Ensuring Safety and Performance: Choosing the Right Batteries for Power Tools

7/26/2023

The chemistry used in power tool batteries for many years was commonly nickel metal hydride and nickel cadmium. During the past decade, power tools have almost universally converted to lithium-ion (Li-Ion). 

The change came as a result of numerous issues, such as higher energy density, lower-toxicity materials, no memory effect and a slower rate of self-discharge. The benefits of Li-Ion technology have allowed higher-demand tools and applications to be battery powered and provide significantly more work per charge. This extended capability, combined with the portability of battery-powered tools, has resulted in a dramatic increase in their use. 

A battery is designed to direct its energy along defined pathways in a controlled manner. If the energy finds a different, possibly even uncontrolled path – in some cases weeks after an internal fault occurs – it can result in contact with caustic chemicals, burns from escaping chemicals, fire or explosion. The higher the energy density of a Li-Ion battery, the greater the potential to cause damage.  

Each original equipment manufacturer has its own proprietary control circuitry for the total system, which encompasses the tool, battery and charger, which allows the three components to communicate properly. Manufacturers address numerous design considerations in the construction of their batteries: type and quality of cells; durability of electrical connections; electronic controls in the battery, charger and tool; protective housing; and compliance with standards and third-party certifications. 

For all these safety and compliance considerations, batteries are not cross-compatible unless specified by the power tool manufacturer. When buying aftermarket batteries for power tools, it is important to consult the power tool instruction manual and buy only the batteries recommended by the manufacturer. The Power Tool Institute has developed a special program, Take Care of Your Battery, that aims to encourage safe battery use. 

Battery storage and disposal 

Technicians must maintain battery packs and store them safely, away from paper clips, coins, keys, nails, screws and other small metal objects. These items can make a connection from one terminal to the other, shorting the battery terminals together and causing burns or fire. 

Store the battery pack away from extreme temperature conditions. Broken or abused battery packs can leak chemicals that can cause irritation or burns. If a technician comes into contact with these chemicals, flush the area with water immediately. If it contacts the eyes, flush them with water and seek medical help. 

Recycle or dispose of battery packs properly to protect the environment and prevent dangerous conditions that can occur if a Li-Ion battery is damaged or punctured after disposal. Battery pack chemistries also can be hazardous to the environment under certain conditions. 

Refer to the instructions included with the battery pack for the proper disposal or recycling of battery packs. Make sure to follow state, local and federal regulations, since Li-Ion batteries cannot be disposed of with regular curbside recycling or trash. Place electrical tape over the battery pack’s terminals before disposing or recycling. 

For disposal information, call 1-800-BATTERY. Many major retailers in the United States and Canada have battery recycling collection boxes. To locate these sites, visit www.call2recycle.org, or call (877) 723-1297. 

Susan Orenga is the executive manager of the Power Tool Institute, a trade organization whose members represent market-leading brands of portable and stationary power tools.