WHY DOES BATTERY NEED WATER?
Most batteries work on electrolyte method in which water or distilled water acts the electrolyte in between two different metal plates. The electrolyte in a flooded battery is a pure water. Distilled water for the inverter battery is recommended for batteries as it does not contain any additional minerals that might be in water, such as ordinary tap water. Adding chemicals and minerals can significantly shorten battery life. Distilled water should be the only thing added to deep cycle batteries.
With lead-acid batteries, the purity of the water can have a major impact on the performance of the product. For maximum performance, water consumption should be considered a priority. The common misconception is that any type of water can be used. Natural waters can vary significantly in the number of pollutants they contain. Some factors are the source of water and the time of the year. Throughout the country, there are different sources of water with different amounts of contamination. Contamination in the water source is an important factor in battery performance and battery life.
TYPES OF WATER-
Distilled water is most commonly used for batteries. Other types of water that is used as electrolyte are deionised water and reverse osmosis water. Tap water should not be used as it may contain excessive amounts of contaminants that will affect battery performance. Distilled water is made by distillation, in which water is boiled, steam is captured, and then cooled back into water. This process produces a mineral-free product that has left the contaminants in the original water sample.
Deionized water is the purest type of water, but it is also most heavy on expenditure. The deionization process removes the ionisable particles (organic and inorganic) from the water through ion exchange. Positively and negatively charged ions are removed from the water and are replaced by H+ and OH- ions and these two ions combine to form H2O or purified water.
Reverse osmosis is a method of removing solids from water by forcing it through a membrane. The membrane rejects all particulates while allows the passage of purified water. The choice of the membrane determines the number of contaminants the water will have. This is one of the best alternatives to battery water.
MAXIMUM AMOUNTS ALLOWED -
When talking about the purity of the water, the amount of solid impurities dissolved in the solution must be considered. So, the problem is the maximum allowed amount of contaminants that the water can contain and that are still acceptable for battery use. The parts per million numbers was developed to address this problem. The battery literature suggests a count of parts per million that does not exceed 100.
Mineral content may be minimal in some types of water. The effects of gassing when charging a storage battery, along with evaporation, can leave mineral impurities in the electrolyte solution. So the minerals have a cumulative effect within the battery.
Impurities decide malfunctioning of battery. The impurities may hinder both the positive and negative plates. Impurities may also cause a variety of reactions in the battery, hence different behavioural characteristics. Some impurities influence the metallic components only, and some affect the separators. This scenario will lead to a drop in performance in any case.
An increase in self discharge in one of the two plates is the most common effect. This depletes the battery capacity more quickly. Impurities that enhance self-discharge properties often have an impact on life cycle and charge voltage. The life cycle is reduced, and the charging voltage is reduced. Ultimately, it will degrade the overall performance of the rated battery.
RO water has almost minimum to no contaminants as well as pollutants, so it can work as one of the best electrolyte medium in batteries.
In summary, distilled water is the cheapest type of water for the best overall battery performance. It is also important that the water is filled to the correct level. For standard batteries, the electrolyte level should be 1/8" below the bottom of the breather, approximately 1/2" to 3/4 "above the top of the plates. But RO water is a good alternative, cheaper and easier to distilled water for use in batteries as an electrolyte.