Have you ever been stuck with a dead car battery? Did you know that distilled water will bring it back to life?
How Batteries Work
Let’s take a step back, and break down how batteries work. There are three components in a battery which draw out electrical currents, these are the separator, the electrodes and the electrolyte. These three components work together to create an electrical current through a chemical reaction. The other chemical combinations which are commonly used are Lead and Lead oxide. When in use the compounds will form a compound called Lead Sulphate. This chemical reaction is what creates the electrons which stark your car and run the electronics.
So where does the water come in? Well, these newly-created electrons need a medium to flow through within the battery. Water provides this pathway towards the electrodes which in turn carry the current to the car. Through this whole process, the water is also subject to a chemical change, which often means that it evaporates, which in turn reduces the performance of the battery.
Why Distilled Water?
The reason we use distilled water for our car batteries is down to how it evaporates. Regular tap water contains minerals such as iron and calcium which do not evaporate and turn into mineral compounds within the battery. The compounds restrict the flow of the electrons through the water and reduce the efficiency of the battery.
The slightly acidic nature of distilled water, which makes it not recommended for drinking, actually makes it better for car batteries. This acidity in this purified water arises in the distillation process where carbon dioxide from the air mixes with the water vapour creating a weak carbon acidic solution.
Newer batteries are sealed reducing the evaporation of water. This does mean that they do not have to be refilled and that they must be replaced when they are not holding the charge.