Instructables

What Battery Brand Provides Power the Longest?

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Picture of What Battery Brand Provides Power the Longest?

In this age of ubiquitous electronics, batteries have an astounding importance in our everyday lives. As we buy and use different brands, we come to wonder, "Which of these is actually the best? Is it worth it to go for a big name brand?" To answer these questions, I set up an experiment to test the endurance of four different battery brands: Duracell, Energizer, Rayovac, and Sunbeam(a dollar store brand).

 
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Step 1: The Materials and The Hypothesis

Picture of The Materials and The Hypothesis

To test the comparative endurance of the four battery brands under study, I used four Mini Maglite xenon lamp flashlights purchased from Walmart on the same day. As for batteries, I bought an eight pack of Energizer AA batteries, an eight pack of Rayovac AA batteries, and a four pack of Sunbeam dollar store AA batteries. The flashlights came with Duracell, so I used those batteries for the Duracell test. I did, however, find a price for a Duracell eight pack in order to compare prices more effectively in the conclusion.

My hypothesis was as follows: Dollar store batteries will be the first to go, with one of the bigger name brands coming out on top. I had no basis for distinguishing between the three top brands, but because the Duracells came with the flashlights, indicating that they might be preferable, I hypothesized that Duracell would last the longest.

Step 2: The Setup

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To carry out the actual test, I prepared an apparatus that would hold the flashlights parallel to one another, all shining on one piece of cardboard so their relative intensities could be observed. I put two Sunbeam batteries in the top light, two Duracells in the second, two Energizers in the third, and two Rayovacs in the fourth.

Step 3: Starting the Test

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To start the flashlights, I went from top to bottom, twisting the top of each light until the exact point at which the light turned on (the flashlights were turn-top instead of push-button. Button flashlights may be more useful in future experiments). In all, going from Sunbeam to Duracell to Energizer to Rayovac took 13 seconds.

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Lorax982 months ago

You have not only determined the value of various battery brands, you have also given an A+ demonstration of the scientific method!! I will be using your Instructable as an exemplar for my grade 9 science students.

DIYnosaur (author)  Lorax982 months ago

Wow, thank you very much for the compliment -- I am quite honored that my project can be used as an educational tool!

osh1142 months ago

I find this experiment very educational and very helpful for all. This experiment is worth my vote because it not only is simple but it is very practical for all that read it. Great job and keep up the good work!

Bill WW2 months ago

Nice work, great test!

Yes you could do all those things suggested in the comments. But your test is fine as it is. You explained the limitations.

I have done the current draw test with large 12v boat batteries, plotted charts, made comparisons. You can drive yourself crazy measuring, considering all kinds of variables. What you did was very clear and concise.

DIYnosaur (author)  Bill WW2 months ago

Thank you very much for the compliment and the comment! I know what you mean by all of the tests driving you crazy - just thinking about all of the possiblities and variables was enough to boggle my mind.

Teachable13 days ago

Nice. I buy Rayovacs but thought they probably weren't as comparable as they claim they are to the more expensive brands, nice surprise.

zoomtronic11 month ago

excellent

bryanep1 month ago

Loved it Thanks!

jlsmoothash2o2 months ago
I see some really big problems with your test.

1 what was the mAh of your batteries. Different Amps values will change the outcome of your test. They need to all have the same mAh.

2 Manufacturing date of the batteries. The longer they stay on the shelf the more power loss they will have. Batteries will give you an expiration date some will give you the date they were made. But if you use the expiration date make sure it is the same month and year. This way you know that they were more than likely made close to the same date or at least they have the same life left in them.

3 I would have used 4 different stopwatches so each one has its own time running this way you do not have to worry about the time from the first one on to the last one on time.

It could be argued that variations in mAhs was what diynosaur was testing.

From what I understood from his statement was he was looking for the best quality of battery for the price. So if your going to do that then you really need to have the same mAh on all the batteries. The reason is if the dollar store batteries were of a lower mAh then the name brand batteries it is not a fair comparison. I know that each of the name brand batteries he listed sell them in different mAh. Each mAh rating has a different price point. Which is why you really need to have the same mAh rating.

