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.
In the third article in this four-part series, I discussed the impact of right-sizing a battery fleet, which offers significant potential cost savings by properly matching battery inventory to the operational needs of your forklift fleet. Too few batteries, and they will be over-utilized, reducing battery run time and battery life. Too many batteries, and unused assets are being wasted.
The final major impact on battery room operation and maintenance is battery watering. Watering industrial batteries has been called “a simple job done poorly.” There are two seemingly simple steps in the battery watering process:
1. Determine which batteries need watering
2. Water them
But both of these steps are fraught with potential pitfalls. In most warehouses, batteries are watered on a set schedule – typically every week. Not only can this be a complicated procedure, but also a time waster, as many of the batteries that are checked don’t need watering. Many that are checked needed watering far earlier, and costly, permanent damage may already have been done to the battery.
The original method of determining which batteries need watering – a method still used in many warehouses – is checking every battery every week. This is an extremely time-intensive activity, as personnel remove each vent cap and peer inside each cell to determine the electrolyte level.
The fastest way to determine when batteries need watering is with battery watering monitors, which attach to the top of each battery. Monitors allow watering on a labor-saving as-needed basis instead of a hit-or-miss schedule. Most monitors feature an electronic probe to accurately gauge electrolyte levels and a device – typically a small LED – that illuminates or flashes when levels are low. Battery watering monitors not only save money and improve productivity, but enhance warehouse safety by reducing employees’ exposure to acid.
The precise watering of batteries is critical to proper maintenance, long run time and long life. Over-watering can cause boil overs, creating a hazardous condition. But it also decreases the battery’s useful life because during a boil over, sulfates are washed out of the battery, and sulfates are needed to maintain capacity. For every boil over, the battery loses approximately 3% to 5% of its capacity, which equates to 15 to 25 minutes of run time. Over time, boil overs can decrease the life of a battery by six months or more.
Under-watering can happen when batteries aren’t watered on schedule or when they are manually watered and the operator accidentally skips a battery or cell. When a battery or cell is skipped in a typical watering regimen, it might not get the water it needs for another week. When parts of the battery’s positive and negative plates get dry, battery capacity is decreased. And even when water is re-introduced to the dry cell – for example, 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.
The most common factor contributing to over- and under-watering is the hand-watering of batteries. An estimated 70% of industrial batteries in North America are filled by hand, despite the fact that single-point battery watering systems have been available for years.
Single-point watering systems are placed permanently on top of a battery. Valves – or with some models, precision level-sensing injectors – are installed into each cell on a battery. Tubing runs through each valve or injector, forming a single, continuous flow path on top of the battery. The operator clicks on a water-hose, opens a master flow valve and waters a single battery in as little as 15 seconds – a fraction of the time it takes to water a battery by hand.
Single-point watering systems save money in two ways. First, they cut labor costs, often paying for themselves within their first year of operation. Second, they extend the life of each expensive battery on which they are installed due to improved quality of watering. One survey of single-point watering system users revealed that in an average 100-battery fleet, a warehouse or DC can expect to save approximately $26,000 per year with an ROI of about 13 months. Survey participants considered labor savings from the decreased time spent watering batteries, time saved due to less frequent battery changes and savings from less frequent battery purchases as batteries experienced longer lives with proper maintenance.
Single-point watering systems also improve safety and environmental cleanliness. There is no need to peer into cells to inspect levels as with manual filling, and single-point systems automatically fill each cell to the correct level, eliminating the risk of electrolyte overflow during a charge.
The warehouse and DC battery room is the last frontier for the implementation of lean practices. Yet the Lean Battery Room can be immediately implemented with existing technologies and proper maintenance and operating practices. The potential benefits are enormous, representing tens of thousands of dollars in savings from reduced waste even in small- to mid-sized battery rooms.