom line is that everybody wonders and practically nobody has had problems. One battery was destroyed by an insane hybrid control computer (both replaced under the 8 yr/100K mile hybrid system warranty), another was punctured by a stereo installer. Otherwise the Toyota_Prius' Yahoo group's 11000 members have had no main battery failures, even though several are over the 100K mile mark. I like to illustrate the point by pointing out a Google search for "Acura transmission fail" brings up 17000 hits relating to why the Acura transmissions fail and what to do about it, while a search for "Prius battery fail" brings up about 9000 hits speculating when a battery would fail but seemingly none on any that actually did. One hit refers to a battery failing at 245K miles, but the reference doesn't take you to the original source. I'm not aware of that happening, although a Prius taxi in Canada was bought back by Toyota at about that mileage... the battery was still good.

The Prius does have a 12 volt aux battery that is more troublesome and twice the price of a normal 12 volt battery, though. Ours is still okay, but when it croaks I'm going to make the adaptation to a more normal battery. The 12 volt battery just boots the computers and runs the brake pressurization pump before the converter kicks in. I guess Toyota figured that meant they could use a lawn tractor sized battery. The pre-2004 model also came with tires that had a treadwear rating of only 160 (!) which lead to complaints of tire life. I understand the current model has more normal tires.

There is no alternator, starter or even a transmission in the conventional sense. The power steering and brake booster are electric, as is the A/C in the current model. 12 volts for accessories and recharging the aux battery comes rom a 100A converter when the hybrid system is "ready." Cruise control is nothing more than an extra brake pedal switch and a control switch assembly - everything else is just lines of code already in the hybrid computer. Reverse is still the same gearing as forward, but the hybrid computer tells the power train to back the car up, so it does. There is even forward (or backward, in reverse) torque when in gear, very much like a conventional auto tranny.

Honda's IMA system can be suped up, since it is essentially a conventional power train with a boost from an electric motor. Toyota's can't, since the entire system is under control of the hybrid computer. Adding a turbo, as one turbo mfr has suggested doing, would certainly destroy the hybrid transaxle. The engine is coupled to the transaxle by a torque limiter that looks very much like a conventional clutch without a throwout, and the "transmission" is simulated by generating AC from one motor/generator, rectifying it and inverting it to drive the other motor generator. There is some direct torque coupling but significantly increasing the engine output would destroy one of the electronic parts immediately if the torque limiter survived. Even putting headers on the engine can't improve the output, because the hybrid computer would simply get in a snit about the power not being as prescribed. For related reasons, the engine max rpm is held to 5000 rpm (maybe a little more on the current model?) by the hybrid computer. Not the choice of teenage boys everywhere, but a huge plus for engine life I'm sure.

The Honda system is adaptable to either manual or automatic transmissions. The Toyota system is not available with a manual gearbox or automatic transmission, only their "electronic CVT". Since there is no actual transmission (it is a fixed planetary differential with two electric motor/generators) there is no place to put a gearbox. Even if you found a trick to do that, it would be hard to shift a car that won't even let you decide when the engine runs. With the car in "park" I can press the accelerator to the floor. The engine always starts, if off, and gradually builds speed to some specific speed around 2000 rpm in a minute or two.

Mike

Well, good news so far, but I have always wondered what will happen 6-10 years from now when batteries need to be replaced in mass. Are they recyclable? If not, will they have to be handled as toxic waste? If so, how environmental friendly is that?

I would hope that for 2.5 years and 45K miles, ANY Toyota would be dead-reliable.

Toyota already has a program to buy them back for $200 and to recycle all the metals. Few batteries probably will ever reach the point where they will be replaced though - the battery is expected to last the design life of the car. Individual cells can be replaced and the hybrid computer even has diagnostics for determining if individual cells are performing properly. I expect the overwhelming majority of Toyota's hybrid batteries will be sold for the bounty when the cars are scrapped if current trends continue. There are 1999 model year Prius cars in Japan and their batteries are doing fine.

Mike

Me too. My previous new car was a 1984 Dodge (I plead insanity!) and it was awful from the start. A carburetor rebuild in the first week, a wiring short I spent all day chasing through the interior of the car the first year out of warranty.... At 5 years age and 90K miles it needed a new timing chain. Step 1: remove engine from car. The timing chain cover was blocked by the wheel well when the engine was mounted. You get the picture. Honda and Toyota forever! No Nissans - we shall not speak of that again.