But note the step where he divided each one by the time it actually ran. If you assume that each flashlight bulb has an identical resistance and given that the voltage should be the same, and thus that the draw on each battery is identical, than the rate of drain (milliamps) is identical. So by dividing the price by the time it ran, he is measuring how much it costs per hour at a fixed rate. i.e. the cost per milliamp, per hour, otherwise known as the cost per mAh, without having to trust what the manufacturer claims. If you did have them all be the same mAh rating, and if the ratings really were right, then all the batteries would run down at the same time. And then you would just need to look at the price to know. The only value in having all the mAh ratings be the same would be to prove if any of the manufacturers were wrong/lying.

Jerz mkanoap1 month ago

A batteries capacity vs output isn't perfectly linear as it is scaled up. A 2400mAh battery will usually perform more than twice as long as a 1200mAh battery on certain loads. I think that's the point that jlsmoothash2o was trying to make. As the load gets closer to the batteries rated output, its' efficiency changes in a non-linear fashion.

mkanoap Jerz1 month ago

That's a good point. But still, in the end of the experiment, DIYnosaur ranked the batteries by cost per hour of useable light. Thus empirically cutting right to the actual cost of powering these flashlight with different batteries. Ignoring of course all the costs of having to lug all the extra batteries around or to change them when the grue is closing in.

Starting with all batteries with the same Mah rating (if you could find them) would be an interesting experiment, but not a requirement for learning what was learned. So I do not thing there were "big problems" with the test.

I guess it depends on what you think the test was determining.

It is true that if you ran the same experiment with different loads, you might find that other batteries are more cost effective for a particular job.

aseavey2 months ago

very nice test. I did this for a middle school science fair project. using Duracell rayovac and energizer. my test was only slightly diffent as I had 3 flash lights for each brand. and I myself got the same results. all my batteries were produced approx the same time frame from what I could tell by the expiration date. this test was almost 10-12 years ago but none the less nice to see the results are still the same.

shellyscorner2 months ago

Hey! You did a GREAT job! Honestly, I'm actually not even surprised at the results. And FOR ALL the "ARM-CHAIR QUARTER BACKS" with ALL the suggestions of how the test should be redone and ALL the things that SHOULD have been considered ..... How about all of YOU guys "RE-doing" the test and let the rest of us know how it turns out! Well done and well documented!

lifeinbeats2 months ago

I agree with others that there needs to be more of a sampling. There are quite a few variables here. Age of battery, quality control of battery company and differences in flashlights pop into my head. It'd be interesting if you were to do this several more times, buying new batteries (all with the same date), and switch up which flashlight contains which battery. That should rule out all of the variables I mentioned above.

SIRJAMES092 months ago

AWESOME!

very educational, & very enjoyable read!

TY for posting this & TY for all the work it took to make this. :)

samuraijack2 months ago

really informative and very well executed.

bravo my friend.

Radicalone2 months ago

Great job!

nehmo2 months ago

What chemistry was the Sunbeam? It appears the others were Alkaline, and the sunbeam was Zinc/Carbon in an Alkaline labeled wrapper. Considering Sunbeam doesn't really make them, I wouldn't be surprised. Someone please cut them open and post the results.

