Preparing for hybrid battery failure?

The Prius cannot be driven without a functional traction (large "hybrid") battery.

In fact, if the traction battery is bad, you will not even be able to start the engine
because the traction battery provides the power to spin MG1 which turns and
starts the internal combustion engine.

Replacing the traction battery will cost you many Benjamins. If the car is in good condition, it
might be worth it to invest the $2000 to replace the traction battery with a rebuilt one.

If not, you'll be better off trying to sell your Prius to a private party - a dealer won't offer very much.

 

Chances are it won't happen so enjoy your car until your ready for a new one! If it does pack it in you can pick one up from a wreck or have it rebuilt. Probably less than you spent on the past items you replaced. H

 

What are the signs of a weakening traction battery? We have an '05 w/110,000 miles, and have been noticing that the charging gauge swings from the low to the high levels very quickly. Whereas it seemed to sit in the blue range most of the time, now it is in the red or green ranges a lot more of the time. Overall mpg performance has not changed, though. We are in hilly Colorado, so a lot of downhill grades where the charge can go full green. One odd thing, when at full green charge and stopped, the engine continues to run with the charging arrows switching directions. Like the charging system is confused. Any ideas?

 

Seems that your traction battery might be reaching the end of its life. The battery charge gauge status should not vary that much. You should visit your local Toyota dealer ASAP and have the traction battery and the HSD system tested before your battery fails completely.

 

This is a sign that your battery is losing capacity. Many older Priuses will have reductions in battery capacity but wont necessarily notice it so much if they drive in flatter terrain. The Prius will tolerate a fairly large reduction in battery capacity before it throws a code, and though I'm sure this is partly to minimize warranty claims, tests have shown that the Prius can still get very good MPG even with quite a large percent of the battery capacity gone.

Remember that losing capacity (amp hours) is not the only way a battery can fail. Other problems like shorted cells and rapid self discharge will badly screw up performance and cause it the throw a code. If you're still getting good mpg then it's most likely just a loss of capacity, and at this stage you can probably just keep driving it. I assume you're out of warranty right?

 

This is just because you are reaching full 8 bar SOC more often now (due to reduced battery capacity). The Prius uses one of it's electric motors to spin the engine as a load (without fuel injection) so it can drain some energy from the battery when it's got too much. Think of it like cranking the engine in a conventional car with the fuel line disconnected and for no other reason than to purposely run down the battery. This is basically normal, happens fairly often to me too, but only at 8 bar full green SOC.

 

Well Dave, I have an 01 w/ 117,000 and an 06 w/ 109,000 and I'm in the same boat as you (especially w/ the 01). It is good that you're thinking about it now so you can proactively prepare. Proactive = Good, Reactive = Bad, Inactive=Worse (I learned that at Navy Leadership School).

My plan is to fix the battery myself by replacing the bad cells and matching capacity (essentially rebuilding the battery pack). This is about a $100 fix but, requires a lot of work and time. After doing a ton of research on the subject, I've concluded that it can be done by the experienced DIYer.

 

I have a 08 with 123KMi on the clock which I bought with 85KMi and I am mildly concerned also as to when the HV will fail but more from the standpoint of being stranded a few hundred miles from home1.
The Emissions Testing Machine could not believe the Odometer readings last week when it was tested for the first time and showed 123,000 miles.

I have noticed that the full green SOC/ engine spinning 'phase' after long downhill high speed stops twice in Alpahretta and twice after long downhill high speed stop after running at 75mph on the Interstate for 175Mi.

MPG reading taken this past weekend with an SG2 with a Ta 65F on a food trip into Decatur showed 73.4mpg for the trip back with gas that we are curently getting for this time of year. I am not sure how much the ECT Spoofer contributed to that number.

The current plan is to use PriiDash2 to monitor the HV Battery as it logs a number of HV Battery readings. The logs will have to be analysed to see if a block, which block is going far out of balance.
A possibility would be to perform a re-balance to extend the battery life another 123K

As for the electronic circuits 'wearing' out, they are built from parts that are only warrantied for 4 years. Early failures are probably 'bathtub' curve failures from the bell curve an should be covered under warranty.

 

Dang Winston, you do log some miles don't you?????.

My experience tells me that you're fine with an 08. If I had an 07 or above, I wouldn't really worry about the pack for another 2-3 years. Most packs that are failing now are 05 and below.

I am really amazed at how many packs haven't failed yet. I really find it astounding that the pack in my 01 is still going strong (knock on wood). The chances of one failed module out of 38 over an 11 yr period must be greater than 50% (guess). I haven't seen too many stories of Gen I's on their original packs.

 

If my job goes the way I think, I may have to log around 800 mi/week next year. Priidash2 is set to log a lot of miles.

 

Honestly, I think folks worry too much about the traction battery in these cars. There are other systems in these cars that are just as expensive or even moreso than the traction battery. The fear comes from the hype that certain individuals have put on others trying to knock the technology. I believe it stems from Big Oil and then rolls downhill to the little guy (us). IMO, enjoy the MPG and keep driving the Prius. The chance of your traction battery failing is a lot lower than you think. I am not saying they don't fail. What I am saying is that the percentage of failure's is in your favor. If you look at the numbers here on PC and the amount of car over 200K with the original traction battery, you should be able to see what I am saying.

