What is the internal resistance of a battery?

You might haven't heard about the internal resistance of a battery, but it is the opposition reaction to the flowing current inside the battery. Internal resistance has a strong effect on the working of the battery because they are somehow related. A battery shouldn't have an internal resistance, but it does have a limit; if the internal resistance crosses the limit, it will affect the battery's performance.

Low internal resistance means the battery carries a high amount of current.

A battery shouldn't have high internal resistance because it will affect it carrying current so it can get recharged. Therefore, it is necessary that the internal resistance of the battery to be normal, or you can say none at all.

Low internal resistance means the battery carries a high amount of current, which means everything is normal and your battery is perfectly fine. Factors can increase internal resistance and affect its capacity to carry current. Therefore, it is certain to maintain your battery and keep a check on the internal resistance. 

It would be wise to calculate the internal resistance of your battery to ensure that it doesn't have it or is at its normal limit. 

The Internal Resistance of the Battery Formula

You might be thinking about how you will know the battery's internal resistance. Well, you can measure it whenever you want. You just require the actual figures, apply the right formula, and you will know the internal resistance of your battery right instant. Well, it is a bit technical, but it will surely help you to know whether the internal resistance of your battery is at the right figure or if you need to do something to bring down the internal resistance right away.

The Formula: R=V-C

In this formula, R is resistance, V is voltage, and C represents current. Ohm's law formula is V=IR, but here we need to find the internal resistance, so you must change their place to find the answer you have been looking for. 

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Now you just have to subtract the current from the voltage of your battery to find the internal resistance. The normal internal resistance of a battery has to be zero, but if we talk about 12 volts car battery, it normally has to be 0.02 ohms. 

If the internal resistance crosses the normal limit, it increases and affects your battery performance. It would be a sign to take preventive measures to bring down the internal resistance figure. 

What causes internal resistance in a battery?

If the internal resistance of a battery increases, then the battery won't be able to carry a high amount of current. Internal resistance will affect its working. Therefore, it is important to ensure nothing increases the internal resistance in a battery. Here are a few factors that cause internal resistance in a battery, and it will keep increasing if you don't pay much attention to it:

Extreme Cold Temperature

Every battery that is available in the market comes with a temperature limit. Well, the temperature will directly impact the internal resistance in a battery. If the temperature gets extra chilly, then it will increase the internal resistance. So low temperatures are not ideal for your battery to work and get recharged properly. 

Grid Corrosion

Corrosion is surely the worst enemy of batteries because it will affect their performance, and to top it all, corrosion will increase the internal resistance of your battery. Therefore, you have to be very careful when it comes to the maintenance of your batteries. If you don't bother maintaining your battery, there is a great possibility that corrosion will start spreading, increasing the internal resistance to the point where it might die. 

Sulfation 

Sulfation takes place when your battery is deprived of getting fully charged, and it will build up and settles on the battery plates. If the sulfation keeps happening and settling in your battery, it will keep increasing the internal resistance of your battery. When the internal resistance keeps increasing, your battery will start decaying fast.

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So, it is very much important that you look for the signs of sulfation taking place in your battery. It will help you take the right preventive measure at the right time before the internal resistance makes your battery run out of any current. 

How to reduce the internal resistance of the battery?

A high resistance will harm the battery's current carrying capacity. Therefore, it is important to work on a few things that will help reduce the internal resistance so the battery will return to its best performance. Here are a few tips that will surely help in reducing the internal resistance of a battery:

Heating will help.

As we have mentioned above, low temperature increases the battery's internal resistance, and then heating will help decrease it. Yes, the temperature directly impacts your battery's internal resistance; therefore, you must try heating the temperature a little around the battery. 

If the temperature outside is quite chilly, ensure the temperature around the battery stays moderate, or heat it a little. The internal resistance won't increase if the temperature around it is optimal, even if it snows outside. 

Using Celluloid as Separators

Every battery consists of a separator for a solid reason. Yes, a separator gets installed between them to keep the ion moment in control from anode to cathode and vice versa. To decrease the internal resistance of a battery so it can carry the optimal amount of current, you can use celluloid. 

Yes, celluloid can be installed inside the battery to ensure that its internal resistance doesn't increase and affects the performance of a battery.

Final Words:

If you want your battery to work well, then it is very much important that the internal resistance of your battery is low. If it gets higher, your battery won't be able to carry a high amount of current and get recharged, as we have discussed the factors that will increase the internal resistance and a few tips to decrease the internal resistance effectively. So must act upon them; otherwise, your battery won't work properly for a long time.