Other Voices: Three major impacts on battery room operation and maintenance - #1: Battery rotation

Editor’s Note: The following column by Harold Vanasse, vice president of sales and marketing, Philadelphia Scientific, is part of Modern’s Other Voices column. The series features ideas, opinions and insights from end-users, analysts, systems integrators and OEMs. Click here to learn about submitting a column for consideration.

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In part one of this series, I revealed that six of the eight sources of Lean waste can be found in the battery room. Studies and anecdotal evidence have shown that waste in the battery room can cost large warehouses and DCs hundreds of thousands of dollars per year. Even small operations with as few as 10 to 20 lift trucks can lose tens of thousands of dollars due to these wastes.

To achieve measurable and sustainable elimination of waste, managers need to focus on the three major impacts on battery room operation and maintenance: rotation, right-sizing and battery watering. The second part of my series focuses on battery rotation.

The costs of poor battery rotation
The #1 cause of reduced battery run time, reduced battery life and waste in the battery room is improper battery rotation. This occurs when forklift operators make their own battery selections without proper direction as to the “correct” battery to take. Left to their own devices, operators will take the closest battery (in order to make the quickest change) or the newest battery (in hopes of getting the longest run-time). The “correct” battery – the battery that has had the longest cool down time since charging – may be in the back of the battery room. So, many operators will take the closer battery. Convenience trumps proper rotation.

The consequences of improper battery selection are costly. Site tests have shown that when battery selection is left to an operator, 30% of the batteries will be underutilized and 20% will be overused. The result: uneven battery usage, premature battery failure and lost productivity.

The key to ensuring proper rotation – that is, selecting the battery that has had the longest cool down time since charging – is to make picking the right battery simple and to measure performance for accountability. When proper battery rotation practices are implemented the results are dramatic. In a study of one company’s introduction of good battery rotation practices in which data was collected for the three months before and three months after proper battery rotation procedures were introduced, the average battery run time increased from 6 hours 30 minutes to 6 hours 57 minutes – nearly half an hour. And there is no reason lift truck fleets can’t achieve eight hours of run time from their batteries.

An additional benefit of proper battery rotation is knowing exactly how many batteries the lift truck fleet needs – and avoiding purchasing more batteries than are needed.

Battery management is the key to proper rotation
Battery room management systems are the single most effective tool for ensuring proper battery rotation and, therefore, reducing waste in the battery room. The best systems directly measure the charger to obtain accurate data on the state of charge of each battery. With this information, operator judgment in battery selection is eliminated because the system has determined which battery has had the longest cooling time since charging. Once charged, each battery is placed in queue. A simple-to-use “read and react” display then tells the operator which battery to take.  An audible alarm that alerts the operator when the wrong battery is taken is a smart and useful addition for battery room management systems.

Some systems automatically report state of charge data to the Cloud, where easy-to-understand reports can be generated and made conveniently available using any web browser. The reports provide feedback, a fundamental tenet of the Lean process, and can signal the manager when certain alert conditions are triggered, such as…

1. Availability: Battery usage information that indicates to managers if they have too few or too many batteries.
2. Cool down: Shows how much cool down time the battery fleet is actually obtaining. Remember, hot batteries shorten life and run time.
3. Utilization: Detailed charger utilization information that signals uneven charger usage and identifies faulty equipment.
4. Mispick: Provides operator accountability by identifying the date and time of each mispick.
5. Energy usage: Shows when and how much energy is used in the battery room, helping to guide decisions about potential load shifting or peak shaving activities.

Some battery management systems offer a barcode scanner option, which enables managers to track, organize and report individual battery run times, individual lift truck utilization and dead man hours.

Battery room management systems offer another major benefit for users: the ability to right-size the battery fleet. Right-sizing is the subject of the third in my series of articles on creating a Lean battery room.