Why a Rechargeable Battery Does Not Last Forever

Batteries use an electrical current to power devices outside of themselves. Power is discharged by the battery via a negative-to-positive electron flow. A rechargeable battery reverses this process, and this is how power is restored to a battery. However, over time the rechargeable battery takes on less and less power, and eventually fails to charge at all. To understand why a battery can not always be recharged, read on to learn how a battery releases and recharges energy.

How Batteries Run Down

Batteries use a series of chemical reactions to discharge electricity. As the rate of these chemical reactions slows, so the battery becomes less powerful. The more frequently a battery is used, the sooner these reactions begin to slow. In addition, as well as releasing energy by chemical reaction, other chemical types are also created within the battery, which uses energy. Eventually, there are no more chemical reactions which release energy which are not equalled by the reactions making chemicals using this energy-and the battery cannot provide electricity to the outside device.

How Batteries Are Recharged

Batteries are recharged by adding electricity from an outside source. This adds energy back into mix, meaning that chemical reactions can again take place. However, there are a number of factors which inhibit the successful recharging of a battery. Some batteries may be affected by too-high voltage being used; the more quickly a device recharges batteries, the more likely it is that the battery will become over-charged. This affects the battery cells, making them less likely to hold a good charge in future.

Other Problems with Battery Recharging

By far the most common problem with the rechargeable battery is the so-called “Memory effect.” This happens with nickel-cadmium batteries where the battery is recharged before it has discharged 50 percent of power. This causes cadmium crystals to develop inside the battery cell; these crystals are not reactive to electricity, and inhibit the retention and release of energy. This inhibits the battery from fully discharging in the future—it essentially ‘forgets’ that it can discharge more power.

Rechargeable battery technology also has problems with the effectiveness of the charge-batteries are likely to be less and less effective with each subsequent discharge of electricity, until eventually the battery is unable to take on enough new energy to provide power.

Problems with Chargers

The effectiveness of the recharging is also affected by the charger itself; depending upon the different price tags, some chargers have only weak recharge ability, and this affects the ability of the battery to retain energy.

A common problem in the early years of the rechargeable battery was that original chargers were designed to charge a specific set of cells, and would not charge others; however charger technologies have improved this aspect; universal chargers can now locate the correct chemical type, and charge accordingly. Smart chargers have been developed with a range of technologies to adapt to different batteries components. Nevertheless, due to the inherent problem with chemical reaction within the rechargeable battery, all battery cells age in the same way, and the longer that they are utilized, the less ability to provide energy they have; and that is why no rechargeable battery can really last forever.