Can you put water in a car battery?

The car batteries need an adequate level of water to stay fully functional. Many people assume that installing a battery means that they are free from any other added responsibility but it is not true. You need to maintain an adequate water level in the car battery to ensure that it is fully functional.

Almost half of the battery failures (before useful life) happen due to low water levels. As users forget to check and fill in the water in their batteries resulting in high acidic concentrations within the battery that can cause damage to the battery and affect its performance. 

To understand the required level of water, the procedure to add water, and, the symptoms of a low water battery keep reading the article.

How much water does a car battery hold?

The water-containing capacity of a car battery cannot be described in terms of liters of water. A battery can hold water up to the top lid or cover of the battery. But this is not recommended. If you fill the water up to the very top of the battery then it will overflow or spill once the battery starts to operate which can cause serious damage to the battery user and car. This is why water should be added to a prescribed level as determined by the battery manufacturers. 

The basic function of the water in car batteries is to offer dilution to the electrolyte (which is Sulphur in most cases). So the water quantity should be such that it surrounds the electrolyte plates of the battery and offer the required dilution to maintain the concentration of electrolyte within the battery. This is why the required water level cannot be described in terms of quantity in liters rather it is appropriate to specify it in form of the water level that soaks the electrolyte plates. 

3.2V 20A Low Temp LiFePO4 Battery Cell -40℃ 3C discharge capacity≥70% Charging temperature：-20~45℃ Discharging temperature: -40~+55℃ pass acupuncture test -40℃ maximum discharge rate：3C

READ MORE

The adequate water level below the bottom of each tube extending from the top or opening of the battery should be ? inch and a maximum of 1/8 inch. 

Make sure to always use distilled water in the battery. The minerals in tap water contain minerals that can reduce the output of the battery and elevate the self-discharge rate of the battery.

How to add water to a sealed car battery?

Many users assume that a sealed car battery can be opened as they take the word “sealed” in its literal meaning. The great news is that you can open up a sealed car battery and refill the exhausted water level. It is always better to get professional help but you can do it on your own as well. You should always wear protective gear like safety glasses and gloves and take good care while filling water in the car battery. Remember caution is required to fill in the batteries because if overfilled, the acidic water can overflow causing serious injuries. The steps needed to add water to a sealed car battery are as follows:

Make sure that the battery is not operational. It implies that the car engine is off.

Pry open the top lid or cover of the battery using a flat screwdriver.

Take off the covers of cell vents. You can do this easily with a needle nose plier.

Low Temperature High Energy Density Rugged Laptop Polymer Battery Battery specification: 11.1V 7800mAh -40℃ 0.2C discharge capacity ≥80% Dustproof, resistance to dropping, anti - corrosion, anti - electromagnetic interference

READ MORE

Once the cell vents are exposed, you can add water to the battery. It is advisable to use a funnel or container with an easy-pour feature to add the water without any fear of spilling. Make sure to use only de-ionized or distilled water. Make sure to fill in the water to the required level to prevent it from spilling. 

Put the rubber caps back on the cell vents. 

Cover the top of the battery and put a towel on it. Connect the battery to a charger and see if it is charging without any spilling acidic water to ensure that you have added water as per the required level. Also, ensure that the battery is charging.

Once you have checked the battery, you might want to seal it back. You can stick the cover back by using a mild adhesive. Make sure that the battery is not fully sealed as you might appreciate leaving an escape outlet for gasses. 

Low Water in Car Battery Symptoms

Many noticeable symptoms point towards low water levels in your car. You need to be vigilant to notice any slight change in the car’s performance or battery’s output and take necessary action on an urgent basis. It is always better to develop a habit of checking the water level in the car’s battery regularly. A few of the most prominent symptoms of low water levels are as follows:

Reduction in overall capacity: The battery should have a balanced proportion of electrolytes and water. When the water level falls short then it leads to a concentration of sulphuric acid causing sulphation on battery plates. This leads to quicker battery discharge as there is less water to aid in the dilution of the acid. You will experience quick battery drainage and notice that the battery is unable to hold the charge for a longer period (like it used to).

Slow Cranking: With a low water level, the overall concentration of the battery becomes inadequate. It is so because the sulfate will be attracted or tied up towards the negative electrode reducing the concentration level inside the battery. This lower concentration affects the battery output and causes problems for you. If you are unable to detect the low output in the initial time then it will lead to a point where the car’s performance will also be affected. Your car might need a longer time to start or the performance of electrical equipment (like car AC) will be compromised. 

Chances of Corrosion: Adequate water level helps to maintain the acidic concentration level inside the battery. When the water level falls then it exposes the plates of the battery to the environment. When the electrodes are exposed to a higher oxygen supply it can cause corrosion on the terminals of the battery.