A battery is a device made up of electrochemical cells. The term battery refers to a device composed of multiple cells; however, the usage batteries now have a single cell. It has external connections that are used to power electronic devices like flashlights, mobile phones, electric cars, etc. the battery provides electricity due to electrons' flow. The circuit is completed when an electronic device is connected across both terminals of the battery. Broadly speaking, there are two types of batteries. 

1.Primary Battery is non-rechargeable batteries and designed to be used until all the energy is exhausted. Example: use and throw batteries (example: button cells. AA & AAA batteries).


2.Secondary Batteries- They are the batteries that can be recharged because the chemical reaction in them can be reversed by applying an external electric current. Standard inverter batteries are the best example of this type.


Adding water to batteries is an essential part of battery management because it helps in prolonging the life of the battery and prevents costly battery replacement. If you don't add water to your electric batteries regularly, it might lead to plate drying and ineffective conduction of electrons through the battery.


Tap Water in Deep Cycle Batteries


A deep-cycle battery is a battery designed so that it is regularly deeply discharged using most of its capacity. Lead-acid batteries are traditionally known as deep cycle batteries. They are constructed so that they deliver only a tiny part of their capacity in a short, high current burst for cranking up the engine. There is an inverse correlation between the number of charge/ discharge cycles it can perform and the depth of discharge. Newer technology in this type of battery includes lithium-ion batteries, which are nowadays used in mobile phones.


To water your lead acid-battery, you should not use tap water because adding tap water will eventually reduce the battery's overall performance and efficiency. It won't have a random effect on the battery, but it is not recommended in the long run.  Lead-acid batteries have lead plates dipped in an electrolyte solution and transfer ions from the electrolyte solution to the metal plate and vice-versa. This flow of ions is responsible for producing current by the battery, and in this process, the concentration of ions changes. To restore the ion concentration back to normal, you are required to add water to your battery.

Putting Tap Water in Car Batteries


A car battery is also known as an automotive battery, is used to start a motor vehicle. The primary purpose of this battery is to provide an electric current to the electric-powered starting motor, which helps create the combustion engine by commencing the chemical-powered reaction that happens in a motor vehicle via the fuel present in the fuel tank. Once the engine is running, power for the car’s electrical system is still supplied by the automotive battery with the help of an alternator that charges and discharges based on power consumption.


Starting a vehicle/ motor usually uses less than 3 percent of the battery capacity. Thus,  car batteries are designed in such a way that they deliver the maximum amount of current possible within a short span. Due to this, car batteries are also called "SLI batteries." SLI means starting, lighting, and ignition. They are not designed for deep discharging, and complete removing may decrease battery life. Apart from starting the engine or stabilizing the voltage, an SLI battery supplies electricity to the vehicle when the vehicle’s demand can’t be met by the charging system. The charging system operates only when the engine is running. 


There is a generation of heat due to the battery's chemical reaction, which results in water loss through evaporation. The battery company recommends refilling the battery with distilled water, but consumers prefer normal tap water as it is free and comes in handy when available. Tap water usually has I purities and salts compared to the distilled water. The chemical impurities interfere with the usual reaction in the cell such that the efficiency of the battery is lost, which increases heat production. The excess heat damages the battery and decreases its life. Now, there are new car batteries that are maintenance-free, meaning they don't need a refill of water.


Can you put tap water in your battery?


Using tap water for refilling your batteries is a big NO! as tap water contains many elements. They may hinder the chemical reaction that may lead to heat production and leaks in your battery which is very dangerous as it can lead to an explosion of the motor. Tap water also contains metals that, over a period of time, deposit over the metal surface and decrease its surface area, resulting in the ineffective flow of electrons and decreasing battery life; according to the company makers, the water that should use pure, distilled, deionized water for refilling. It is practically inert to the battery and causes no damage.

All in all, the battery is an essential part of an electric device or a vehicle. So always check your batteries from time to time. Always follow the maker's instructions for refilling your batteries. It may have acid and explosive gases. Please follow the do's & don'ts written in the user manual for a better experience and long-lasting battery experience. Please wear protective face and hand gears while handling the battery.