How to Read and Choose Correct Battery Size For Your Vehicle

 The size of your car battery and selecting the correct battery for your vehicle's make and model are critical. If you choose the wrong one, your car will not work as it should or may, regardless of its specifications or how well it is maintained.

The spark that ignites the fuel that gets you started is powered by your car battery. It also assists in providing power to your lamps, indicators, navigation system, dash-cams, windscreen wipers, and electric windows, as well as a variety of other on-board electrical features.

Car batteries have a three to five-year average life span, assuming they're the right size for your vehicle; the wrong size can lead to unreliability and frequent breakdowns.

The size can prefer to physical size of batteries. But we often difficult to different each batteries because it has similar size.

But, the container of battery of course different.

There are two things that refer to battery sizing.

1. Battery Amp Hour

The amperage hour rating is used to tell customers how much power a battery will supply for one hour. The amp hour rating is typically provided in milli-amp hours, or mAh, in small batteries such as those used in personal vaporizers or regular AA sized batteries (mAh).

The ranking for large batteries is abbreviated as Ah. The Ah level of most deep cycle batteries can be seen at several C ratings. The C rating indicates how many amp hours the battery will deliver over a given time span. For example, a battery at C/5 could safely provide 26.8 amp hours. This means that it can supply 26.8 amps for 5 hours without shutting down..

In the meantime, the same battery could safely provide 36 amp hours for 100 hours. You'll want to compare amp hours with different C ratings depending on how much usage you plan to get out of your battery (daily vs sporadically). If you're not sure which C rating to use, the C/20 is the best choice. The C/20 is the middle ground, it will give you a general sense of battery performance.

The amp hour rating of a battery can be calculated by multiplying the current (amperes) by the discharge time (hours). Alternatively, if we know the battery's amp hour value, we can calculate how long the battery can last when providing a certain current.

Current (I) = 10 amperes ; Discharge Time (T) = 15 hours

Therefore, this battery would have an amp hour rating of :

Amp Hour = Current (I) x Discharge Time (T)

Amp Hour = 10 amperes x 15 hours

Amp Hour = 150 Ah

Rating = 150 Ah @ 15 hours

It mean, the battery will last for 15 hour on 10 amp discharging. If the discharge current is higher, the time will decrease. From this, we know that higher AH rating mean longer the battery last.

2. Cold Crank Amps (CCA)

The most common industry rating is CCA (Cold Cranking Amperes), which is a calculation of the current a fully charged battery can produce for 30 seconds while maintaining a voltage of 7.2 volts (12 volt battery) at -18°C.

CCAs are significant, but they aren't the best metric for hotter or more Australian conditions. They're the ratings that the battery industry uses to describe a new battery's capacity to start an engine in extremely cold conditions, and they're more applicable to the North American and European markets.

The CCA rating is more important if you live in a cold environment than it is if you live in a warm one. Since the starting power of a battery decreases as it ages, a battery with a higher starting power can provide you with more faith over time.

Replacement batteries should have the same or higher rating than the original battery. When you replace a battery with one that has a lower CCA than the original, you risk getting poor results.

But the amount of CCA doesn’t mean positive to all vehicle. Now, the vehicle has advanced starting technology. So the engine start load is reduce. So the excessive amount of CCA is non a factor that makes the battery good to choose.

It's difficult to choose the best battery for the vehicle or application because there are so many similar-looking black batteries on the market claiming to have the highest CCA scores.  

Given the negative effects of higher CCA on overall life and a vehicle's starter motors, it's important to know what the vehicle is used for and the operating conditions (including temperature) before choosing the best battery.

Don't be deceived by big CCA figures. The trick to selecting the right battery is to choose one with design features and internal components that are better suited to the vehicle's requirements and operating conditions.