Do hybrid car batteries go bad?

I know from experience that after a while, my laptop battery stops holding a charge. My car battery stops working after about 5 years. Even my rechargeable AA batteries eventually go bad.

I would imagine the batteries in an electric car are costly to service or replace. Do they go bad at a rate that outweigh the benefits of improved fuel economy?

I test drove a Toyota Prius today. The salesman told me that the battery has an 8-year warranty, and is designed to last at least as long as the engine.

I don’t think hybrids have been out long enough to have an accurate assessment of the battery life under real world conditions. The manufacturers claim that the batteries will last as long as the car, but then they only give something like an 8 year 80k mile warranty on them. If they were so sure the batteries would last the life of the car they’d give them a lifetime warranty now wouldn’t they?

A co-worker recently bought a hybrid. After doing the math he says that overall the extra costs are greater than the fuel saved, but he’s glad he did it anyway because it’s better for the environment.

As engineer_comp_geek suggested, hybrids haven’t really been around long enough for us to really know yet. It’s getting near onto eight years since they were first introduced, if not beyond that (in Japan, not the United States), and so far there’s not really any word on long-term life yet. I’m pretty confident that the batteries will easily outlast the warranty by a healthy year or two, at least (and so is Toyota, or they would be offering a shorter one!). NiMH batteries are wonderful, wonderful things - lighter, longer lasting and able to hold a better charge than SLA or NiCads. My family has two Prius hybrids (IMHO, very much superior to the available Honda hybrids), a first generation and a second generation model, and we love them both. I wouldn’t expect a Prius to be a working “classic” model fifty years from now, but for the normal driveable lifetime of the car, you’re probably in good shape.

That’s not that much shorter than the standard powertrain warranty of 10 years/100k miles. It seems pretty reasonable to me.

If the hybrid owner is lucky, the battery with expire before the warranty does. It’s a safe bet that the replacement price will be pretty stiff.

Maybe by then, we’ll have those miracle batteries Popular Science promised us fifteen years ago. Let’s hope so.

I read somewhere that replacement batteries for hybrids cost over a thousand dollars! So, hope like hell that the battery does give out while still under warranty.

Fisrt, not that the warrantee is 10 years / 150,000 miles in California and some other states. (and its the exact same car)

Here is the official ine from Toyota:

The Prius battery (and the battery-power management system) has been designed to maximize battery life. In part this is done by keeping the battery at an optimum charge level - never fully draining it and never fully recharging it. As a result, the Prius battery leads a pretty easy life. We have lab data showing the equivalent of 180,000 miles with no deterioration and expect it to last the life of the vehicle. We also expect battery technology to continue to improve: the second-generation model battery is 15% smaller, 25% lighter, and has 35% more specific power than the first. This is true of price as well. Between the 2003 and 2004 models, service battery costs came down 36% and we expect them to continue to drop so that by the time replacements may be needed it won’t be a much of an issue. Since the car went on sale in 2000, Toyota has not replaced a single battery for wear and tear.

A pre-2004 (not as good battery pack) Prius taxi went > 200,000 miles without problem.

I’ve heard lots of guesses for replacemnet price. (from 1 to 8 thousand). All I know for sure is thae price is dropping and will keep dropping.


IIRC NiCd’s have a great advantage over Nimh as to the number of charge-recharge cycles, though have the voltage depression issue and memory effects far more then Nimh.

I’ve always thought it would be a good idea to make a hybrid battery pack where a NiCd battery is fully depleted 1st, then moving on to other battery types.

Has he taken the environmental cost of replacement batteries into account? (You’ve got to build new ones and dispose of the old ones.)

An 8-year battery life represents about 50-60% of the ultimate lifetime of a typical car. You need to figure on replacing either the batteries or the car. Each of these has significant dollar and environmental costs.

Tho NiMH is reasonably easy to recycle.
From my cite above:
Is there a recycling plan in place for nickel-metal hydride batteries?

Toyota has a comprehensive battery recycling program in place and has been recycling nickel-metal hydride batteries since the RAV4 Electric Vehicle was introduced in 1998. Every part of the battery, from the precious metals to the plastic, plates, steel case and the wiring, is recycled. To ensure that batteries come back to Toyota, each battery has a phone number on it to call for recycling information and dealers are paid a $200 “bounty” for each battery.

Is there good data for how long typical cars stay in service? I mean there some model A’s around, but there are also a lot of ~10 year old cars in the junkyard.


I drive a Honda hybrid (liked it better than the Prius, personally). My calculations agree that it will cost me more over a 10-year period than buying a gas-only machine. I factored in a $1500 charge for battery replacement at 8 years and kept the price of gasoline reasonably flat. I, too, felt okay about paying for the environmental benefits, particularly the long-term benefits of fostering the market for alternatives to the gas-guzzling status-quo.

The difference is pretty minimal, though, so I may break even if gas prices continue to soar. If I had taken out a 5-year loan, though, the numbers would be worse for the hybrid. Interest charges kill over time.

As for teh battery relacement, it isn’t much different from what I used to fifure for replacing C-V joints on a front-wheel drive manual transmission. (given inflation).

Almost forgot – the financial calculation should figure in the tax break as well. In 2003 that was a $2000 deduction or ~ $630 marginal benefit.

Sounds to me like a shocking price for CV joints. I replaced these on my VW golf for about $110.

Last time I did it (~ 1988, I think) it cost about $600 all told. (Though there may have been other maintenance included – it’s been a long time since I paid that bill.)