How to Calculate Amp Hours – Convert Watts to Amps

Nothing is more fun than to spend your weekends off by doing boating and fishing activities. It is a great way to shake off the stress after a week of work, and it is also a great way to escape the hustle and bustle of city life.

However, in doing these kinds of activities, you must equip yourself, especially your boat, with necessary tools, motors and equipment such as a reliable marine battery to ensure you have a fun, stress-free and fulfilling water activity. 

In addition, you must also make sure that the battery for your boat can be of best use for you, that is why it is important for you to know how far it can go. Thus, this article will help you how to calculate amp hours on your battery so that you will know how far it can be of use during water action. In addition, we will also teach you what are amp hours, and how to calculate amps from watts.

how to calculate amp hours

What Does Amp Hours Mean?

A battery’s amp hours play a vital role in helping you know how long you can do your water activity. There may be times you might ask: “What is an amp hour?” or “What is amp hours and why do I have to take note of it?” Well, we will provide you the answer.

A marine battery’s amp hours act as a guide for you to learn how far it can go before it gets discharged. Commonly abbreviated as Ah, an amp hour is the energy amount of your battery which allows 1 current amp to flow for an hour.

There is a need for you to take note of your battery’s amp hours for you to know how long it could be of use for you, so that you prepare beforehand and you can avoid being stranded on water. However, one thing you must consider more is the amount of amp hours your battery has; the longer the amp hours, the better.

How Many Amp Hours in a Marine Battery

Most marine or deep cycle batteries in the market have labels which indicate how much amp hours they have. Generally, a battery with a low amp charge of around 2-4A can be used for 8-12 hours. However, that is still dependent on the battery’s condition.

For you to have a grasp of how many amp hours does a marine battery have, you can use this illustration. Supposing your marine battery has 210Ah, and it has a 20-hour discharge rate. Divide 210Ah by 20, and that will give you 10.5 amp hours of available power until the battery is discharged.

However, it is highly recommended not to discharge the battery all the way down to 0, because it can affect its functionality. Thus, if possible, just use 50% of the battery’s capacity to prolong its useful life.

How Do You Convert Watts to Amps?

Technically, you can’t convert watts to amps because of the fact that watts are power and amps are coulombs/second. However, if you include volts in the picture, it is possible to convert watts to amps, because watts are product of amps multiplied by volts.

To convert watts to amps by using volts (i.e.12V), you can use this equation:


Thus, if you have 24 watts and 12 volts, the answer is 2A.


In addition, you may ask, “How many amps is 1000 watts?”

Let’s say the energy involved in this calculation is 24V, so:


Therefore, a motor/machine with 1000W power and 24V energy has approximately 41.67 amps.


With these essential information about how to calculate amp hours, how many amp hours does a marine battery have and how to convert watts to amps, you now have knowledge you can greatly use especially at times when you have to calculate your trolling motor batteries amp hours because it is not indicated somewhere in its package. Thus, with this information, you will know what to do with the concern at hand easily and stress-free.

Always equip yourself with the things you will need and the knowledge you can use for you to have a fun and fulfilling experience in every boating and fishing activity. Sail on!

Read more:

About This Writer

Liam Jaxon Author pic

Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.

Guys, I am Camila Avery and I love to help my mom to do indoor & outdoor activities. As a lady, I have passed my time on gardening, home improvement, and personal or self-care. I have acquired some degrees in outdoor recreation, beauty, and hair care. It is not easy to work with top-level professional beauty experts. But, I got that opportunity and experimented with different hair extensions, hair colors, and cuts.

Leave a Comment