Symptoms And Solutions Of Low Water In Car Battery

The last thing that you expect to happen with your car battery is its low water level. With time the water level drops. Do you know the symptoms of low water level? How do you know the battery has low water? How can you increase the water level?

Well, you will certainly notice a massive performance drop from the battery. Its capacity is reduced. Corrosion builds upon the exposed top of the plates due to the absence of water. Also, you’ll notice slow cranking frequently.

Your car battery runs out of water for mainly overcharging or reduced usage. The water level should be checked frequently from time to time. This article will discuss low water in car battery symptoms, reasons, and possible solutions.

Let’s start!

What Are The Low Water In Car Battery Symptoms?

When your car battery’s water level gets low, you’ll find poor performance from the battery. What happens if a car battery runs out of water?

Well, here’re few symptoms that you’d see when the battery is low on water.

Reduced Capacity

When the water level gets low which is below the top of the plates, you will experience reduced capacity.

Usually, the concentration of sulfuric acid is around 40% in a new lead-acid car battery. This electrolyte concentration balance is important for the optimal operation of the battery. Water level drops due to the continuous consumption to dilute the mixture and it results in increasing the acidity within the mixture.

So, when the battery is low with water, it would struggle to hold a charge for long and you’ll find the battery is constantly out of charge.

Slow Cranking

Your car battery cells utilize a reaction between lead and sulfuric acid to produce electricity that’d start the engine and power up electrical accessories. When the water is low, the concentration of acid increases and because of this, the reaction can’t generate the required amount of electricity which causes slow starting.

The vehicle takes much more time to start and delivers poor performance with the electrical components.


When the water in the mixture lessens, the plates are exposed to the air. When the electrodes come in contact with the oxygen of the atmosphere, corrosion builds up near the battery terminals.  

Why Is My Car Battery Losing Water?

While the alternator charges your car’s engine, it can overcharge the battery. Water depletes due to the overcharging of the battery.

The battery’s power is different to different ambient temperatures. For example, its power decreases when exposed to colder temperatures, while increased when exposed to average temperatures.

When the battery is heated up due to overcharging, it allows more current to flow through. This high current flow continues until the battery is fully charged. The excessive current flow would eventually cause a lessening of the water in the electrolyte causing the battery to die prematurely.

You can utilize the float mode and the ambient temperature control sensor of the vehicle so that the battery isn’t overcharged.

If you seldom use or even start the car, it may cause a decrease of water. When the car remains untouched for a long time, the battery starts self-deactivation. It causes a drop in the water level.

If the battery charger doesn’t match with the battery, it also causes reducing the water level. The charger may provide more or less amount of voltage than what’s required. So, you should use the recommended battery charger only.  

How to Add Water to Car Battery?

If you notice and act quickly, the battery life would be out of danger again. So, you should keep an eye on the battery and its performance frequently.

Here’re some steps that you can follow to keep your battery healthy.

Check the Battery

If you’re dealing with any of the phenomena that’re discussed above, wait no more to check the battery status. Most car batteries are accessible easily from the engine compartment. However, if you don’t find the battery location, look at it on the owner’s manual.

Clean the Battery Case

This is one of the most important steps that people often ignore. The case of the battery is filled with dirt and dust. Also, it accumulates debris. If you don’t clean the case before opening, the dirt may enter into the case and get mixed with the acidic mixture to make things even worse.

Open Porta and Check Water Level

Once you finish cleaning the case, open each of the ports and check the fluid level in them. The optimum water level is 1.5 inches above the plates. You must check and compare all the ports.

Refill with Distilled Water

If you find the water level is low, you should fill it with distilled water. The best water for car battery is available in most grocery stores. You may use a funnel while pouring water into the battery so that the water isn’t overfilled.

Can You Put Bottled Water In A Car Battery?

It isn’t recommended to use bottled or tap water other than distilled water as battery water. This is because the water of those sources may introduce contaminants to the mixture that’d decrease the battery life. As the best water for battery which is distilled water is free from contaminants, it’s safe to use.

Once you’re done with pouring distilled water, close the caps of all ports and keep the battery in its designated position within the engine compartment.

How Do You Know When Your Car Battery Needs Water?

To get the best performance, you should know when to add water to your battery. If you don’t know when water in car battery low, I have you back.

You can easily identify if the battery needs water by seeing a water indicator placed on the top portion of the battery. If the indicator shows green light, the battery has sufficient water. Again, if you see dark light, the battery needs water.

However, not all car battery comes with indicators to show the water level. If your battery doesn’t have one, you have to open the caps of all ports and check fluid status individually.

How Often to Check Car Battery Water Level?

Usually, it is recommended to check the water level of the battery every six months. However, if you overcharge for quite a long time, the water level drops even earlier.


Well, now you know low water in car battery symptoms, reasons, how to fix this issue.

I hope you enjoyed the reading and find this helpful. Thank you.

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