Adding water to a battery is not like adding gasoline to an engine. It's more complicated and has the potential to kill the industrial vehicle—or at least the power source—if not done correctly.
It's tough to talk about battery maintenance without getting into the science of these complicated electro-chemical beasts. Properly maintained, industrial batteries are cost-effective workhorses that should last as long as five years. Electrolyte level in a battery rises and falls—much like the tides—in response to the state of its charge. If a battery is overfilled, then charged, electrolyte will rise to dangerous levels. Batteries on chargers produce hydrogen and oxygen gases as a byproduct of the electrolysis process. For overfilled batteries, explosions can happen, along with acid spray.
"When you're using the battery," explains Harold Vanasse, senior vice president, Philadelphia Scientific (Philadelphia), a battery accessory and component supplier, "the electrolyte level is at its lowest because acid has moved into the plates. As you charge the battery, gas is produced on the plates and drives the acid out, causing the electrolyte level to slowly rise."
The message here is to not to fill a battery to the top. When a battery is put on the charger, the expanding acid-laden water can overflow. The industry term is "boil over." Boil over puts sulfuric acid onto the case of the battery as well as the lift truck, floors, racks and people if they are near by.
"The other thing about boil over that's important to know," says Vanasse, "is that some of the sulfates are washed out each time there is boil over. You need sulfates to maintain the capacity of the battery."
Vanasse estimates that for every boil over, the battery loses three percent of its capacity. Those boil overs can add up and impact the running time of the battery.
Battery maintenance experts recom-mend watering batteries on a fixed schedule, depending on the age of the battery. Watering is done typically once a week. The key is to monitor the electrolyte level. It's still not uncommon to find companies filling the batteries when they remember to do it—in spite of what all the battery manufacturers tell them. Hand-watering procedures in some plants (an estimated 70% of the batteries are filled by hand), might consist of an employee with a flashlight looking at water levels, then replenishing with water from a hose or a soda bottle, says Vanasse.
Ingram Book Company (headquartered in Nashville), is a case in point.
"In the past, operators had to check their batteries constantly to ensure appropriate water levels were maintained to prevent dry cells," says Herman Ziebarth, maintenance manager at the company's Roseburg, Ore., facility. "If they found a battery needed water, they had to fill an 18-cell battery one cell at a time using a one gallon jug. It used to take 15 to 20 minutes to change and water a single battery."
Ziebarth is responsible for ensuring that every area of the 350,000 sq.-ft. plant has the supplies and machinery required to keep operations running smoothly, including all rolling stock, conveyor systems and interior and exterior maintenance and equipment, including the lift trucks.
Lift trucks are used throughout the plant, including receiving, shipping, stocking, order processing and quality control. Fifty employees operate the facility's 30 lift trucks, which require approximately 50 batteries, including backups. The lift trucks are used 24 hours per day, four days per week and an additional 18 hours two days per week.
Prior to 2005, Ingram workers individually hand watered each battery using one-gallon, spill-proof jugs. Operators had to don safety goggles, aprons and gloves to protect against battery acid spillage or splashing during the watering process. This system was dangerous due to possible battery acid spills. In addition to safety concerns, watering by hand was also extremely time consuming.
"Depending on the intensity of work," says Ziebarth, "our batteries usually get six to eight hours of use before they need recharging, so they generally need watering once per week."
Managers in the distribution center realized the battery watering system was inefficient. C&D Technologies (Blue Bell, Pa.), one of Ingram's battery vendors, told Ziebarth about a single-point battery watering system manufactured by Philadelphia Scientific. It provided Zeibarth two of the devices for testing. Ziebarth says, "We were so pleased with the results of those two strings that we decided to order the system for our entire battery fleet."
How it works
When a battery needs charging, the operator either replaces the battery with a spare, or docks the vehicle in a centralized charger, replenishing the power while it is still in the truck. In either case, water levels need to be checked, formerly a time-consuming task.
The single-point battery watering system has water injectors that snap onto each battery cell. They are connected to one another with corrosion-resistant plastic tubing. Each injector has its own level-sensing valve, which is powered by water pressure. There are no floats or exposed parts to stick or break.
To fill the batteries, a hose is attached to the input fitting and a ball valve is opened. The water flows through the plastic tubing and, simultaneously, into each of the cells. Within 15 seconds, the battery is filled with each cell receiving the precise amount of water needed.
In addition to accurate and fast watering, the system features a battery-watering monitor. Attached to each battery, the monitor emits a slow, steady, bright green light when water levels are acceptable, changing from green to red when the battery needs water.
If a lift truck operator is in the middle of a run and the monitor light changes color, he knows immediately that the cell needs water, avoiding the risk of running on a dry cell and preventing battery damage.
Ziebarth estimates using the single-point battery watering system has saved Ingram hundreds of hours in manual labor. "Now, one maintenance worker checks every battery in the morning," says Ziebarth. "It only takes about 10 minutes to check an entire fleet. In the past it would have taken more than an hour."
When the battery watering system was installed, Ingram estimated it would take 19 months to pay for itself. The company estimates the ROI took less than 10 months.
A little education
It's no secret that lift trucks are expensive. Batteries and chargers are expensive. So why does a simple, low-cost thing like proper watering present such a challenge? Vanasse thinks it's a mindset that says, "It's just a battery."
A good maintenance program begins with a thorough understanding by management of how much time is spent watering and maintaining batteries, and what kind of life (running time) the company is getting from its battery fleet. Manufacturers of watering systems typically have ROI indicators on their Web sites that can calculate ROI after the size of a fleet, how much time is currently spent watering, and the labor burden, are put into the boxes.
Proper maintenance won't create more running time. There's still no way to get more than the design capabilities of a battery. What does happen is that the maximum yield, in terms of run time and life, is more likely to be achieved.
At Ingram Books, batteries are removed from lift trucks and placed in charging/watering stations. Batteries requiring water are indicated by a blinking light on top of each battery cell.
The single-point battery watering system has water injectors that snap onto each battery cell. They are connected to one another with, corrosion-resistant plastic tubing and a water input fitting. Each injector has its own level-sensing valve, which is powered by water pressure.