Can You Overcharge A Car Battery?


Car Battery runs out of juice and it is important to charge them when it does. During the time you do that, you need to be careful so that you don’t ruin the life of the battery. One of the most consequential things you must take into cognizance is not overcharging the battery.

New car owners always encounter this problem because they are still trying to get the hang of maintaining a vehicle. Unfortunately, modern car batteries are built in a way that their exploding potential is low. However, there are always other signs that explicitly describes an overcharged battery – they are sometimes unnoticed until the battery gets so bad.

So, Yes, you can overcharge a car battery.


What Happens In An Overcharged Battery?)

If a car battery gets charged beyond the standard limit, a chemical reaction takes place within its system. Significantly, batteries contain acid – hydrochloric or sulfuric acid; the acid constituent gets boiled and mixes with the distilled water. In the process, flammable Hydrogen builds up inside the sealed fuel cells. On exposure of the Hydrogen to Oxygen, the battery becomes dangerous (a sitting time-bomb); a small electric spark could make it go up in flames. During this reaction, the battery case becomes too hot and starts to swell and melt. The air around also gets bad and choky, while it sends toxic lead-laced shrapnel to every angle and sprays caustic sulfuric acid around.

What Causes an Overcharged Battery?

Now that you know what happens within the framework of a battery when it gets overcharged, what do you think caused it? It could either be mechanical or human error. The mechanical error could be a result of the internal voltage regulator, called Alternator designed to charge it for active operation. On the other hand, Human error could be setting incorrect voltage and purchasing poor quality battery chargers. Whatever it is, the overcharging of a battery brings the same result.

Generally, there are about 5 cases, and they are;

  • Broken/Bad Alternator

Alternators are designed to provide a car battery with the needed energy for performance. It generates electricity in which the car uses to run different appliances, such as stereos, lock mechanism, lights, AC, etc. In a situation where the alternator goes bad, the energy produced becomes jeopardized.

Most times, a broken or bad alternator causes the battery to overcharge. However, it comes with other symptoms such as the poor response of electrical systems, problematic and sluggish ignition of a car engine, and so on. What causes a bad alternator, on the other hand, is a bad voltage regulator. Therefore, you need to fix all these components; see how the battery responds after the fix.

See here on Bad Battery Symptoms.

  • Broken Voltage Regulators

In a car, electricity is produced by a component called the Voltage Regulator. This electricity is used by the Alternator to power the battery for work. As mentioned earlier, when this regulator breaks, the electricity produced becomes affected – could be little or much. It further affects the working operation of the alternator, and ultimately, the battery. Therefore, if you have an overcharged battery, there is a good chance that the energy dispensed is too much than the alternator can handle.

  • Extreme Heat

Before now, it is believed that weather affects battery life. In the situation of an overcharged battery, extreme heat could be responsible. When the battery is exposed to the sun for so long, it gains too much heat that could affect its functionality. This high temperature could charge the battery more than normal, and eventually get damaged. What you should do is remove the battery when not in use, during this period, and keep it in a place with good ventilation.

  • Battery Charger Misuse

If you are new to using a car, many things could go wrong if you aren’t careful. At different times, you will find yourself doing the wrong thing and that could affect your car and its components. One of those things you will find a bit difficult is using a car battery charger. There is no proper way to handle it; however, you have to rely on instincts. As a newbie, you may not know all that and could end up undercharging or overcharging a battery. It would be best if you hired the services of a mechanic instead of doing it all by yourself.

  • Bad Battery Charger

Battery Charger problems aren’t only with newbies; even professionals aren’t left out. A faulty or bad charger could affect battery life. For instance, if you don’t make the proper wire connections or label the charges correctly, there is a good chance that it would either undercharge or overcharge a battery. The amount of electricity being altered could cause serious problems eventually.

How to Check a Battery that is Overcharged?

Car batteries are one of the largest sets of batteries with high voltage. Most modern cars that use alternators run on a 12V battery; now, when you overcharge the battery, the voltage runs higher. Sometimes, you will find a fully charged battery at 12.6V. When it ranges between 13.6 to 14.6V, then there is a problem.

It is easier to read new batteries than used ones. Likewise, new battery chargers that are effective might be able to tell the voltage coming from a battery. If you cannot access a battery charger like that, then a multimeter would be perfect.

Why Do You Need to Charge Your Battery?

Do you wonder why you need to charge batteries, especially for cars? Well, it is because Car batteries contain Lead-plated internal cells with Distilled Water and Sulfuric Acid around it. As time goes by, Lead sulfate is deposited on the plates; it eventually turns to crystal. This crystal affects the charging potentials and power-holding capacity of the battery. The process is called Sulfation. However, constant charge and discharge would limit Sulfation and maintain battery life longer.


Can You Overcharge A Car Battery after reading this article? Yes, you can. It is a bad thing to do, which is why it has been explicitly discussed above on what causes it and how to prevent the situation. In conclusion, with a good battery, there is low maintenance on your car.