Which Battery Lasts The Longest for Science Fair Project?

We must have experienced the time when we are looking for our flashlights during a blackout and when we find it, the flashlights do not work. There is also another situation when the clock at our home is not working all of sudden. Both cases are caused by dead batteries. When it happens, the only thing we can do is change it with the new one.

It is not unusual for us to watch batteries advertisements that claim their brands as the best ones. Every battery company claims that their product is the most durable among all the other brands in the market. But, which battery lasts the longest? Here is an experiment you can do at home or even at a science fair project.


Which Battery Lasts The Longest for Science Fair Project?

Knowing which battery lasts the longest might sound like an unnecessary thing, but it actually will help us a lot. We need batteries in our daily-life appliances, starting from the remotes for TV and AC, flashlight, clock to batteries-based toys. Once we know which battery lasts the longest, it will help us to make an efficient choice of batteries.

This is a very simple project that can be presented in a science fair. Here are the materials you need, instructions, and some questions to be observed during the project.

  • Materials

These are very simple materials. You can easily find it at your home

  1. Four different brands of batteries
  2. Four identical flashlights
  3. A small piece of cardboard
  4. A masking tape (for labels)
  5. A marker
  6. A notebook
  7. Timer/clock

Flashlights are usually required two pieces of AA batteries. To choose which brands of batteries for this project, you can choose four different brands that show a range of price. That way you can see if there is a correlation between the price and the durability of the batteries. Is the most expensive battery is the one that lasts the longest?

Another thing you have to pay attention to the batteries you are using in this project is to make sure to use both alkaline and non-alkaline batteries. When fresh, both Alkaline and non-alkaline batteries have the same voltage 1,5. But, the alkaline has a higher capacity than non-alkaline. Let’s see in the result which type of batteries lasts the longest.

You also need to make sure that the flashlights you are going to use are the ones that have power settings. There are usually three kinds of setting, they are high, medium, and low. It is important because it will determine the time needed for the observation.

  • Instructions

Here are the steps you must follow during the project:

  1. Write the name of each brand on each of the masking tape, as well as the type of each battery (alkaline or non-alkaline) and stick it on each of the flashlights.
  2. Put the batteries into the flashlight based on the label
  3. Put the cardboard in front of all three of the flashlights. That way, when you turn on the flashlights, you can easily observe the light by looking at the surface of the cupboard.
  4. Turn on the flashlights on its highest setting at the same time and write the time on your notebook. When you start the time, you can also write down if one of the brands produces the brightest light.
  5. During your observation, you also need to note which brand starts to dim first.
  6. Make sure to record the time of each brand when its flashlight goes out.

This observation will take you approximately 1,5 until 7 hours. That is why, as mentioned above, turning on the flashlights on the highest setting is one of the major keys you must remember on this project. You will spend more time if you turn the flashlight on its lowest setting.

Since there is a possibility you will spend up to 7 hours on this project, make sure you choose the right time to start it. You have to check in advance that during this project, there will not be any distraction that is going to hold you up.

  • Results

After all of the flashlights are dead, you will find that there is no correlation between the price of the battery and its endurance. Paying more for your battery does not mean you will get the battery that lasts the longest.


You will also find that alkaline batteries last longer than the non-alkaline ones. This is because the capacity of the alkaline batteries is higher than the non-alkaline. The battery produces current to make our appliances function.

Current is the product of the chemical reaction, where the chemicals contained in the battery turn into the current. The more chemicals a battery has, the longer it lasts. That is why you will find that alkaline battery last the longest.