Power Tool Batteries and Battery Chargers

To keep cordless tools working properly, it's important to select the right batteries and battery chargers. There are several different types of power tool battery technologies to choose from. Tool users need to consider other factors as well, ranging from charge time to voltage.

What are the types of rechargeable batteries for power tools?
  • Lithium-Ion Battery (Li-Ion): Lithium-ion batteries are lightweight, resistant to temperature-change damage, and available in a wide variety of shapes. They have a long charge/recharge life cycle, and they're rarely damaged by recharging or inadequate storage.
  • Nickel Metal Hydride Battery (NiMH): Nickel metal hydride batteries have high energy densities, which ensures extended charge times. Appropriate storage can extend their cycle life, and they are environmentally safe.
  • Nickel Cadmium Battery (NiCad): These batteries are the oldest battery type, but they're still in use thanks to their long cycle life and impressive durability.
How should power tool battery chargers be selected?

To ensure a long battery life, it's important to choose a high-quality battery charger. Most chargers are categorized by their charging speed. Slow chargers require a charge time of 14 to 16 hours, quick chargers require three to six hours, and fast chargers require about one hour.

Lithium battery chargers, however, work at one speed. These chargers deliver a full charge after approximately three hours.

What are the characteristics of rechargeable batteries for power tools?
  • Self Discharge: This measures the rate at which batteries lose their charge when not in use.
  • Cycle Life: This measures how many times the battery can be recharged over the course of its life.
  • Voltage: Voltage reflects how much power a given battery can deliver to a power tool. Higher voltages equal more power. Traditionally, voltage ranges from 7 volts to 36 volts.
  • Deep Discharge: This is when a battery, through standard power-tool operation, is completely drained of energy. For some batteries, this type of discharge is essential to their longevity.
  • Capacity: This is a measure of how long a battery can perform before it requires a recharge. Capacity is reflected in terms of a battery's amperage hours (Ah). A larger Ah means users can use their cordless tools for more hours between charges.
What shapes do power tool batteries traditionally come in?

When buying replacement batteries or battery packs, it's important to choose the right shape for each tool. Batteries are made in the following shapes:

  • Pod
  • Stick
  • Slide
What are some manufacturers of power tool batteries and chargers?

Some brands you’ll encounter include:

  • Dewalt
  • Makita
  • Milwaukee
  • Craftsman
  • Ryobi
  • Bosch