Mike

It might help you to be aware that even tho the Honda people advertise

48 mpg on the civic hybrid, mine gets 33 in the summer and 34 in the winter after 18 months of conservative driving.

Are you sure? One can get that with a regular Civic. Not impressive at all. Maybe there is something qrong?

It makes good sense as long as the components can be reused. It would be interesting to find a site that would break down just what parts are and are not recyclable. Google...here I come....

The benefit of hybrids, especially at the current stage of development, varies a lot with how the car is used. A Civic hybrid gets only slightly better fuel economy at freeway speeds than a conventional Civic, and that is only because the engine was downsized when hybridizing the car. The electric assist is intended to make up the difference in acceleration, but there are varying opinions how well that works for the Civic.

Much of the disappointment comes from design considerations. Honda wanted to compete in fuel economy, and to get the very best economy they started with a base model that did well to start with. They could have taken the other path, economical power, as they did with their DualNote concept car... but I'm sure cost would have popped up on that adventure!

Mike

All batteries will 'last'. Define 'design life of the car' - 10 years? less? Batteries degrade on 2 factors, time, and charge. Lead acid batteries, for instance, degrade at roughly 10% capacity/year, even if kept in pristine condition. NiMH tend to last around 8-10 years at most. even if topped up - about the same life as a lead acid kept optimum. So, according to you, a Prius is only designed to last 8-10 years? sounds like a poor investment to me. I know my 17yo civic's still going strong. my 16yo volvo is utterly bombproof - nothings needed doing in the 5 years i've had that, except for the routine maintainance in the manual. tell me your prius will do that.

99 is only 5 years.Still well within life. I've got a niMH battery in my MD recorder thats from 97, and thats still going strong, despite having a hell of a lot more c/d cycles than that prius. 5 years isNOTHING to a battery. 8-10 is the end of the life, even for the very best batteries 9which include hawker sbs series, which is around $250 for a 30Ah 12V battery (also the ONLY lead acid batteries, that i'm aware of, that can be checked into aircraft luggage)

You'd think so. Friend bought an 05 camry in december. Its been in the shop 4 times, including headlight replacement, 3 times to fix the airbag system (was on its last-lemon-chance) ABS problem This for a car thats 6 months old, and 14k miles on it.... Oh, i should also mention that there's already rust on the car (and this is georgia, it don't rain that much!)

Toyota hasn't been the same since half the management resigned in 01, and they switched steel suppliers to cheap south american steel (whereas before, they'd been using high quality turkish steel, at least for europe)

Yes - I've had it back to the dealer twice - computer showed no problem - the second time the service manager asked me "well, just what mileage would you expect anyway?" I told him I didn't expect 48 but thought low 40s should be expected. He had no answer to that - as far as how the car is driven, when it says 48 city, most people would assume normal around the town driving would do. I did get 40 on a 2000 mile round trip on the interstate last summer, just to see what it would do - of course we don't usually take the civic on long trips, so that figure is pretty redundant.

Battery life is most strongly dependent on operating conditions. The flooded lead-acids in our communication sites at work have a typical life of 20-30 years, and most of those are taken out of service with the capacity still within specs (our battery guys load test them twice a year). They usually fail because the positive terminal has "grown" out of the case. I guess there is a chemical explanation for that phenomenon, but I don't know it. Anyway, the NiMH main battery in the Prius is kept within a relatively narrow range of state-of-charge, temperature controlled, and with charge and discharge rates limited. It should be good for the life of the car, as Toyota says. 15 to 20 years should be about right. I would be as surprised at failures within 10 years as I would at lasting to 30 years. Toyota is betting their own money there will be negligible failures before 8 years/100K miles (10 years/150K in California, IIRC), so I feel comfortable. More than that, Toyota's credibility would suffer horribly if there were such a rash of failures, and I won't insult Toyota's leadership by suggesting they are that reckless. I think it's more likely they know exactly what they are doing - a lesson our stateside companies should learn.

