A hundred-dollar adjustment to city police cars may allow them to nearly double their gas mileage.
The Crown Victorias, which now average 8 mpg because police idle them between patrols, could get up to 15 mpg in the city if police turn them off during lengthy stops.
For two years, police have been trying to adjust their engines so they could turn off their cars. Now, they appear to have finally solved the problem.
Timers now turn off almost all of the equipment in the car before it drains the battery during stops. Only the video camera is left running.
“That’s one thing we never put on a timer. We don’t want the camera turned off,” said Lt. James Sanders, who has overseen the work.
The cameras are intended to record arrests and interaction with the public, to both bolster criminal cases and to provide neutral evidence in accusations of police misconduct.
But even with the timers, the cars that were turned off often stalled this winter.
“It’s just the colder weather that causes a problem,” Sanders said.
Car batteries are less powerful in the winter, and the timers just weren’t inhibiting the electronics enough to keep from using up the little available power. So the department bought three voltage monitors that gently cut power to the battery when electronics were about to drain it.
The Priority Start voltage monitors cost $100 apiece, so Sanders wanted to try them out before buying 25 of them to outfit all of the patrol cars.
“It definitely does the trick,” he said after experimenting with three cars for two months. “It definitely seemed to resolve those issues. I’m pretty sure we can cover [22 more monitors] with confiscated money.”
He’s not sure whether the city will see a significant increase in gas mileage, but the Energy Advisory Board reported last summer that the Crown Vics could get 15 mpg if police could turn off their cars.
At the time, board members were assured that it was impossible. There are just too many electronics drawing on the battery, Public Safety Commissioner Wayne Bennett said.
Police car batteries die so often that supervisors keep battery-jump packs in their vehicles and at the station. Often, cars parked at headquarters have to be jumped before officers can leave.
But Sanders said the new devices make it safe to turn off the car any time. It’s the culmination of three years of work.
“We’ve been thinking about this for years,” he said. “It seems the last two to three years we’ve really gotten a lot of technology in the cars. We even thought about putting dual batteries in the car.”
They even tried solar panels.
The SWAT van, which is used only every few weeks, was so often found with a dead battery that police put a solar panel on the dashboard.
“It plugs into the cigarette lighter,” Sanders said. “Now it can be the coldest day in the world and it will trickle-charge so the battery can start.”
But it was hardly realistic to put solar panels on cars that are used nearly 24 hours a day. On those cars, police switched to a low-riding light bar, which cuts wind resistance somewhat and uses far less battery power. The old-style lights used so much power that the car would die if the engine was turned off for just 20 minutes, Sanders said.
“Now you can let that run probably for over eight hours, and the car starts right up,” he said.
But all the other electronics on board kept draining the battery anyway.
The battery supports a laptop, scanner, printer, radio, sirens, lights, a video camera, the charger for each officer’s microphone, electronic locks for the car’s shotgun, speed radars, the laser charger, a GPS unit and, on some cars, automatic license-plate readers.
“It’s all being provided by one 12-volt battery,” Sanders said.
For now, the $100 voltage-monitor and the equipment timers keep those batteries healthy. But in the long run, Sanders said, the solution will be buying cars designed specifically for police, with all the electronic equipment included. One such car, in development now, is advertised as lasting twice as long as a Crown Vic and getting 28 mpg in the city, as well as providing power for built-in electronics.
“You wouldn’t have all these peripherals, the printers, scanners,” Sanders said. “You know, all those become projectiles in a crash.”