Beating the Power Crunch

Electrical demands are a major concern with law enforcement vehicles. This was true with early police vehicles when lighting, electro-mechanical "growler" sirens, and two-way radios severely taxed automotive electrical systems, and it's true today when high-tech lightbars, mobile data terminals, video cameras, and other power-hungry gadgets have become standard equipment.

Electrical demands are a major concern with law enforcement vehicles. This was true with early police vehicles when lighting, electro-mechanical "growler" sirens, and two-way radios severely taxed automotive electrical systems, and it's true today when high-tech lightbars, mobile data terminals, video cameras, and other power-hungry gadgets have become standard equipment.

The law enforcement vehicles of yesterday had 6-volt electrical systems that were tasked with operating growler sirens, incandescent light systems, and radio equipment that operated by vacuum tubes. All of this equipment consumed huge amounts of energy. So departments installed oversized batteries and generators to handle the load. This worked pretty well, but you had to keep the engine running when using the equipment, or a dead battery would leave you stranded. All that excessive idling accelerated wear on the engine and it consumed a lot of fuel.

As police cars and police equipment improved, so did police vehicle electrical systems. Technical improvements-12-volt electrical systems, the A.C. generator, or alternator provided more charging capacity where it was sorely needed-at idle and low speeds. Later, solid-state components-the transistor and integrated circuits allowed electrical equipment to become smaller, consume less space, require less current, and operate cooler, all with greater reliability.


But technological advances and the demands of contemporary policing have forced us to place a multitude of equipment into our law enforcement vehicles, and even though this equipment may consume less overall current than the old tube-type two-way radio and "growler" siren, electrical load issues are still a concern in police vehicles.

Today's vehicles require computer management of key systems, so much so that some cars are equipped with three computers, controlling ignition, fuel injection, transmission shifting, and a host of other functions. The rub is that these computers, along with other accessories such as the AM/FM radio memory, draw power, even when the vehicle is shut off. That's true even for a civilian car. Add the demands of law enforcement equipment-lights, radar, radios, computer equipment, all of which may draw power when the car is off-and the power drain becomes even more acute. With these power hogs on board, all you have to do is let a car sit unused for a couple of days and the battery will be dead.

Light Drain

Other concerns are the high current drain that police lighting and communicating equipment consume while operating-especially lighting equipment.

There have been many advances in lighting equipment over the past 20 years. Both halogen and strobe lighting allow for brighter lights while consuming less current. But perhaps the most promising recent advance in police lighting is light-emitting diode (LED) technology. State-of-the-art LED lightbars consume about 8 amps as compared to 40 to 50 amps for a conventional halogen lightbar.

Generating an adequate amount of current has always been a concern with police vehicles. It remains so today. For example, the 2003 Dodge Intrepid has the highest capacity stock alternator at 160 amps, the Ford Crown Victoria Police Interceptor has a 135-amp unit, and the Chevrolet Impala develops 125 amps. Additionally, there are aftermarket suppliers that supply replacement alternators with up to 200-amp capacity.


There are some devices on the market that sense the battery's voltage and disconnect it before voltage drops below the point where the engine cannot be started.

Another popular solution to the power crunch is the dual battery system. In this system, the lightbar, spotlights, and computer equipment are tapped off the second battery, which is mounted in a marine battery box in the trunk. An isolator allows the vehicle's alternator to charge both batteries. Yet with the engine off, the vehicle's primary battery is not drained by the police equipment and is available to start the engine.

There are several advantages to this system. Battery life is extended and unnecessary idling is eliminated. This will not only save fuel costs, but vehicle components-engines, transmissions, and related accessories-will last longer.

Another short-term solution to the energy demands of modern police equipment is to integrate the necessary devices into one system. Vendors and agencies are looking at ways to combine various equipment items and applications, such as videocamera displays, computer-aided dispatch, and wireless reporting into one video display to reduce redundancy of equipment, increase usable vehicle interior space, and consume less power.

More Power

Of course, even if such integrated systems become standard equipment on police cars, it's likely that more new equipment will be added in the future that will be as draining on power systems as anything we have now. That's why automakers are looking for ways to boost the power of their cars' electrical systems.

