Where we are
All five of the battery types discussed here are currently either used in electric vehicles or are planned to be used in those vehicles. Nearly all vehicles use lead acid batteries for starting up, and some of the original experimental electric vehicles used them as well. The most commonly used batteries in hybrids are NiCd in older ones, and NiMH in newer ones. The vehicles coming out in the next few years are likely to use Lithium Ion and most prototype cars use either Hydrogen or Lithium Ion batteries.
Most prototype cars use either Hydrogen or Lithium Ion batteries
Below is a table displaying some key metrics for the current state of the five main types of batteries we have been talking about throughout this section.
| Metric || Importance || Lead Acid || NiCd || NiMH || Lithium Ion || Hydrogen
| Charge/Discharge Efficiency || % of energy entered vs. energy returned || 70-92% || 70-90% || 66% || 99.9% || up to 80%
| Energy to Weight || Amount of energy stored per weight || 30-40 Wh/kg || 40-60 Wh/kg || 30-80 Wh/kg || 160 Wh/kg ||
| Energy to Volume || Amount of energy stored per volume || 60-75 Wh/L || 50-150 Wh/L || 140-300 Wh/L || 270 Wh/L ||
| Self-Discharge Rate || % energy lost over time || 3-20%/month || 10%/month || 30%/month temp. dependent || None in "dumb" batteries, 5-10%/month in "smart" || None
| Lifespan || Number of hours or cycles before battery loses 20% of it's capacity || 500-800 cycles || 2000 cycles || 500-1000 cycles || 1200 cycles or 24-36 months || 5000 hours (150,000 miles)
| Fast Charge Time || Time for a rapid charge || 8 to 16 hours || 1 hour || 2 to 4 hours || 1 hour or less ||
| Energy to Cost || Amount of energy stored per dollar || 7-18 Wh/$ || Unknown || 2.75 Wh/$ || 2.8-5 Wh/$ ||
| Toxicity || Harmfulness of components || Toxic lead and acids but fortunately, about 90% of lead acid car batteries are recycled || Cadmium is highly toxic and harmful to the environment || Relatively low toxicity, should be disposed of properly || Low toxicity || Low to no toxicity
For our sources, click on the the battery technology you are interested in: Lead Acid
, Lithium Ion
For more information on the different battery technologies and where they are in terms of efficiency, power density, cost, toxicity, and lifespan, check out the table at http://www.batteryuniversity.com/partone-3.htm
Environmental Health and Safety Online - Batteries
Facts about battery usage, disposal, recycling, and toxicity.Click now to view
Wikipedia - Lead acid batteries
Wikipedia info on Lead Acid batteriesClick now to view
How Stuff Works - Fuel Cells
Description of how fuel cells, specifically Polymer Exchange Membrane Fuel Cells that are likely to be used in motor vehicles, work.Click now to view
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