Cliff Burwell of Northridge, California-based Dayni Controls, knows the controller market well. His company is one that specializes in manufacturing battery-powered controllers. "If you have trouble getting power, the battery is the way to go," says Burwell. "Depending on the site, like where lightning is common or power outages are a problem, there are many more advantages to a battery controller compared to an electrical system."
In addressing the difference between battery and electrical power, the main concern is with the power supply. The controller and solenoid each need electric current to operate (controlling water output and timing), whether from a battery or electric source. The efficiency of the power supply determines whether or not to use battery power.
Submersion is another factor to address when choosing controllers. In the past, submersion was a problem with battery-powered units. "The electronics weren't waterproof," explains Heenan. "It's only been in the past three to five years that a few companies have come up with the technology that protects the electronics."
In terms of current draw, the latching solenoid requires a significant amount of energy. For a battery-powered supply, this normally limits the valve box controller to operate only one valve at a time, but at a short distance.
George Alexanian, president of Alex-Tronix Controls, a pioneer company in the development of battery and other specialty controls for over 20 years, says that greater distances of valve operation are a must — especially for the commercial unit with multiple stations.
Valve operation at longer distance expands the use of battery controls for specification agencies and the commercial end-user. Through new and patented technology owned by Alex-Tronix, the problems of power for long distance and extended battery life have been eliminated.Energy allocation is the key difference with the operating distance issue. With an electric controller, a constant flow of electricity is supplied to the solenoid, keeping the valves operating as needed. A battery sends surges to the solenoid as needed to open and again to close, to conserve energy and prolong battery life. Otherwise, a battery's life would be drastically shortened — the normal life span of battery-powered controllers is estimated at 1,000 valve cycles, or about one year. With this new technology, the life span has been increased to 10 times that amount.
Attempts have been made to combat this problem by using low-power latching solenoids, but hydraulic performance is limited, which is discussed below. Solar panels are also an option to maintaining and restoring a battery pack's life. While these panels are efficient at combating battery life, they do not address the longer distance issue and are subject to damage and vandalism, and can only restore energy capacitors in sunny or ambient light. The solar panel option also raises the price tag of these controllers substantially.
Another question raised about the amount of juice needed to run one or multiple stations hinges on the reliability of latching solenoids. To address the aforementioned issue of valve operating distance, technological advancements have created low-power latching solenoids. These types of solenoids conserve energy, but at a cost — low magnetic force sometimes fails to adjust to adverse conditions like high water pressure and low battery voltage. Because of this, reliability of these types of solenoids may result in sub-par performance..
An age-old problem with battery controls is the compatibility question. Most battery-operated controllers are designed to operate a particular latching solenoid. While there are adapters available to interface from certain latching solenoids to other valves, most controllers can only operate a limited number of solenoids. All aspects of compatibility should be considered when specifying or using any battery-powered controller.
So why go battery, you may ask?
When you do not have power or it's too expensive to get, there are many benefits to a wireless controller:
New digital display screens are available, making it easy for the user to follow step-by-step programming icons.
With every system there are setbacks and room for improvement. Battery-powered controllers are no different. The future is bright in the battery-powered controller arena, as technological improvements surround their manufacturing each year. Most of the downsides to battery usage will undoubtedly be addressed in the near future, allowing all types of controllers to maximize their potential and usefulness.
"There's room for everybody in this industry, battery and electric," says Burwell. "However, when getting electricity to the controller is not feasible, battery's the way to go."
Heenan concurs: "I've been selling battery controllers for 18 years now — the good ones and the bad ones. I can say that the reliability and performance has improved drastically. Contractors need to take a second look at battery controllers, and not just for remote areas."
Alexanian agrees that battery-powered controllers have improved significantly in recent years. He says, "We have addressed all four major concerns of distance, battery life, compatibility and reliability, and have been successful." This accomplishment, along with future research and development, will yield even more interest, confidence and use of battery-operated units.