MRO Today - Battery maintenance

Battery maintenance

Today’s lead-acid batteries are the best ever made, but battery maintenance practices have advanced even further

by Harold Vanasse

Today’s lead-acid batteries, particularly those made since the advent of the cast-on-strap process, are the highest quality products ever for use in forklift trucks. They are more consistently manufactured and more reliable than their predecessors, which were made with less automated manufacturing processes.

Still, there’s evidence that the biggest advances in the last 10 to 20 years have come not in batteries, but in battery maintenance practices. A micro industry now offers a variety of tools to help battery room and warehouse managers extend the lives of their batteries, ensure the highest possible performance, increase worker productivity, improve warehouse safety and be in compliance with OSHA regulations. As a result, forklift managers are increasingly touting their operations’ ROI.

An estimated 70 percent of industrial batteries are still filled by hand, a time consuming task that can be accomplished up to 20 times faster — and more safely — with today’s battery maintenance equipment. Between labor savings, eliminating the hidden costs of over- and under-watering batteries, and the utilization of other maintenance and operating tools, managers of large warehouse operations can save tens of thousands of dollars a year in personnel productivity, equipment maintenance and replacement costs.

Battery watering: A simple job done poorly
There are many tools to help manage battery assets. Properly maintained, industrial batteries should provide five years of reliable power. But one of the simplest battery maintenance tasks is also one of the most poorly performed: battery watering.

Over-watering a battery can create “boil-over,” in which sulfuric acid is spilled onto the surface of the battery, as well as, the lift truck, floors, racks and — potentially — workers. This not only creates a damaging and hazardous condition within the warehouse, but also decreases the battery’s useful life.

Why? During a boil-over, some of the sulfates are washed out of the battery. Sulfates are needed to maintain the capacity of the battery. For every boil-over, the battery loses approximately three percent of its capacity. Over time, boil overs can decrease the life of a battery by six months or more.

Under-watering is another common problem. Under-watering can happen when batteries aren’t watered on schedule or when they are manually watered and the operator accidentally skips a cell. When a cell is skipped in a typical watering regimen, it might not get the water it needs for another week. That can result in permanent damage.

When parts of the battery’s positive and negative plates get dry, battery capacity is decreased. Sulfation develops on the dry part of the plate, and even when water is re-introduced to the dry cell at the next scheduled watering, it will not return to its previous performance. In the worst case, a damaged cell would need to be replaced entirely — an expensive proposition.

The most common culprit: you
The most common factor contributing to over- and under-watering is the hand-watering of batteries. An estimated 70 percent of industrial batteries are filled by hand, despite the fact that single-point battery watering systems have been available for years.

Single-point watering systems offer a cost-effective and safe alternative to hand-watering. There are several such systems available, and for the most part, they operate similarly.

The first single-point systems were manufactured with floats that gauge the electrolyte level. In the early 1990s, Philadelphia Scientific pioneered a pressure-dependent watering system that uses water injectors which are snapped onto each battery cell and are connected to one another with corrosion-resistant plastic tubing. Each injector has its own level-sensing valve, which is powered by water pressure, ensuring precise sensing of electrolyte levels in each cell.

To fill the batteries, a hose is attached to the input fitting and a valve is opened. The water flows through the plastic tubing and, simultaneously into each of the cells. Within 15 to 20 seconds, the battery is filled, with each cell receiving the precise amount of water needed.

Speed watering
Using a single-point watering system, batteries can be filled up to 20 times faster than by hand-watering, increasing worker productivity and improving safety.

In 2006, Philadelphia Scientific surveyed users of its single-point Water Injector System to determine the ROI the systems provided. ROI was determined by considering labor savings from the decreased time spent watering batteries; time saved due to less frequent battery changes during shifts; and savings from less frequent battery purchases as batteries experienced longer life spans with proper maintenance.

Survey results revealed that in a typical 100-battery fleet, a company can expect to save approximately $26,000 per year with an ROI of approximately 13 months.

Get organized
Battery room and warehouse managers can also more effectively manage their battery usage — and therefore, the useful life of their forklift batteries — by organizing and sequencing the use of their batteries.

When fork truck drivers enter a battery room to get a replacement battery, how do they know which battery to take? Normally, chargers have a small light indicating that the battery connected to it had finished charging. But in most battery rooms, there are often several of these lights on at any one time. Which one does the driver pick? Usually, the nearest available battery. That means the batteries nearest the entrance get used more than those at the far end of the room. Sometimes the ones at the end don’t get used at all.

There are several battery organizing systems on the market that can eliminate the uncertainty of battery selection, increasing the useful life of the battery fleet.

One such system works by collecting charger data through electronic monitors. These monitors send data to a central controller, which then processes the data and sends a message to a scrolling LED display informing the forklift driver which battery to take.

If the driver misunderstands or ignores the display’s instruction and selects the wrong battery, a “Shouter” loudspeaker points out the error. The monitors can work with virtually any charger, including high-frequency types.

Battery organizing systems can range dramatically in complexity and cost, but most will pay for themselves within two years, and do so in two ways. First, they improve efficiency by organizing the battery-changing operation in real time to ensure that all batteries are used in strict rotation, preventing battery abuse and related problems down the road.

Second, battery organizing systems improve corporate asset management by diagnosing problems. Many organizing systems collect an enormous amount of data from the chargers, and some are designed to reduce the data to a compact executive summary report. This is extremely valuable for leasing companies, multiple site companies, those operating during peak periods of seasonal activities or any medium to large facility with a hectic schedule.

Easy-to-implement, cost-effective ROI
Warehouse and battery room managers are no different than other business managers; they are all looking for tools to help them run more efficiently and, where possible, demonstrate a healthy ROI to their direct reports. Historically, battery maintenance has not been viewed as an area for improvement. “Hey, they’re just batteries,” a manager might have said.

But today’s arsenal of battery maintenance tools can save large warehouse and distribution operations tens of thousands of dollars per year. Better battery maintenance may be one of the simplest and most cost-effective strategies a manager can implement to demonstrate an impressive ROI.

Harold Vanasse is vice president of sales and marketing for Philadelphia Scientific in Mongomeryville, PA; Web site: www.phlsci.com.

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