Government Takes on Hybrid Reliability

For about 10 years, the long-term reliability of hybrid-electric vehicles has remained relatively unknown and constantly in question, even though current hybrids’ track records and reliability ratings are positive. People fear having to replace a hybrid’s expensive battery pack, and are generally concerned about high-dollar repairs because of the advanced technology in hybrids. Surprisingly, these concerns have been directly confronted by the U.S. government.

Since about 2001, the U.S. Department of Energy’s Advanced Vehicle Testing Activity department has conducted accelerated reliability tests on hybrids to address such concerns. AVTA’s tests are primarily for fleet operations, where vehicles rack up absurd amounts of miles in a short period of time. The vehicles tested see mileage numbers up to 50,000 miles per year and remain in service until they hit 160,000 miles. The information collected still holds value for the average 15,000-mile-per-year car shopper, however. Data such as fuel economy, maintenance and repair costs are meticulously recorded throughout the vehicle’s term, and every factory-recommended maintenance procedure is followed. The test results are available to anyone and can be viewed at AVTA’s website.

At the end of 160,000 miles, hybrids are tested for fuel efficiency and remaining battery pack capacity. This would be roughly equivalent to a normal driver driving 16,000 miles a year for 10 years. Again, though, the test vehicles are put through extremes. The end-of-life battery tests were performed on the first-generation 2002 Toyota Prius, 2001 Honda Insight and 2003 Civic Hybrid, not current models. Two examples of each model were tested: The Insight hybrids drove away with 85% battery life, the Civics had 68% life and the Prius models had 39%. For the complete evaluation, go here.

So it seems those worries about having to replace a hybrid's expensive battery before the 10-year mark have been somewhat alleviated.

AVTA still has hybrids in service with courier fleets and high-mileage commuters in various commercial and governmental organizations. It’s common for two or more of the same model to be tested simultaneously. As of February 2008, the hybrids being tested or having already completed testing include:

• 2000-01 Honda Insight
• 2001-02 Toyota Prius
• 2003 Honda Civic Hybrid
• 2004 Chevrolet Silverado Hybrid
• 2004 Toyota Prius
• 2005 Ford Escape Hybrid
• 2005 Honda Accord Hybrid
• 2006 Honda Civic Hybrid
• 2006 Lexus RX 400h
• 2006 Toyota Highlander Hybrid
• 2007 Saturn Vue Green Line
• 2007 Toyota Camry Hybrid
• 2008 Chevrolet Tahoe Hybrid

After scouring through the data, we’ve found that examples of hybrid-related problems range from a failed battery pack connector and even total battery pack failure. The Ford Escape Hybrid suffered from a battery pack connector that failed at 59,883 miles and was replaced for $250. A 2004 Silverado Hybrid’s electric motor stator failed at 90,123 miles, and another Silverado’s battery pack failed at 35,867 miles; both items were repaired under warranty.

The information is valuable, but remember that these cars are put under extreme heavy-use mileage conditions, and only in Arizona. Someone driving the same car in Illinois or New York accumulating only 10,000 miles a year will almost certainly see different results.

Comments

[Tony]

These tests are still better then no tests but results of these tests still do not show the whole picture of 10 year use of the car.
The car will age even if not used. The materials go through cycles of expanding and contracting. Especially during the winter, and especially if you live in climats with cold winter. This is why testing a car in 3 years and driving 150 miles per day is different then natural aging process of the car.

[HybridPlugs.com]

I think the point here is that Hybrid batteries are not and issue. Also these reports are on early Hybrid models and the newer ones are even better.
Tony, your right 10 years real time would be a more accurate measure of materials, but at least we now have a report to help people who were put off by fake stories of how expensive replacing the battery would be in these cars.
They are good cars, they work.

[Bob Wilson]

Some of us have already been investigating how to refurbish these batteries using the method described in patent 6,936,371. It turns out that the loss of water from the electrolyte can be restored and the batteries returned to like new status. Click on my name below and the URL shows my latest experiment. Hybrid batteries are too precious to waste and loss of a few cents of water is no excuse for replacement.