My '06 Prius is the only new car I ever bought, and it has never once failed to bring a smile to my face. Especially when I get stuck in a traffic jam and the engine turns itself off, while everyone around me is sucking fuel and going nowhere. But here we are six years and 78,000 miles from the showroom, and I am beginning to wonder about the battery. The dealer warranty covers it to 100,000 miles but I am worried about what might happen after that. Some questions: 1 - Are there any data about Prius batteries from this or earlier eras? Do they have a reputation, for example, for continuing to perform like new, or for dying at 100,001 miles? 2 - Are there any warning signs, like gradually worse battery performance? So far mine runs like a champ. 3 - Are there any steps that can be taken to prolong battery life? 4 - What other questions should I be asking? Thanks much, inkslave
1... there's all kinds of data.. like people putting over 300k miles on them.. factory testing that simulated 20 years of wear and charge cycles (estimated 500k miles) 2. it will slow down more.. your mpg will drop.. power drops... overall drop. warning lights too.. the system will know when something is up or not powerful enough to do it's job. 3. keep it in a happy temp range. if it's hot out, keep that a/c on so the cabin air cools it.. if you're comfortable inside the car, the battery is comfortable. don't spend your life don't 0 to 60's... don't tow things every day... (even though i get better mileage when i tow)... there are lots of little things.. none of it matters too much. the system takes care of itself. 4. is my normal battery about to die?.. probably... your 12v battery last anywhere from 5 to 6 years.. some last longer.. some shorter. it depends on the abuse. your 12v battery is the one that will get you stranded at a grocery store or other daily run around spot. some on here are starting to add water to their 12v to keep maintained. i've heard great success from this. you may want to flush your psd fluid if you haven't done that... (i heard earlier is better than later) there are other little things here or there. others will chime in.
Note what Cobrakid has said and then watch the following (it's after the ads) and this should put your mind at rest; CTV British Columbia - Hybrids prove very reliable - CTV News 1,000,000 km is about 600,000 miles.
When the time finally comes, and it should still be a long way off, there are plenty of salvage and rebuilt batteries on the market. Tom
My 2004 Prius HV battery lasted 194k miles (7.5 years). Your mileage may vary as they can wear out sooner in hot climates. A rebuilt battery from Remanufactured Hybrid Vehicle Battery Packs cost me less than $2000 installed which comes to about $0.01 per mile. A new battery at my dealer would have cost $3300 installed (about 1.5 cents/mile). This is a reasonable maintenance cost item so drive you Prius and don't worry about it. JeffD ps I'm still using the original 12v battery at 205k miles.
2006, 78K -- no problem whatsoever to expect at least a few more completely trouble-free years. Failures reported here so far have been older, higher mileage cars life Jeff's.
You will sell or trade in your car with the original battery and then you will wonder what you were worried about.
I have 06 with 151k miles. So far so good. I checked the voltages and internal resistance of each HV battery module using Torque and they are doing great. There is no weak module.
Weak modules have a higher rate of self-discharge. It is the hardest thing to check. Next time you let the car sit unused for a few days, take a snapshot of voltages first thing in Ig-On. If they are all within .01V, then you are in good shape. If you've got a block more than 0.1V lower, then it is on its way out.
I am not battery expert but wouldn't it much easier to detect weak modules by testing the battery under load (which was what usbseawolf2000 did)?
It take a high load at low SoC, which the car doesn't really allow for. Consider the extreme case, where you have 11 good cells and 1 dead cell in your block. The 11 good ones can be kept in a higher/wider SoC range by the battery computer, maybe 40-95 instead of 40-80. This is why the battery fan comes on a lot for cars with impending failure, because things really start to heat up approaching 100% SoC in NiMH chemistry. Also why I suggest replacing both pairs in a failed block. If the cell is actually dead, once the surface charge dissipates, you'll see the 1.2V difference if it sits overnight. Now consider a cell that is slightly weak. It may experience a SoC range of 30-90 while other cells are at 40-80. There is no heating, and no significant difference in surface charge effects. But since the weak cell is less able to hold a charge, it will have a slightly higher rate of self-discharge. I think this is one of the failure modes, where a particular cell becomes relatively weaker over time because it experiences a wider SoC range, until it is overcharging and/or reversing. This may or may not show up as increasing internal resistance. I hope that USB does not have a battery failure ever, but if he does, he will have some interesting data. It's all theory, since we can't measure the SoC of individual cells. But letting a reconditioned module sit for at least a week to verify normal self-discharge is definitely part of the overall rebuilding process.
Next time I go on a week vacation, I'll capture the V and IR before and after. It'll be interesting to find out the result.