What is the design life of a car? Only Rolls Royce has had the nerve to advertise that; they used to advertise 50 years. The standard in America was implicitly 10 years for a very long time. Most quality cars, like Honda and Toyota, are probably around 15 years - certainly more than 10, certainly less than 20. Your Volvo and mine (an '85 765T) also had design lives in that range. There is no percentage in making a car last 20 years, and 10 years builds a reputation for schlock (like GM, Ford and Chrysler have), so the 15 year target is the sweet spot. It didn't work out well for my '85, which has the French wiring that had a 5 year life, but that's life. At least yours was built after the biodegradable wiring era.

The central point is that every individual car reaches the end of its life sometime. It may be an untimely end in a collision, but more often it needs a repair that the car is no longer worth. For my last Volvo, a 1970 145, it was when the car was no longer worth putting a water pump in. (I never thought to question what the life of the water pump is.) This '85 won't survive its first turbo failure - at 235K miles it is overdue. I had a 1970 Mercury Capri that was no longer worth a U-joint, which was integral with the drive shaft. It's always something. With the Prius it is very unlikely in my estimation that battery failure will be a significant factor. I expect at least 15 years from the car, and I expect the battery will still be servicable at that point. If you feel differently, you'd be wise not to buy one.

Mike

Then you have a very low level requirement. Its slightly erring on the cautious side to say that lead acid capacity decreases at 10%/year However, after 10 years, you're left at 35% capacity. oh, the load will still be ok, but the caacity will be shot to hell. The growing terminals are the exact same reason that the capacity drops - chemical action.That 35% is also some eavy rounding. after 20 years, you're at

11-12% capacity. This is, as i remind you, keeping th batteries in their optimum condition.treat them sub-optimally and they won't do half as well.

Toyota has very little credability with me anyway, but then, are you SURE its their money they're bettingwith? there's a long running dispute between toyota and pastafont steel, for instance, where toyota owes pastafont some $5m for steel its not paid for. $5million+interest over 5 years buys a lot of hybrid battery sets. If, however, your batteries are claimed to last 10 years, i'd be very interseted ina bout 10 sets of them (I build Electrically powered vehicles as a hobby) so i've contacted Matsushita, since this kind of longevity is something Saft hasn't been able to give me with their

12Ah Sub-F cells (nice cells, especially the max discharge of 100A/cell, which moves the bottleneck to the controllers - a 1500A 150V controller isn't as easy to build as you might think - for those that aren't up on your maths, thats about 300Hp, less losses to efficiency)

Dissapointing to say the least.... :-(

Hello, I read an article about Hybrid vehicles in a car magazine. The magazine staff used a Hybrid vehicle for about two years. Each of the staff members that used the car (for free) for trips had to write a report related to problems and miles per gallon. The consensus was that gas mileage was great when the trip involved lots of city (aka stop and go) driving but was very poor when the trip involved lots of freeway and interstate driving. The reporter that wrote the story indicated that the electric engine kicks in quite a lot in low speed stop and go driving but rarely kicks in on interstate and freeway driving. It was his opinion that this was the reason for the differences in the miles per gallon. The conclusion: If you plan to do a lot of city driving--buy a hybrid. If you plan to use the vehicle for lots of freeway and interstate driving--don't buy a hybrid.

Which kind? The series hybrid type such as what Honda does, or the incredibly complex parallel hybrid type such as what Toyota does (and licenses to Ford)?

If you understand what a hybrid does, and what problem it's trying to solve, this is no surprise at all.

20 years is the standard design life for communications lead-acid batteries, although cell sites often go for the quick and dirty versions with 12 year design life or less: and select "Flooded" technologies The load test is a complete capacity test; loss of 20% capacity is the trigger for replacement. Most have less than 10% loss in capacity after 20 years and are usually budgeted for replacement within 30 years - earlier if they show signs of case failure or (more rarely) loss of capacity.

Mike

From the description it would have to be Toyota's series/parallel Prius.

Exactly. In theory, a serial hybrid could be made with a very low power engine and using just the electric storage for acceleration, and in that way get a measurable improvement in freeway economy. But for the forseeable future hybrids just don't have a significant advantage at freeway speeds. Cars like the Civic are pretty efficient at that already and there is little room for improvement.

Mike