Clear signs usually indicate when a lift truck is about to go down. Fluid leaks, power problems and noisy brakes are among the clues that tell managers it’s time to service the vehicle.
With the batteries that power electric lift trucks, however, it’s a different story. It’s difficult, if not impossible, to see what’s happening under the casing.
“A battery is a mysterious commodity,” says Dennis Beame, president of IntelleFleet (Irvine, Calif.). IntelleFleet supplies wireless fleet management tools for electric lift trucks.
“Batteries are not understood,” adds Harold Vanasse, vice president of sales and marketing for Philadelphia Scientific (Montgomeryville, Pa.), a provider of industrial battery maintenance products. “We often take them for granted and overlook them.”
These days, material handling managers can no longer afford to ignore battery maintenance. The cost of industrial batteries has nearly doubled in recent years due to the rising cost of lead, according to Larry Hayashigawa, director of product management at PosiCharge, a subsidiary of AeroVironment (Monrovia, Calif.) that specializes in fast charging. Proper maintenance protects the battery investment. “Improper battery treatment will reduce battery life by as much as 33%,” says Hayashigawa.
| Managers can download battery data from the PowerTrac SP to a PDA. (Photo courtesy: Exide Technologies) |
Companies that view batteries as assets rather than liabilities realize that proper maintenance will ensure long battery life, extend the life of vehicles, maximize warranty benefits and boost operator productivity.
“For a warranty to be in effect, a customer has to maintain and operate the battery a certain way,” explains Michael Matson, motive power battery product manager for GNB Industrial Power, a division of Exide Technologies (Alpharetta, Ga.). GNB Industrial Power supplies standard and fastcharge batteries. “If these instructions are ignored, the usable battery power and battery life are adversely affected. With proper care, end users will maximize the power they can get from their battery investment.”
However, keeping batteries in top condition is often easier said than done. In a multi-shift operation running several lift trucks, for example, managers are charged with maintaining a large number of batteries. And, battery-room attendants are becoming a thing of the past.
In addition, as manufacturers and distributors throughout North America get lean and leaner still, they are under intense pressure to squeeze cost out of the system. In an effort to ‘get lean,’ many of them have eliminated the pool of extra batteries they used to keep as a safety net. And, keeping fewer batteries means less tolerance for breakdowns. “The heart of lean is no more fluff,” says Bret Aker, CEO of Aker Wade Power Technologies (Charlottesville, Va.), a supplier of fast-charging systems.
Switching to fast charging also results in fewer batteries. In typical fast-charging operations, the battery is charged while it’s in the truck, and there’s usually just one battery per truck. The benefits are reduced labor costs and increased productivity.
“The cost, however, is that you have to watch things more closely,” Aker says. “When you’re down to just one battery, you save money and increase productivity, but you need better information.”
Collecting the Data
That kind of information is available, thanks to sophisticated hardware and software that collects battery data in real time and reports it, often wirelessly. As industrial battery prices rise and the cost of gathering data comes down, many lift truck fleet managers are turning to high-tech, battery-monitoring systems as one way to reign in operating costs and preserve battery life.
“There are several battery-monitoring devices that provide basic or very detailed information, says Ed Miller, product support manager for motive power at East Penn Manufacturing Co. Inc. (Lyon Station, Pa.).
East Penn manufactures Deka brand batteries for fast-charge, opportunity and conventional applications. “This information can include the battery state of charge, temperature, ampere-hours discharged or charged or frequencyof- equalize charge,” Miller says.
For example, PosiCharge’s fast chargers feature the PosiNet asset management system, which extracts data from a battery module and identifier (BMID) installed on the battery. “The system reports on state of charge, temperature, voltage, ampere-hour throughput and plug-in compliance,” Hayashigawa says. “It indicates how many equalization events occurred, if a battery is over temperature or if a charger malfunctions.”
Aker Wade’s fast chargers gather three types of data: status, usage and charge operations. Status refers to temperature and states of charge, while usage information details how much energy was used and whether or not there was excessive time between charges, according to Aker. Charge-operations data confirms batteries were properly equalized.
Both GNB Industrial Power and Crown Battery (Freemont, Ohio), a provider of conventional and fastcharge batteries, use the PowerTrac SP series battery data logger from Power Designers (Madison, Wis.) to monitor battery health on their fast-charge systems.
| IntelleFleet’s CELLect data collector module |
“We use it as a diagnostic tool for warranty analysis, offer it as an option for our GNB, Tubular-HP, Liberator and Element batteries and require its use on our GNB Fusion fast-charge batteries,” says GNB Industrial Power’s Matson. According to Matson, the PowerTrac SP series monitor tracks and logs battery voltage, current and temperature as well as charge and discharge ampere-hours and charge and discharge events. The battery monitor also provides guidance on minimum and maximum voltages and maximum currents and temperatures. The PowerTrac SP also reveals what time the battery was charged or discharged and for how long, according to Paul Booth, technical services manager at Crown Battery.
