Cordless Phone Batteries

If you had a nickel battery for every time you charged…

It seems like cordless phone batteries take on a life of their own. They can seem stubborn, lazy, and unwilling to be inspired. With nickel-cadmium batteries, there are even names for this phantom ailment: "battery memory syndrome," or the weightier, science-fiction like trauma of "memory effect." Understanding the chemistry within cordless phone batteries will help you make sense of their sometimes-willful ways.

Nickel-cadmium cordless phone batteries

All cordless phones require rechargeable batteries to be used in their handsets. A cordless phone battery is recharged by setting the handset within the cradle on your cordless phone's base station or additional charger.

Though their popularity is beginning to wane, nickel-cadmium batteries are still being used in many cordless phones. Nickel-cadmium cordless phone batteries, known as NiCd or NiCad, contain cadmium, a toxic metal that must be disposed of properly. Part of the cost of a NiCd cordless phone battery is a fee for this disposal.

NiCd cordless phone batteries remain popular because they are cheap and their self-discharge rate is low, meaning they can sit unused for longer periods without losing much power.

However, NiCd cordless phone batteries also have a reputation for losing memory. This problem is said to occur when a NiCd cordless phone battery is recharged before it's been fully discharged. The theory is that if a NiCd cordless phone battery with a 4-hour life is repeatedly used for only 1 hour and then recharged, the battery will begin to think it has only a 1-hour life.

Because of this problem, it's recommended that when using a NiCd cordless phone battery you always allow the battery to completely run down before recharging.

Nickel metal hydride cordless phone batteries

Nickel metal hydride batteries, or NiMH, have begun to replace NiCds as the dominant cordless phone battery. NiMH cordless phone batteries are more environmentally friendly than NiCd batteries because they don't use cadmium. They also suffer less from voltage depression than do NiCd cordless phone batteries. Voltage depression is a drop in peak voltage caused by overcharging, which is a common problem with cordless phone batteries.

A NiMH cordless phone battery will have a shorter life than a NiCd cordless phone battery, but it will also stand up better to the constant, random charging that tends to occur with cordless phone batteries. A NiMH would thus make a good cordless phone replacement battery.

Taking care of your cordless phone batteries

Proper care of your cordless phone batteries will help ensure longer life and power. Here are a few tips to follow:

Keep a cordless phone replacement battery on hand. If you store your cordless phone replacement battery in a cool, dry place at room temperature, it can sit for up to two years.

New  cordless phone batteries need to be recharged or initialized to reach their full capacity. Charge your cordless phone replacement battery overnight before using it.

If your cordless phone battery is already fully charged, do not put it back in the charger to try and gain just a little more power. This will have the unintended effect of damaging your cordless phone battery and shortening its life.

More information on cordless phones