When cars are new and under warranty are one thing but old cars are another. For example front wheel drive cars are awesome when new but as they age the CV joints and timing belts can cause problem which is why some suggest a rear wheel drive as a simpler alternative in the used car market.

As our cars age some parts are going to wear out. In fact some Insights have got old enough that their packs have given up the ghost and need replacing. I've seen prices from $1200 (battery only) to $5800 (entire IMA system). Those prices are high compared to the cost of a new car and really, really high compared to the remaining worth of an old car.

Now I think the Toyota system is fantastic. I'd love to have a newer Prius but you couldn't pay me enough to drive a used HSD equipped car with failing "hybrid" parts. HSD requires that every single major part be working near perfectly. They just plain will not work unless both motors and the computer and the battery are in good condition. The "full" hybrid system is totally integrated into the the vehicle and the car will not work without it. If the battery fails you gotta get it replaced (correct me if I'm wrong about this).

IMA equipped Honda's on the other hand will work fine without the IMA battery (the part most likely to go bad). The car will lack that nice "hybrid" boost but the ICE will still work just fine and the car will still be worth something even without a battery replacement. With some slight modding the entire IMA system could go away and the car would still be drivable.

Old Hondas will make better cars than old Toyotas.

Depends... If the battery is the only major component that fails in older Prii, then I'd say you still have an excellent and valuable car. Most cars have parts that wear and need replacing, such as clutches and DC starter motors, not to mention brakes and real CVTs and automatic transmissions. AC motors are highly reliable, much more so than any ICE, so they aren't likely to fail until well after the engine in worn right out. Brakes on a Prius will last way longer than ordinary cars and probably longer than IMA cars due to their larger generator and battery, so that can add up over the life of a car as well. I don't think having the battery replaced will be as big of a deal as people think, and they are likely getting cheaper as they become more plentiful as more hybrids are on the market. If you need a $1500 clutch job, CVT rebuild or battery job at 150,000 miles is it really any different?

You're probably right about people who don't replace the battery, maybe a Honda will keep on putting along, although doesn't the 12v battery get charged from the HV battery? And you still need to keep replacing the small 12v battery quite often since it would be much more abused from having to start from it all the time, if it would be able to charge it.

2001 Prius Photos       2005 Prius Photos
'97 Prius Simulation Prius inner workings

Since I plan to keep my car 350K miles, I'll likely be driving my last segment with a flat battery...But still driving which was a big concern of mine.

Efficient drivers do it better.
1003 miles a tank personal record. 74MPG calculated. HCH1 CVT

Being a Prius II owner i might be somewhat biassed , BUT:

The prius has an 8 year warranty on the COMPLETE HSD system, so the first 2 or three owners have nothing to worry about in the first place. Then the fourth owner:

- buys an engine that has to date only run in its optimal operating range
- has no gearbox, clutch, start motor to worry about (which allways were costly repairs in my second hands)
- has an onboard computer that will take every action necesarry to keep the batterypack in good health (including starting the engine for the sole purpose of filling the battery pack)
- will have a car graveyard full of 8 year old crashed Prii that will serve as cheap replacement source for the odd battery module that does fail (you only need to replace individual modules, and sitting in the middle of the car, they are likely to survive any crash)
- will probably still be using the first set of brake discs, and pass them on to successive buyers in good shape.

Let's wait and see what secondhand prices are within a year or two.....

So far my 2 cents worth, Lars

Interesting, we seem to be split down the middle and all seem biased based on the type of car they drive. It also looks like us Honda guys thought about this very issue before we made a purchase. In my case it made it easier to "settle" for a Civic, having wanted a Prius first.

Did you Prius guys think of this when you purchased your car? I do understand that on both cars the "hybrid" parts are under warranty for a good long time, even more so if you live in California. I was talking about what happens when the car is so old or has so many miles the warranty is no longer.

As far as crashes go you might be correct but one of the Insight replacements was likely do to minor crash damage that did not show up right away. That story has a happy ending with Honda extending the warranty and covering most of the cost.

The question I have is have any of the Honda people actually tried running their cars with a dead IMA battery, or disconnected? I have my doubts about the overall functionality of the car in that case, since a lot of the systems rely on having the HV battery power available, such as the 12v charging system and the autostop/start function it would seem as if the HV battery being dead would cause more problems than you may think.

Another good question is what battery pack will last longer? The Toyotas use a larger battery, and obviously use different program to maintain as well as being rectangular cells instead of the D cells... Hard to know for sure what will last longer, but there's probably going to be a considerable difference and it will be interesting to see how it plays out.

2001 Prius Photos       2005 Prius Photos
'97 Prius Simulation Prius inner workings

I am heartened by the report of a Vancouver Prius 1 Taxicab was repurchased by Toyota and replaced by a 2G model. The taxicab had over 200K miles on it and worked perfectly. Toyota bought it back to study all of the things that went right. If a Prius 1 THS system can survive 200k miles in taxicab duty, I am quite confident that a 2G HSD will do better, especially the way I drive it.

I don't really know if HSD can run without the HV battery. But as someone earlier mentioned, since there are twenty-eight 7.2V modules, it's not likely that all will go bad at once. The Battery ECU would compensate by optimizing what is left of battery capacity. When battery voltage is no longer sustainable, I suspect that the Battery ECU would tell the Engine Control Module to keep the ICE running so it would function much like a normal car. I have no knowledge of what would actually happen but is seems that the engineers would have designed such a failsafe into the system.

I plan on finding out for sure, many years down the road. I think 300-500K is my target. On a related note, since I have successfully added battery capacity to my Prius, and have since removed said capacity, I know exactly what to do if my HV battery goes dead.

It's a Wonderful Day for Science!

You Prius guys do have a point about the clutch. I think that your PSD should last basically forever while us Honda guys will eventually have clutch (MT) or cone/belt (CVT) problems. It is nice to hear about the Toyota pack being modular.

BTW I don't think that the IMA pack is required to charge the 12v batt. The motor/generator combined with a DC/DC converter provides an alternator function. I'm almost sure that a Honda will run without the pack as long as the rest of the system is OK.

If anybody know more details on either brand of car running pack crippled please add your 2c. It looks like quite a few of us plan to keep our cars long enough that this will eventually be an issue.

Priuses have planatary gears, and they do wear out! Ever work on anything with them, fun. Kevin

2004 silverblue 5 sp.