Battery Safety

Battery Safety

Safe Handling and Use of Lithium Ion Batteries for Power Tools

Close up of hands placing Li-ion battery onto charger.

Li-Ion Batteries

For over two decades lithium-ion (Li-Ion) batteries have become the most used power tool battery source. Li-Ion batteries provide high energy density (more energy in a smaller size), low-toxicity materials, no memory effect, and slow 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 tools, has resulted in a dramatic increase in their use.

Close up of cordless battery drills.

How Li-Ion Batteries Work

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

Play the video for important tips on battery safety, selection, use, and disposal.

Play the video for important tips on battery safety, selection, use, and disposal.

Battery Safety Considerations

Each original equipment manufacturer (OEM) has its own proprietary control circuity for the battery management system, which encompasses the tool, battery, and charger. This is so the three components communicate properly. There are numerous design considerations manufacturers address 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; compliance with standards and 3rd-party certification; etc.

For all these safety and compliance considerations, batteries are not cross-compatible across different brands and manufacturers (unless specified by the power tool manufacturer). When buying aftermarket batteries for power tools, it is important to consult with the power tool owner’s manual and purchase only the batteries recommended by the manufacturer.

More Safety Considerations

  • You must always read your manufacturer’s instruction manual (battery, charger, and tool) for complete information
  • Only use original manufacturer’s system components – tool, battery, and charger. Each manufacturer utilizes their own unique control circuity which allows the system to communicate properly. This system monitors and controls critical functions, such as cell balance, energy levels, flow of energy in/out, and temperatures.
  • Do not impact or damage a battery (e.g., do not use it as a hammer), use it solely for the defined purpose as specified by the manufacturer. Inspect your battery regularly for signs of damage, such as crushing, cuts, punctures, leaking, swelling or deformation. Do not use a battery that has received a sharp blow, been dropped or is damaged.
  • Never modify, disassemble, or tamper with the battery. The performance of damaged or modified batteries can be unpredictable and dangerous. Do not short circuit the battery terminals. A battery pack will short circuit if a metal object makes a connection between the positive and negative contacts on the battery pack. Do not store or transport the battery in a container with loose metal objects, such as coins, keys, or nails, which may contact the terminals.
  • Be mindful of abnormal battery behavior – failure to fully charge or hold a charge, longer-than-usual charging times, noticeable drop in performance, unusual LED activity when placed on a charger (with batteries so equipped), liquid leakage from the battery, or melted plastic anywhere on the pack. These are indications of an internal problem.
  • Use and store your battery within the temperature limits stated by the manufacturer. Do not store in a closed location where sunlight may cause elevated temperatures, such as near a window inside a vehicle.
  • As a general practice, it is best to unplug battery chargers and remove battery packs when not in use. Do not store batteries on their chargers.
  • Never burn / incinerate a battery or expose to a heat source – it may explode.
  • Do not immerse the battery or allow any fluids to flow inside. Conductive liquid ingress, such as water, can cause damage resulting in fire or explosion. Store your battery in a cool, dry place, away from combustible and flammable items. Corrosive gas atmospheres must be avoided.
  • If you suspect your battery may have a problem, do not use, ship, or discard as normal trash. Always dispose of your battery pack according to federal, state, and local regulations. Contact a recycling agency in your area for recycling locations. Even discharged battery packs contain some energy. Before disposing, use electrical tape to cover the terminals to prevent the battery pack from short circuit.
  • There are also carrier requirements that need to be considered when shipping Lithium-Ion batteries (see resources below for examples).
  • Do not attempt to revive a battery that will not take a charge. Do not jumpstart, use other batteries, or use other power sources. Doing so may cause battery damage that can result in burns, fire, or explosion.

Additional Resources

Disclaimer: This document is provided by Power Tool Institute (“PTI”) for informational purposes only. Any inaccuracy or omission is not the responsibility of PTI. PTI does not make any representations or warranties with respect to this document or its contents. PTI hereby disclaims all warranties of any nature, express, implied or otherwise, or arising from trade or custom, including, without limitation, any implied warranties of merchantability, noninfringement, quality, title, fitness for a particular purpose, completeness or accuracy. To the fullest extent permitted by applicable laws, PTI shall not be liable for any losses, expenses or damages of any nature, including, without limitation, special, incidental, punitive, direct, indirect or consequential damages or lost income or profits, resulting from or arising out of a company’s or individual’s use of this document, whether arising in tort, contract, statute, or otherwise, even if advised of the possibility of such damages.

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