Electric Transportation Engineering Corp. (eTec) offers the Minit-Charger fast-charge system, which includes a battery interface and charge control (BICC) module that performs two important functions, according to Steve Schey, regional manager at eTec, a subsidiary of ECOtality (Phoenix). “It assesses battery status and controls charger output rates,” he says. “It helps to control the charge that the charger is delivering and also monitors the health of the battery.”
The BICC also keeps track of charge history, or cumulative ampere- hours, which is particularly important for monitoring warranty life, Schey adds. “This measure of how close the battery is getting to the end of its warranty life can be used for battery replacement planning,” he says. The Minit-Charger also has an electrolyte indicator that alerts managers when a battery is under watered.
And, IntelleFleet’s CELLect technology has data collector modules (DCMs) that show run time, charge time, discharge and cool time for every battery in a fleet. “A base station mounted in or near the charging area wirelessly interrogates each DCM 24 hours a day, seven days a week,” says Beame.
Getting the Data
Collecting data is one thing; accessing it is another. Battery and charger manufacturers offer a range of possibilities for viewing and analyzing critical maintenance data.
With PosiCharge’s PosiNet system, users choose from three methods of retrieving data. “With PosiNet Web, customers access information on the Internet,” says Hayashigawa. “We can produce exception reports for service and maintenance, which are broadcasted to an e-mail address,” he explains. “With PosiNet single-point download, they go to a central area in the facility and download the data from a hub.” Hayashigawa explains that the data hub “requests” information from the chargers every few minutes, and then, the charger transfers the data to the hub. Users can later transfer the information to a computer. PosiCharge also offers PosiNet DDA (desktop data analysis). Designed for relatively small lift truck fleets, PosiNet DDA allows users to download data from a single charger.
Aker Wade’s chargers are equipped with wireless, industrial Bluetooth chips that compile and store battery data. With a handheld device or personal computer, users access the data from within 100 meters of each charger.
The PowerTrac SP monitor on GNB Industrial Power’s batteries “uses a conventional current shunt and an infrared data transfer protocol for download to IrDA [Infrared Data Association] ports and PDA devices,” says Matson.
And, finally, IntelleFleet’s CELLect system is entirely Web based. “All data is transferred automatically to database servers, and a customer accesses it online with a user name and password,” says Beame. “When an operator changes a battery, he or she logs in with a user name and password. The system polls the batteries, and on a touch screen, certain batteries are marked green, meaning those are fully charged and rested and have no mechanical defects,” Beame explains.
If a battery is in an over-temperature state, an e-mail or text message is automatically sent to a supervisor. Batteries that are fully charged yet still cooling are marked yellow, while batteries that are still charging are marked red. Operators are instructed to select the green batteries—the ones ready for service.
Acting on Information
Downloaded data, no matter how detailed, isn’t useful without analysis. When it’s applied to make decisions and draw conclusions, data transforms into information.
'“Material handling managers can utilize a great deal of important information from battery-monitoring devices,” Miller says. Information helps identify productive batteries, those in need of maintenance and those that need to be replaced. In addition, Miller says that managers can track battery capacity usage and cycles in a 24-hour period, monitor that the recommended battery rotation system is being followed, determine that there is a sufficient amount of batteries and chargers to support the operation, monitor utilization of battery-powered equipment and schedule and justify battery and charger additions and replacements.
Long-term benefits of batterymaintenance information include increased battery life, lower operating costs and the ability to detect battery, charger or operational concerns and implement corrective action, according to Miller.
Matson adds that battery information can help extend the useful life of equipment, prevent damage to lift trucks and pallet jacks, increase vehicle productivity, lower repair costs and reduce downtime.
Battery-monitoring systems can even save energy, according to Beame, by ensuring that batteries are charged at the right time. “Batteries should operate at 40% to 80% of their rated capacity,” he says. “The average battery utilization by physical run time is less than 40% of available capacity, which means a lot of energy is being returned to the charger prematurely. You can’t recover that energy.”
“Batteries are priced 40% to 50% higher than they have been in the last couple of years,” says Booth. “Preventive maintenance is more important now than ever.”
Finally, information reduces guesswork, allowing managers to get to root causes. “These technologies provide important information for fleets about battery-maintenance issues so they can address them before they become problems,” says Aker.
In short, battery-monitoring systems allow managers to peer under the casing and take some of the mystery out of battery maintenance. As Hayashigawa says, “they put metrics on what has traditionally been a metric-less commodity.”
“Millions of dollars are spent in the U.S. annually on finding the source of problems,” adds Beame. Having this information at the fingertips helps “pinpoint the real source of the problem. It pulls back the veil.”