Batteries have a mind of their own. Their stubborn and unpredictable behavior has left many battery users in awkward situations. And yet, the battery is our steady travel companion that allows us to carry out our activities disconnected from home and office. In this paper we observe the battery in personal use and fleet applications.
The personal battery user
It is interesting to observe that batteries cared for by a single user generally last longer than those operating in an open fleet environment where everyone has access to but no one is accountable for them. A personal user is one who operates a mobile phone, a laptop or a video camera for pleasure or business. He or she will likely follow the recommended guidelines in caring for the battery. When the runtime gets low, the battery gets serviced or is replaced. Critical failures are rare because the owner adjusts to the performance of the battery and lowers the expectation as the battery ages.
The fleet battery user
The fleet user, on the other hand, has little personal interest in the battery and has no tolerance for a pack that is less than perfect. He simply grabs a battery from the charger and expects it to last through the shift. The battery is returned to the charger at the end of the day, ready for the next person. Regular battery maintenance is minimal and performance often starts to degrade after one year of service.
How can fleet batteries be made to last longer? I examined the US and the Dutch Army, both of which use fleet batteries. The US Army issues batteries with no maintenance program. If the battery fails, another pack is released, no questions asked. Little or no care is given and the failure rate is high.
The Dutch Army, on the other hand, has moved away from the open fleet system by making the soldiers responsible for their batteries. This change was made in an attempt to reduce operational costs and improve reliability. The batteries are issued to the soldiers and become part of their personal belongings. The results are startling. Since adapting this new regime, the failure rate has dropped considerably and the battery performance has increased. Unexpected down time has almost been eliminated.
It should be noted that the Dutch Army uses exclusively nickel-cadmium batteries. Each pack receives periodic maintenance on a battery analyzer (Cadex) to prolong service life. Batteries that do not meet the 80% target capacity setting are reconditioned; those that fall below target are replaced. The US Army, on the other hand, uses nickel-metal-hydride, a battery that has higher energy density but is less durable. The US army is evaluating lithium-ion batteries for the next generation battery.
What lack of battery maintenance can do
Batteries get checked when they no longer hold charge or the equipment is sent in for repair. In an effort to improve reliability and cut replacement costs, many organizations have adapted some type of battery maintenance.
A user may feel that his or her battery works adequately during routine days, not knowing that the pack holds only half the capacity. A system must be fit to operate in unforeseen circumstances and emergencies where every watt of battery power is needed. Breakdowns during these critical moments are all too common and weak batteries are often to blame. The loss of adequate battery power is as detrimental as any other malfunction in the system.I have recorded a number of stories in which lack of battery maintenance was evident: