The Complete Handbook of Outdoor Power Equipment Batteries

Chapter 1: Understanding Outdoor Power Equipment Batteries

Every piece of battery-powered outdoor equipment, from a handheld leaf blower to a 60-inch zero-turn mower, is only as useful as the battery that feeds it. Unlike a corded tool, which draws unlimited power from the grid, battery tools carry a finite amount of energy. That energy is stored in a chemical form, and releasing it on demand is a process of controlled reactions that must be managed carefully to deliver high current without overheating, to avoid rapid self-discharge when sitting idle, and to survive thousands of charge and discharge cycles without losing capacity.

You can think of a battery as a small, contained chemical reactor. Inside the sealed case, two dissimilar materials (called electrodes) are bathed in an electrolyte, a substance that conducts ions. One electrode, the anode, releases electrons during discharge. The other, the cathode, accepts them. The electrons cannot travel through the electrolyte, so they are forced to travel through an external circuit. When you press the trigger on your chainsaw, you are closing that circuit. The electrons flow through the motor, spinning it, before returning to the battery. Meanwhile, positive ions travel through the electrolyte inside the battery to balance the charge. This entire process is called an oxidation-reduction reaction. When the battery is plugged into a charger, that process is reversed. A charger pushes electrons back into the anode, restoring the chemical potential energy.

For decades, the standard chemistry in outdoor power equipment was the lead-acid battery, the