One of the innovations that may soon reach the marketplace from this research is higher capacity liquid-cooled alternators. And a little further down the road we will probably see 42-volt systems. Both Toyota and BMW have models with 42-volt systems; however, they are not sold in the United States at this time.

Higher capacity electrical systems will be critical if ongoing research into camless engines bear fruit. Camless engines use electro-hydraulic microprocessors to operate the intake and exhaust valves, rather than a conventional camshaft. A camless engine will have fewer moving parts and engineers will be able to take a smaller engine and tune it to provide maximum fuel-efficiency, output and torque, yet produce minimal emissions. However, because camless engines are electrically controlled, cars equipped with these state-of-the-art power plants will need higher-capacity electrical system.

There are numerous hurdles to overcome before you will see 42-volt electrical systems in production cars, and the technology is some years down the road. So till then, you'll have to make do with your 12-volt systems for a few years more.

Intrepids Made to Order

DaimlerChrysler and Canfield Equipment Services have joined forces in a unique program that delivers custom-made police cars directly to dealerships.

Through the new Intrepid Police Program, you can go to a Dodge dealership, order one of three packages offered-plus any customization needed, and cars will be made to your department's specifications and delivered to the dealership. You won't have to take the cars to a local "upfitter" for police modifications if you don't want to.

Manager of fleet engineering for DaimlerChrysler Gerry Appie says, "We build police cars 100 percent of the time the plant is building cars. So if a department has an accident or something like that where they need cars very quickly, we can build the car and get it through Canfield for upfitting without a long wait period."

The transfer preparation package-the most basic of the three available-allows you to order brand new Intrepids fitted with the wiring and mountings needed to affix equipment from retired cars.

The surveillance package creates a car that looks stock from the outside but comes with essentials such as police lighting that's difficult to detect until it's turned on.

The patrol car package completely outfits a cruiser. Equipment includes a lightbar, a deck strobe in the rear window of the car, and various items necessary in patrol cars.

Police program manager at Canfield Equipment Services Lee Calkins says , "With the surveillance or patrol car package, when the department receives the vehicle, all they have to do is add their police radios and it's ready to go to work."

For more information, contact DaimlerChrysler at (800) 999-FLEET,; or Canfield Equipment at 800-637-3956,

Preserving Battery Life

The modern automotive battery bears only passing resemblance to that old Sears model on your Dad's beloved '65 Mustang. Back then, all you had to do if that trusty DieHard lost its charge was give the car a good push downhill, pop the clutch in second gear, and drive it long enough for the alternator to perform an electrical transfusion.

Car batteries don't work like that anymore. Today, when a car battery drains completely, it  loses much of its lifespan in the process. And if your agency is as cost-conscious as most these days, you don't have a lot of spare cash lying around that you want to spend on replacing dead batteries in your patrol cars.

Only one problem: all that power-hungry gear in your favorite patrol car can drain the battery by drawing on the system even when the car is off. Fortunately, where there's a problem, there's often a solution. And the solution to battery drain in your agency's vehicles may be what automotive specialists call a "smart device."

Smart devices monitor the charge of a car battery when the engine is off. When the battery's discharge level begins to approach the zone where it will no longer provide enough juice to turn over, the smart device electrically "disconnects" the battery by breaking its circuit with the car's electrical system, preserving enough energy to start the car.

One of the most popular smart devices in use by police departments is the Pro Series PriorityStart from BLI International. The Priority Start is a patented smart device that hooks up to the battery with three simple connections..

Larry Hayslett, president of BLI International, says the PriorityStart is a critical piece of equipment for the modern police car because it protects the battery from the drain of  computers, radios, siren and lightbar controls, video cameras, flashlight chargers, and other accessories that are always live, as well as short circuits.

Once PriorityStart interrupts the circuit and protects enough battery charge to start the car. All the driver has to do to reestablish the battery connection is turn on the lights or step on the brakes.

Safeguards are built into PriorityStart to prevent it from disconnecting the battery while the vehicle is running. Even if the alternator belt breaks and the battery drains below the PriorityStart disconnect threshhold, the device's "engine run" feature senses that the engine is on and will not disconnect the battery.

Pro Series PriorityStart sells to law enforcement agencies for about the price of a new car battery. Quantity discounts are available.

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