What Does a Battery’s Amp Hour Mean?

Every battery you buy is rated in a variety of different ways using an array of measuring systems. Unfortunately, many of these measurement systems can be confusing to consumers who aren’t yet well versed in batteries. One of the most important battery ratings to understand is its amp hour, which is often shortened to Ah. Continue reading to learn more about amp hours and what amp hour battery do I need.

What is battery Ah?

Amp hours (Ah) is the rating scale used to specify the capacity of sealed lead rechargeable batteries. The capacity of many sealed lead-acid batteries is determined under a constant current load, which, after 20 hours, the open circuit voltage to 1.8 volts per cell at 68°F. The load multiplied by 20 hours results in the amp-hour rating.

For example, a sealed rechargeable lead-acid battery or AGM battery with a rating of 7 Ah can provide 0.350 amps of power for 20 hours.

Where can I find the amp hour rating?

Amp hours might sound a bit confusing at first, but luckily, it’s an easy number to find. Assuming you’re looking at a rechargeable battery, the amp hour rating will be noted on the battery’s casing or the owner’s manual. If you can’t find its rating, you’re probably not looking at a rechargeable battery at all. Instead, you probably have a starting battery, which isn’t built to provide continuous power in the first place.

What is a battery’s discharge rate?

We can’t talk about amp hours without talking about discharge rate, commonly marked with the letter C. Discharge rate is the amount of time it takes the battery to fully discharge in one hour, so a battery with a discharge rate of 1C will fully discharge in one hour.

The capacity of a valve-regulated lead-acid battery varies in relation to the discharge rate. Higher discharge rates result in lower capacities available. The same 7 Ah battery discharged at 7 amps can provide 30 minutes of power, or only 3.5 Ah.

What amp hour battery do I need?

Now that you know how to read a battery’s amp hour rating, it’s time to get out there and purchase a rechargeable battery. Since a higher Ah rating typically means the battery will have a longer lifespan, we always recommend going with the battery that has the highest Ah rating.

The downside is that batteries with a higher Ah rating are typically more expensive to purchase, but if you’ll get more out of the battery, it’ll be worth the extra investment.

If you can’t decide which battery is best for your application, talk to our team at Texford Battery Co. Our pros will help you find the perfect battery, and we can even install it for you.

Let us recharge your batteries

In addition to selling the highest-quality batteries, we also specialize in recharging batteries. Bring your batteries to us today to have them tested and recharged. We’d even be happy to further explain what battery Ah is if you’re still a little uncertain!

Categorised in: Battery Store

This post was written by Writer