There is a very common misconception that a higher AH is always better and supplies more power. Although it is partially true, it is not exactly right under all conditions. So, we’ll walk you through the science behind a battery and figure out how or how not is a higher Ah battery better.
Is A Higher Ah Battery Better
For batteries, an ampere-hour is a unit of measure for the capacity of a battery. It refers to the runtime of a battery. Theoretically, A higher ampere-hour means that the battery can sufficiently deliver the same amount of power as a lower ampere-hour battery but for a longer period.
Now, whether a higher AH battery is better or not depends on the necessity and the function of the tool. Let’s quickly go through the advantages and disadvantages of a higher AH battery to find out if they are in fact superior.
In definition, the ampere-hour refers to the capacity of a battery. You can think of it like a gas tank where the larger the tank is, the more fuel it can hold. Similarly, with a higher AH rating, you’ll get a longer runtime without having to recharge the battery.
However, it also means that a higher AH battery would take longer to recharge. So, a 4 AH battery would approximately last twice as long as a 2 AH battery, but it would also take twice as long for the 4 AH to recharge.
Power Supply and Runtime
A battery is a combination of cells. Usually, there are 5 cells connected in series in a 2 AH battery and 2 parallelly connected rows of 5 cells in a 5 AH battery. Finally, the cells combine to supply power for the battery. Here, although the AH rating refers to the runtime, the number of cells affects the power supplied by it.
Both 2 AH and 5 AH batteries should theoretically supply the same amount of power. Assuming a tool requires 360W of power, for an 18V-2AH battery, the 5 cells have to supply the 20 amperes of current to meet the required supply. But for the 5 AH battery, the 10 cells combine to supply the same 20 amperes of current.
Now, each set of 5 cells have to supply only 10 amperes of current. Thus, it is easier for the 5 AH battery to keep the power level up. So, although a 4 AH battery should have exactly twice the runtime and power of a 2AH battery, in practical use, a 4 AH battery delivers slightly more than the theoretical approximation.
In case you are using the battery for an off-grid supply, it is better to get a higher AH battery. This is obvious since a higher AH battery can support loads for a longer period. And being able to get power for a longer period ultimately increases productivity.
Furthermore, getting a higher AH battery for cordless tools also increases productivity. In recent years cordless tools are being greatly used for both DIY and professional uses. In addition to that, a higher AH battery enables them to be used uninterruptedly for a longer time.
The durability of a battery depends largely on the number of times it is charged and discharged. As a higher AH battery has a larger capacity, it doesn’t need to be recharged frequently. Thus, a higher AH battery has longer durability compared to a lower AH battery.
Weight and Size
With the advancement of technology, life is impossible without electronic gadgets. And as each day goes by, we are getting closer to a world where wires don’t exist. Even today, most gadgets are largely dependent on batteries for power. This is where weight and size comparison comes in.
As a higher AH requires more cells, it becomes heavier and requires more space. Although you get better performance, you need to make sure your tool can fit the battery you are getting.
Does A Car Battery Replacement Have To Be The Same AH
According to most experts, as long as the voltage is similar or somewhat near, a higher Ah should be fine for a car battery replacement. AH rating just determines the time your battery will last without recharging. So, if your alternator can support the replacement AH, it’s fine to go higher than the existing one.
However, a much higher Ah rating is most likely to cause slow charging and load on your alternator. So, staying closer to the previous AH rating is crucial as well. Also, higher AH batteries tend to be larger and heavier so they should be able to fit your car as well.
Frequently Asked Questions
- Can I use a 4AH battery instead of a 2AH battery?
Ans: Yes, you can use a 4AH battery but you need to make sure your device can fit the larger battery.
- Does a higher AH battery give more power?
Ans: Theoretically, a higher AH battery should give the same power as a lower AH battery but in practical use, a higher Ah battery delivers slightly more power than the lower AH battery.
- How long does a 4 AH battery last?
Ans: A 4 AH lasts approximately 35 to 45 minutes on one charge. Although this depends on the requirement of the device as well. You may have a look at the complete cordless tools battery guide.
From what we can see so far, it is undoubtedly better to get a higher AH battery if you want more capacity and power. But power and capacity come at the expense of weight and volume. If weight is not an issue, you should definitely get a higher AH battery.
Related article: Various types of battery charger