(Courtesy: Steve at flickr.com)
In the story entitled Tackling Waste In the Battery Room I discussed how warehouse managers can limit or eliminate waste in the battery room by identifying the waste, creating a plan to alleviate it, measure progress and evaluate performance and make adjustments in the plan.
One specific action that can be taken is to create a more efficient way to select batteries from the battery room. This can be done with the use of a battery management system.
To achieve better results in the run time and life of batteries warehouses should adopt a battery rotation method.
Proper battery rotation is actually up to the forklift operators who make their own battery selection to take the correct battery from a collection of batteries in the battery room.
It is not uncommon for forklift operators to take the closest battery to them to perform the quickest change or the newest battery thinking that they are getting one with the longest run time.
Actually, the proper battery to select is the one that has had the longest cool down time since charging. The fact that these batteries may be in the back of the battery room discourages their selection.
Selecting the wrong battery can be costly. Tests have been performed that show that when battery selection is left up to a forklift operator, about 30 percent of the batteries will be underutilized and 20 percent of them will be overused. The result of all this is that battery usage will be uneven and this can lead to premature battery failure and lost productivity.
The key to ensuring proper battery selection is to select the battery that has had the longest cool down time since charging. Making the selection of the right battery should be easy to do and the person doing the selection should be made accountable.
When proper battery rotation is performed, the results are dramatic. In a study of good battery rotation practices in which data was collected for three months before and three months after proper battery rotation procedures were introduced it was discovered that the average battery run time increased from six hours 30 minutes to six hours 57 minutes. Some who advocate proper battery rotation say that there is no reason forklift fleets can’t achieve eight hours of run time from their batteries.
An advantage of performing proper battery rotation can also help determine exactly how many batteries a forklift fleet needs, thus avoiding the acquisition of too many batteries.
A good method of battery room management ensures proper battery rotation and thus reduces waste in the battery room.
The best battery management system measures the charger to determine which battery has had the longest cooling time since charging. Once charged, each battery is placed in a queue. A simple read and react display should be used that tells the operator which battery to choose. An audible alarm that alerts the operator when he is selecting the wrong battery could prove beneficial.
Some systems directly measure the charger to obtain accurate data on the state of charge of each battery and automatically report that to the Cloud. The Cloud can then generate easy-to-understand reports that can be conveniently available using any web browser. These reports offer feedback and can caution managers when certain alert conditions are triggered. These conditions can include:
· Availability of batteries. This assists managers to determine if they have too many or too few batteries.
· Cool down. This shows how much cool down time the batteries have obtained. Keep in mind that hot batteries shorten life and run time.
· Utilization. Detailed data on charger utilization can signal an uneven charger use and identify faulty equipment.
· Mispick. Data can identify operator accountability by detailing the date and time of a mispick.
· Energy usage. This indicates when and how much energy is used in the battery room that can help in adjusting load shifting or peak shaving activities.
Some battery management systems use a barcode scanner so that managers can track, organize and report individual battery run times, individual forklift utilization and dead man hours.
(Next: Right-Sizing the battery room)