Understanding the Voltage Requirements for Riding and Push Mower Batteries
Battery-powered starting systems on lawn mowers depend on a rechargeable battery to crank the engine. The electrical architecture of the mower determines whether a 6-volt or 12-volt battery is needed to supply the necessary power.
By Rowan Davis
Not all lawn mowers use the same voltage battery.
When a lawn mower is equipped with an electric starter, it relies on a battery as a critical part of its operation. Without this battery, the mower will not start. The specific electrical system of the mower dictates whether it needs a battery that delivers 6 volts or 12 volts of electrical energy.
The Role of the Battery in a Lawn Mower
The purpose of the battery in a lawn mower is to supply the electrical current needed to spin the starter and begin the ignition sequence. These batteries are small lead-acid units and can typically be found at hardware stores or auto parts retailers.
How Chemical Reactions Generate Voltage
Inside a lawn mower battery, there are multiple individual cells. Every cell is made up of a positive electrode composed of lead oxide and a negative electrode made of lead. Both electrodes sit in an acidic electrolyte solution. The chemical interaction between these two electrodes creates a voltage difference of 2.1 volts per cell.
6-Volt Lawn Mower Batteries
A 6-volt lawn mower battery is constructed with three cells connected in series. This configuration delivers 6.3 volts of direct current (DC) electrical energy. If the label on a 6-volt battery is unclear, you can determine its nominal voltage by counting the cell vent caps on top of the battery case. Because the battery has three cells, it will have three vent caps.
12-Volt Lawn Mower Batteries
A 12-volt battery has six cell vent caps. The vent caps on this battery are yellow and are placed at the top of the battery.
A 12-volt lawn mower battery is made up of six cells wired in series. These batteries supply 12.6 volts of DC electrical energy. On the top of the battery case, you will find six vent caps. In electric-start lawn mowers, 12-volt batteries are used more often than 6-volt batteries.