200,000 Mile Club | PriusChat

One thing that does stand out in the reports here on PC, those whose batteries have gone south were either in hot climates or extreme hilly areas (mountains). So even geographics has a play in it from what is being reported. Those have reported failures usually show up after 120K or higher. Many in the 200K club here on PC report they are still running on the original traction battery.

Ron

 

The HV battery, like many other auto parts, needs to be considered a consumable as it will fail at some point due to the cells slowly getting out of balance. The other failure mechanism is overheating as was noted earlier in this discussion and can cause an early failure. Mine failed at 195k miles and was replaced at a cost of $2000 with a ReInVolt. That comes to about 1 cent per mile which is similar to the cost per mile of tires or brakes (except in a Prius where brakes usually last along time - mine are original at 232k miles). Note that gasoline cost is about 7.5 cents per mile in a Prius at current prices.

JeffD

 

I live at the bottom of a hill which must be climbed immediately after leaving my driveway. My habit of driving off immediately was causing me to reach the top of the hill with as few as two to three bars of battery, from a start of six or even seven. From tips learned on this forum, I now let it "warm up" for as little as 30 seconds before driving off and generally reach the hill top with six bars. I have come to believe, also from reading PC, that the less that battery gauge swings, the kinder we are being to our traction battery and the longer it will be before it expends its last cycle. Hilly terrain makes this difficult but we often may choose how fast we go up a hill and can influence whether or not battery power is being expended to maintain the chosen rate of climb. But as others have said in this thread, any driving style should render the big battery no more troubleprone than other Prius systems. For instance, I try and hypermile to a certain extent (climb slower than descend, drive under 60 to 65 MPH, keep the heat off until reaching the expressway) and thereby maintain between 50 to 55 MPG, depending upon season. But those that totally ignore this somewhat extreme driving style will still get around 45, in all likelihood, which is WAY ahead of what their previous vehicle was capable of. So just enjoying the vehicle is by no means a foolish manner of operation and should not make it any more expensive to operate than most other cars. PC members know better but my impression is that if there are greater maintenance costs, and I'm by no means certain of that, they are more than offset by the high fuel economy. Like all Toyotas, things rarely break. Many Honda/Toyota owners experience no mechanical failures in the entire time they own a vehicle and I mean well into the 100,000 to 200,000 mile range. My 205K mile '04 appears to fit into this category. It's repair history appears to primarily consist of recalled water pump replacements.

If you will note the vehicle parked next to my '04 in the avatar, you will realize that I am one of the very few that accepted a significant LOSS in fuel economy in order to drive a Prius. I remain pleased, to this day, with that decision.

 

Dave,

The MFD failure is a classic that I repaired DIY for about $35 in tools.

The 2004 Prius Stereo is a piece of junk. The repair is to install a 3rd party stereo (my pioneer 33HD cost $250 installed at the auto stereo shop).

My HV battery was a bit more costly when it failed at 195k miles ($2000 for a ReInVolt).

I did have a failure in the steering column that cost $1000 to fix and had to put in a set of Struts for another $1000 as well as 5 sets of tires so far (about $400 each).

Adding that all up, it pales in comparison to the $15k that I have saved in gasoline over the 232k miles I have driven my Prius.

JeffD

 

I am living proof that any numbskull can replace the MFD. It's modular. There are tons of YouTube videos on how to remove the unit. Heck - much of the entire dash simply snaps in. As for traction battery replacement ... stop worrying about it. Worrying won't make it happen sooner or prevent it. The reason the warranty last 150,000 miles in carbs States is because the traction pack in the majority of instances will usually go for 200,000 miles or more. Why do you think so many companies use them for Taxicabs now days.

SGH-I717R ? 2

 

My 2002 Prius navigates a few big hills in its common travels, but I do not drive aggressively, or like I am being filmed for a car ad. At just a shade over 200,000 miles, the engine light, dashboard warning marker, and MFD warning symbol came on. After about a day, while traveling at 40-65mph, the dashboard brake light would come on and the engine would rev, acting like a traditional-transmission vehicle thrown into a very low gear ratio: acceleration power was almost nonexistent. I could limp along by pulling over, shutting off the car, and restarting it. This got me to my destination, once the symptom began, and then the rest of the way to the repair shop, where the analysis of the codes in the control computer revealed several failed cells in the hybrid battery.

I noticed that my mileage had begun decreasing in the day or two prior to the lights coming on, and that charging behavior, particularly at stop lights, had become more pronounced - engine running when it would ordinarily be off. Since I bought the car for about $4200 below expected retail, back in 2002, I justified replacing the battery and trying to get at least 5 more years of use from the car. It still registers >49mpg on the MFD gauge, or about 46.5-47.5mpg as calculated at fuel fillups.

 

How much was the battery replacement cost Joseph?