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Water Quality and Its Impact on Lead-Acid Batteries

Maintaining the water in your lead-acid battery is critical to top performance and durability. Even in today’s modern age, lead-acid batteries function the same way they did over 150 years ago. They still require the same upkeep to maintain the chemical reaction that allows a lead-acid battery to produce electricity.


Why Water Quality and Proper Levels are So Important 

Lead-acid batteries are made up of positive and negative plates submerged in an electrolyte pool consisting of sulfuric acid and water. This pool is essential for allowing ions to flow between the plates, creating electricity.

Throughout the recharging process, water is broken down into hydrogen and oxygen gas as electricity is passed between the lead plates. As the water surrounding the plates is turned into gas, the water levels begin to drop, preventing the battery from operating at peak performance. That’s why consistent watering is essential to sustaining the delicate chemical balance lead-acid batteries need to operate. 

Using the Correct Type of Water

Not just any type of water will do when topping off your battery’s fill well. Minerals including Aluminum, Arsenic, Barium, Cadmium, Chromium, Copper, Iron, Lead, Mercury, Selenium, Silver, and Uranium are all found in your average tap water and can damage your battery’s operational capabilities. 

Of these, iron is the most damaging to your lead-acid battery but the presence of other minerals only compounds its effect. The presence of these contaminants as your battery is charged at high rates can significantly reduce its lifespan. As the lead-acid battery works to generate electricity, the contaminants in the acid solution inhibit the electro-chemical reaction. The end result is an increase in cell resistance, causing elevated temperatures and early plate degradation.

Distilled water is the safest choice and our recommendation when watering your lead-acid batteries. Another option would be to use de-ionized water, however it should be tested for contaminants prior to use.