Before the manufacturer fits a battery into the car, they match the power needs of the car with the size of the battery. The rating of car batteries is done by the number of amperes they can give for at least 30 Seconds at 00F temperature without the battery voltage falling below 7.2 volts.
The alternator will overheat and get burnt when you fit the car with the wrong battery. The wrong-sized battery will also get damaged and have a shorter lifespan compared it what it would have offered.
It is important to have the right battery for your car. It is worth noting that you can have 2 batteries giving 12 volts each but have different cranking amps.
What Happens If I Use A Small-Sized Battery?
Using a small battery means the power output of the battery is equally small. This means that your car engine might not get the required power for it to start and you will be left with no option to jump-start the car for the engine to kick off.
The electrical components of your car rely on the power from the battery to operate. When you use a small battery, which cannot provide power to have the gadgets on, it means you will not be able to have your AC on or even listen to your radio
When the battery you are using is too small, it might be getting excess charging power from the alternator that what it can tolerate. This will cause the battery to be overcharged. When it is overcharged, the following can happen:
- The battery will produce a lot of gases. Oxygen and hydrogen gases are produced as the battery undergoes electrolysis at a fastened rate.
- A lot of heat will build up inside the battery. As heat is built up, the inside temperature of the battery will rise and when it gets to a point where the battery can no longer contain, the battery will experience a thermal runway after which it will begin to melt, catch fire, or even explode.
- Electrolyte level will reduce leaving the plates exposed. This means that the materials which will be left for the electrochemical reactions to take place will be less and this equally translates to a lower battery capacity
- Corrosion at the positive terminal will occur. This corrosion will lead to the formation of a layer around the battery terminal. This layer will prevent the flow of current from the battery to the car and also from the car alternator to the battery.
- When the alternator gives more power than the battery can handle, the excess power is converted into heat. This excess heat in the alternator can lead to the destruction of the alternator.
- Electrical gadgets of the car and even the engine can fail to kick off
- The lifespan of the battery is shortened. When the battery has excess heat inside, its lifespan is reduced.
What Happens If I Use A Big-Sized Battery?
Most people would think that putting a big-sized battery in the car will solve most of their battery problems. However, this is not the case, and fitting your car with a big-sized problem will lead to the following:
- When you start the car engine more power than what the engine needs will be provided. The starter motor, however, may not be able to handle the excess current and will get damaged. This will send you back to your pockets to have the starter motor either repaired or replaced.
- The battery will provide excess power to the electrical components that what is needed and the electrical components will end up being damaged. Most of the electrical gadgets are designed in such a way that they don’t need much power to operate. When they are fed with higher currents than what they can contain they are likely to blow up.
- The battery may not get fully charged by the alternator. A partially charged battery will likely suffer from sulfation where the lead sulfate which is formed during discharge will combine with other lead sulfate molecules to have lead sulfate crystals formed. As earlier mentioned, these crystals are hard to break even through charging and this will drop the battery capacity and can shorten the lifespan of the battery.
- Corrosion at the negative terminal. This is always an indicator of undercharging. As the terminal corrodes a conductive layer is formed and this layer hinders the battery from passing current as it should. This means the battery is likely to discharge deeply and will remain prone to damage from sulfation.
- Damage to the alternator. Remember the battery is drawing more power than what the alternator is capable of providing this means the alternator will get drained and can heat up to the point of getting damaged. This will cost you to have the alternator repaired or replaced.
How Do I Know the Right Battery Size For My Car?
Physical inspection of the battery your car is currently using will help you identify the right battery size for your car. You will then need to look at the label which is on the side of the battery that you want replaced.
At the label, you will be able to know the reserve charge, voltage, and rated cranking amps. The user’s manual of the battery and the car can also guide you.
Some cars have the battery information indicated on the battery chamber as an engraving on the battery plate holder or as a sticker. In a case where you are not sure of the battery size to have fitted in your car, you may consider having a mechanic to advise you.
Final Thoughts
A car battery can lose up to 40% of its cranking power and will still be able to provide sufficient power to the starter motor to have the engine cranked.
This implies that even a battery that has a cranking power that is 40% less the original will still be able to have the engine cranked however small the battery might be.
As we have mentioned earlier, due to problems like overheating, the battery will probably not last longer.