While working with General Electric, I had the opportunity to examine the behavior of a large number of NiCd batteries for portable radios. There was a certain organization that repeatedly experienced premature battery failure. We discovered that their radios were under-utilized and yet the batteries received a full recharge after each short field use. After learning that the organization had to replace all batteries after a little more than one year of service, we advised them to exercise the new batteries once a month by discharging them to one-volt-per cell with a subsequent recharge.
The first such exercise took place after a delay of four months which was less than ideal with the new batteries. At that time, more than half of the batteries tested exhibited a capacity loss of 25% or more. With exercise and recondition cycles, all batteries were fully restored. The chances of a full recovery would have been jeopardized had maintenance been omitted for much longer.
On another occasion I noticed that portable radios used by construction workers experienced fewer battery problems than, for example, those with security guards. The construction workers often did not bother turning the radios off when they put down their hammers. As a result, the batteries got their needed exercise and kept on performing until they fell apart of old age. In many cases the batteries were held together with electrician’s tape to the very end.
In comparison, the security guards pampered their batteries to death by giving them light duty and plenty of recharge. These batteries still looked new when they had to be discarded after only 12 months of service. (Because of their advanced state of memory, recondition was no longer effective to restore these batteries).
Observing different battery sizes, I studied the performance of a portable radio that was available with two batteries of different capacities. It was soon apparent that the small battery lived to a ripe old age, whereas the larger one needed replacing more often. It is assumed that the small battery had to work harder than the large one and hence received more exercise during its daily routine.
Battery manufacturers are aware of the weak link — the battery. To address the customer’s request for a more reliable energy source, batteries with higher capacities are recommended. Not only are oversized batteries bulky, heavy and expensive, they hold more residual charge prior to recharge than smaller units, resulting in the formation of memory, if not regularly maintained.
In certain cases, switching to the ultra-high capacity batteries solves the issue of increased capacity and small size. It should be noted, however, that these advanced batteries are more fragile than the standard version. Ultra-high capacity batteries tend to get warmer on charge and discharge, have lower load characteristics and offer reduced service life.
The problem of recurring battery failure has always been a thorny issue for the battery user. Complaints are frequently handled poorly as far as the interest of the customer is concerned. The manufacturer’s representative often brushes off a customer’s complaint with a sense of surprise, saying, "Well, we have not experienced this problem before"; or regarding low battery capacity, "Memory no longer exists". A certain degree of denial by the representative is understandable when considering their position: "As long as new batteries sell, there is no problem".
Battery Analyzers for Critical Missions
Strenghtening The Weakest Link
Recycling Of Batteries