How Rechargeable Batteries Work

Like primary batteries, rechargeable batteries have four basic components—a positive electrode (cathode), a negative electrode (anode), a separator and electrolytes. But that’s where the similarities end. The chemicals inside a rechargeable battery are reversible, allowing them to be recharged again and again—the Energizer Rechargeable Nickel Metal Hydride AA battery, for example, can be recharged up to 1000 times. Rechargeable batteries offer good performance and cost less per usage than their alkaline counterparts.

Rechargeable batteries are ideal for high drain devices that use a lot of power. But they should never be used in smoke detectors and are not recommended in other low drain devices. Here’s why: Primary batteries are—turned on— when they’re inside a device and the device is operating. But rechargeable batteries lose some of their power everyday, whether they are in a device or not—so it’s important to re-charge them often to maintain maximum capacity.

What are the differences between battery types?

Primary batteries have a single use and cannot be recharged. Primary cell batteries include alkaline, carbon-zinc, lithium, silver-zinc and zinc air.

Secondary batteries contain reversible chemical materials allowing them to be recharged and used again. Examples of rechargeable systems include Nickel Metal Hydride (NiMH), Nickel Cadmium (NiCd), Lithium Ion (LiIon) and Sealed Lead Acid (SLA) batteries.

Care and handling of your batteries
Battery Do's and Don'ts

Do read the instructions on your device before installing batteries. Make sure to insert the batteries properly, following the symbols showing you the correct way to position the positive (+) and negative (-) ends of the batteries.

Do keep battery contact surfaces clean by gently rubbing with a clean pencil eraser or cloth.

Do replace batteries with the size and type specified by the device's manufacturer. Remove all used batteries from the device at the same time, then replace them with new batteries of the same size and type.

Do store batteries in a cool, dry place at normal room temperature. Remove batteries from devices that will be stored for extended periods.

Don't dispose of batteries in a fire—they may rupture or leak.

Don't carry loose batteries in a pocket or purse with metal objects like coins, paper clips, etc. This will short-circuit the battery, generating high heat.

Don't recharge a battery unless it is specifically marked "rechargeable." Attempting to recharge a normal battery could result in rupture or leakage. Don't use rechargeable alkaline batteries in nickel metal hydride battery chargers.

Don't put batteries or battery-powered devices in hot places—elevated temperatures increase the self-discharge of batteries.

Don't mix old and new batteries, or mix different types or makes of batteries. This can cause rupture or leakage, resulting in personal injury or property damage.

Don't give batteries to young children.