The Times They Are A Changing – The End Of The Era of Hybrid NiCd Batteries?
[ad]
When most people read about hybrid cars, and hybrid car batteries, they don’t pay much attention to the technical details.
A hybrid car, as a brief refresher, has a battery that stores electricity (much like a conventional car does for running the alternator, for example). It also powers an electric drive train; the car’s gasoline engine tops off the battery before moving the wheels, and when the car breaks, regenerative breaking refills the hybrid car batteries.
What makes hybrid car batteries work, and what makes them economical, are two different calculations. A hybrid car battery has to hold a certain amount of electrical charge per unit volume. The most common batteries for hybrid vehicles are hybrid NiCd batteries – a NiCd battery is a Nickel-Cadmium battery, and, until the early ’90s, was the best compromise between price and energy density.
The other part of the calculation is how much the battery costs. As mentioned above, a hybrid NiCd battery was one of the best compromises between energy storage density and price; there were (and are) batteries that store more, but when you have to put $400,000 worth of zinc and silver into the battery, it’s not worth putting into a car.
What’s changed is the Lithium Ion and Lithium Polymer battery types. Lithium Ion batteries are about 4-5x the price per watt-hour stored, but they store nearly4x the amount of energy per unit of volume and mass. (They are, in fact, energy dense enough that they can burst into flame in certain applications, something that NiCds can’t do.) Lithium Polymer batteries are just entering the market for hybrid vehicles; they’re roughly the same energy density as Lithium Ion batteries, but are lighter overall (reducing vehicle weight and increasing range and acceleration), and are marginally less expensive to manufacture.
Where hybrid NiCd batteries come into the news is replacing them and disposing of them. Nickel Cadmium batteries have, as the name states, cadmium in them. Cadmium is a heavy metal and considered a dangerous pollutant by most of the industrial world, so they take special care in disassembly and recycling, an expense that many hybrid car owners aren’t aware of when their car reaches its end of life phase.
Fortunately, only the oldest of the hybrid vehicles were released to market with hybrid NiCd batteries. Most cars from 2002 onwards used Nickel Metal Hydrides (or NiMH) batteries, which are more efficient, less expensive, and MUCH easier to dispose of. (While nickel is also a heavy metal, and in many ways as toxic as cadmium, the regulations for it are much more lenient.)
If you’re planning on replacing your hybrid car battery, take the time to calculate how many miles you drove in the last year, and work out a cost-benefit analysis. Also factor in the type of driving you did; it probably makes sense to replace the hybrid car battery rather than selling the car for parts, but this is by no means a guaranteed thing. On the other hand, cars have a sentimental attachment value that goes beyond cost-benefit. There is a certain amount of “geek appeal” to having the only Prius in your neighborhood with top of the line lithium ion batteries, assuming you can find a place that can handle the replacement and installation.
Recommended Reading
More Information on Green Living
- Convert Any Car to Electric — "All the steps are numbered with diagrams to be easy to follow. The conversion does not take too long, all you have to do is follow the simple plans I provide and in a month, you will cut your gas bill to zero."
- Renewable Energy Solutions — "Family living off the grid with renewable energy takes know how and applies it to solar panels and wind generators."
- Build A Wind Generator — "For the past 15 years our family has been living off the grid with only solar and wind power. We moved to our present location, built our own house ourselves and set to work to find alternative energy options for our home that we could afford."