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Buying Guide

Types of Batteries

How Batteries Work
A diagram shows how a battery works.

A battery produces electrical energy upon demand through the battery’s terminals or electrodes. The positive terminal is at the top of most batteries used for consumer goods like flashlights and electronics. The outer case and bottom of the battery make up its negative terminal. The positive and negative terminals are identified on all types of battery sizes. The terminals and the battery’s encased chemicals together comprise the power cell. 

The power cell creates energy when the battery’s positive and negative terminals connect to a circuit – the metal part in a flashlight case, for example – and the device is switched on. The chemicals inside the cell, such as alkaline and lithium, start a reaction producing ions and electrons that power whatever the battery is connected to. 

Alkaline Batteries
A package of D-cell alkaline batteries.

Alkaline batteries are found in most household and office devices like clocks, calculators, games and toys, and smoke detectors. These types of batteries have a shelf life of five years or longer.  

  • Alkaline batteries can be used for high- and low-drain devices but can drain quickly in high-drain devices like digital cameras.  
  • Rechargeable alkaline batteries are designed to be fully charged after repeated use. These are best used with low-drain devices or devices that are used periodically. It can be hazardous to recharge disposable alkaline batteries, so look closely at its label.  
Lithium Batteries
A worker uses a drill powered by a lithium-ion battery.

Lithium batteries are widely used in consumer devices that require heavy electrical current usage, from thermometers and remote car fobs to critical medical devices like pacemakers. These batteries cost more but are designed to meet the demand. 


Lithium-ion batteries (Li-ion) can be found in most portable electronic devices like smartphones, portable power tools and motorized toys. Li-ion batteries are sold in disposable and rechargeable versions. They contain fewer toxic metals than other batteries. The rechargeable batteries have a longevity of 300 to 500 charge cycles, or about two to three years.  

Zinc-Carbon Batteries
A person inserts a pair of general purpose batteries into a device.

Zinc-carbon batteries are general-purpose batteries that are found in devices throughout your house, like the remote control that runs the thermostat. 

Most zinc-carbon batteries have a short shelf life and are best suited for low-drain devices. Super heavy-duty zinc-carbon batteries can last up to five years, but these types of batteries are prone to corrosion once they’ve lost their charge. Zinc-carbon batteries are not recyclable.  

Nickel Cadmium (NiCd) Batteries
A closeup of a nickel cadmium battery.

Nickel-cadmium (NiCd) batteries are rechargeable packs used primarily with portable electronics, power tools, photography equipment and hobby remote control vehicles. NiCd batteries can last for an estimated 1,000 cycles – the time it takes to fully recharge and undergo usage – and work best when completely drained prior to recharging. NiCd batteries must be recycled. 

Nickel-Metal Hydride (NiMH) Batteries
A person inserts a battery into a laptop computer.

Nickel-metal hydride (NiMH) batteries, like NiCad batteries, are rechargeable and used in many electronic devices like smartphones, laptop computers and portable power tools.

NiMH batteries have increased in popularity with consumers because of their performance with heavy-drain devices. They can also operate in devices designed for disposable batteries of the same voltage. NiMH batteries have a shelf life of three to five years. 

Coin and Button Cell Batteries
A coin cell battery inserted in a portable electronic device..

Coin and button cell batteries are disposable alkaline, lithium and silver oxide primary cells that have a long service life. They are found in small portable devices like watches and pocket calculators. There are rechargeable variants of NiCd coin and button cells that are typically used as backup power sources. 

Some coin and button cell battery examples include:

  • CR 1220: These types of battery sizes are used primarily in LED flashlights and digital camera equipment.
  • CR 1616, CR 1620, CR 1632: Primarily used for remote car starters
  • CR 2032: The commonly available lithium and silver oxide cell, it is used for remote car starters and medical equipment.   
Zinc Air Cells
A person replaces a button cell battery used in a hearing aid.

These high-capacity button cell batteries are used primarily in hearing aids. They are air activated, meaning they are ready to use when a factory-sealed tape is removed and oxygen interacts with the zinc in the battery. These batteries remain in an active state until the power is drained, usually about three years. 

Sealed Lead Acid Batteries
A sealed lead automotive battery.

Sealed lead-acid batteries can be mounted in any position and do not require regular maintenance. These types of batteries are often referred to as valve regulated lead-acid (VRLA) batteries. A relief valve activates when the battery begins to generate hydrogen gas. 

Sealed lead-acid batteries are found in motorcycles and all-terrain vehicles, wheelchairs, scooters and boats. They are designed to last up to 12 years. 

Common Battery Sizes
Description Feature/Benefits
AA Batteries 1.5 volts; 1.2 volts NiCd, NiMH Household electronic devices.
AAA Batteries 1.5 volts; 1.2 volts NiCd, NiMH Portable electronic devices and controls.
D Batteries 1.5 volts Flashlights and portable radios.
9v Batteries 9 volts, alkaline and zinc-carbon; 9 volts, lithium (3 cells); NiCD and NiMH, 7.2 volts (6 cells), 8.4 volts (7 cells), 9.6 volts (8 cells) Household devices and sensors like smoke detectors.
C Batteries 1.5 volts Musical instruments, toys and consumer products.
Uncommon Battery Types
6v Batteries
Specialty Batteries
Description 6-volt battery 3.6 volt battery
Feature/Benefits Distinctive by its bulky rectangular shape and spring terminals, this alkaline or zinc-carbon battery comprises multiple power cells inside a housing. These types of battery sizes are found in large flashlights and lanterns. These Li-Ion rechargeable power cells are used mainly in cordless phones, flashlights, power tools, and electronic smoking devices.
Rechargeable Batteries
A lithium battery pack undergoes recharging.

Most batteries are lumped into two categories: disposable and rechargeable. These  categories contain many different types of batteries based on what a particular type of battery is made of and how it stores energy. Batteries such as alkaline, lithium, NiCad and NiMH batteries are designed to be recharged: 

  • The batteries can be charged hundreds of times before needing to be replaced. 
  • They require a higher upfront investment but more economical in the long run. 
  • They are best suited for frequently used, heavy-drain devices. 
  • They may require an adapter or converter for overseas use.


Look for “smart” chargers that charge batteries quickly and then slow the charge to a trickle when batteries are full to avoid overcharging. 

Battery Storage and Disposal Tips
A person places batteries in a bucket for disposal.
  • Store batteries at room temperature. Excessive heat or cold makes a battery wear out faster. 
  • Do not store with coins, paper clips or other metal objects because batteries may short-circuit and heat up. 
  • Remove batteries from devices you don't use all the time to extend their operating life. 
  • Replace all batteries at the same time.  
  • Don't mix old and new batteries. This may cause them to leak or rupture. 
  • Avoid mixing and matching batteries from different manufacturers in the same device. 
  • Alkaline batteries such as D, C, AA, AAA and 9-volt can be disposed of in your regular trash.  
  • Make sure to prevent any fire risk by taping 9-volt terminals before tossing.   
  • NiCad batteries containing lead must be properly recycled to prevent environmental hazards. 
  • Instead of tossing, consider recycling old batteries by taking them to a local battery recycling drop-off. 


Not sure if the battery is recyclable? Look on the side of the battery and see if it says “Battery Must be Recycled” or if it has a recycling symbol. 

It helps to know the right battery that powers your household device. Take the guesswork out by becoming familiar with the batteries you use. Download The Home Depot Mobile App to find the single-use or rechargeable battery you need.