In the wake of President Obama’s fuel efficiency standards for medium and heavy duty vehicles, truck fleets are facing increased pressure to find technologies that can maximize both vehicle efficiency and reliability.
One such innovation is ultracapacitors. Also called supercapacitors, they are power storage devices that improve starting reliability while at the same time help reduce idle time in trucks.
Able to work alone or as complements to batteries across a spectrum of applications, ultracapacitors take over the cranking and starting function from lead-acid batteries, thereby leaving the batteries free to power energy-intensive loads such as sleepers and lift gates.
While batteries have a high energy storage capacity and perform well as continuous sources of low power, ultracapacitors excel in responding to peak power demands.
Since they charge and discharge quickly, ultracapacitors can deliver quick bursts of power when needed. These abilities make ultracapacitors ideal supplements to a primary energy source, such as the battery bank in trucks.
DISCHARGED BATTERIES
When batteries are partially or fully discharged, they cannot provide enough power to crank the engine.
There are many contributing factors that cause discharged batteries, including:
- Excessive loads.
- Weekend or seasonal inactivity.
- Frequent stops and starts.
- Overuse of the liftgate with the engine powered off.
Because they can provide 100 percent of the cranking power, ultracapacitors can mitigate the issue of costly jump-starts by providing the necessary power to start the truck engine, even when batteries have been seriously discharged by these common trucking issues.
IDLING
Because dead or discharged batteries and the subsequent jump-starting process cost valuable time and money, many truckers choose to idle their diesel engines for long periods of time instead of risking failure to start. This is particularly the case when the temperature drops below freezing.
Not only does idling damage the environment, it also wastes fuel. The Argonne National Laboratory report, Estimation of Fuel Use by Idling Commercial Trucks, estimates that an average heavy duty truck burns about one gallon of diesel fuel per hour when idling.
The report goes on to say that more than 650,000 long-haul heavy duty trucks idle during rest stops, resulting in 685 million gallons of fuel and more than $2 billion wasted annually.
Mark Burnside is the senior product manager of engine starting at Maxwell Technologies (www.maxwell.com), a company that develops and manufactures innovative, cost-effective energy storage and power delivery solutions.