The test only used one type of load, a constant resistance of one level. There is much more to Battery comparison than that. Shelf life is also a consideration, for one thing.

khearn2 months ago

I agree with jlambert that using the Duracells that came with the flashlights might not have been a good idea. They may be older, given the extra steps in their distribution. Plus, it wouldn't surprise me if the batteries distributed with flashlights are different than the batteries sold separately. I know that the ink cartridges that come with most printers have significantly less ink than cartridges that are sold separately. They may also sell lower capacity batteries in bundles to keep prices down. I don't know that they do, but it would be worth testing.

cyberdove2 months ago

Did all the batteries have the same expiration date?

patsheldon2 months ago

Nice, thanks for the money saving tip!!

jobard2 months ago

I have a question. Did you consider the expiration date of each battery? If for instance Sunbeam will expire in Aug.2017 and Energizer in Jun.2019, then, theoretically the latter will last longer.

dropkick2 months ago

Great Instructable. Thank you for doing this work and providing us with the information.

cybercapri2 months ago

Well done and the winner was a shocker, won't say who won and spoil the surprise, but it changed my mind... I voted for you and hope you win...

jkarouta2 months ago

Hey, I found your instructable very nice and useful, however I found it slightly regrettable that you did not set a benchmark. Even though you used same flashlights, they might differ quite a lot in power consumption, and the difference between the last two batteries could be due to side-effects and not to the average battery lives. If you would do a similar test in the future, first try to do a benchmark test by filling all your products with the same batteries (one could even argue that the more expensive ones should be used here, as they would have the least inter-product difference). According to that result you can make an estimate of the true battery life. Also you could redo the test with only the winning two, with interchanged flashlights. The underlying message here is that there are a lot of issues that influence a test, and taking into account everything is difficult, if not impossible, but it's always good to try to avoid side-effects affecting the results as much as possible Nevertheless keep up the cool and good work! :)

jlambert2 months ago

You should have given Duracell a fair shake by buying fresh pack instead of using ones that came with flashlight. I've done similar test between Duracell and Entergizer and have been using Duracell ever since

ElectroFrank2 months ago

A very good (and very practical) test. But to rule out variations
in battery performance due to variations in bulb resistance, it would be
good to have a fixed resistance and measure the battery's voltage and
the actual circuit current with test meters. (For this application,
analog meters would be good, to avoid running down a digital meter's
battery over several hours.)

Then graph the results, and you can calculate the capacity in Ampere-hours of the batteries (running down to a certain % of the nominal voltage).

Personally,
I think all batteries should be clearly marked with their capacity,
using a standardised test, so that we can all make an informed choice.

Advertising claims about one brand being six times better than "ordinary"
batteries are nonsense, as there are many different types of "ordinary"
batteries, and it is fraudulent to thus compare different types.

ElectroFrank2 months ago

A very good (and very practical) test. But to rule out variations in battery performance due to variations in bulb resistance, it would be good to have a fixed resistance and measure the battery's voltage and the actual circuit current with test meters. (For this application, analog meters would be good, to avoid running down a digital meter's battery over several hours.)

Then graph the results, and you can calculate the capacity in Ampere-hours of the batteries (running down to a certain % of the nominal voltage).

Personally, I think all batteries should be clearly marked with their capacity, using a standardised test, so that we can all make an informed choice.

Advertising claims about one brand being six times better than "ordinary" batteries are nonsense, as there are many different types of "ordinary" batteries, and it is fraudulent to thus compare different types.

lesizz2 months ago

Nice experiment. I have done similar experiments with AA NiMH and on 9 volt batteries including alkaline, lithium and lithium ion.

As I was reading through your i'ble I was watching for a disclaimer statement that you posted under "Worth a Note". From a scientific standpoint, that is one of the most important parts of the report: The limitations of the test.

Other conditions are temperature; different brands may respond differently to extreme temperatures. If you wanted to get really down n' scientific, you'd test multiple samples of each product and check on the manufacture dates of each.

But of course you are not a lab, and your tests provided valuable info as far at they went.

Another factor (this can get so complicated): I just got a batch of AAA Rayovac alkalines from Costco, and on the package was stated a guarantee that the manufacturer would pay for damages to devices due to battery leakage. So that could affect the overall cost of a battery too.

shortw2 months ago

Very nicely done.

At least someone can see the difference in battery output per brand and how much money it will cost to operate an flashlight.

razamatraz2 months ago

Also might want to test the initial and "under-load" voltages. Slight chemistry variations could result in slightly different voltages and of course power scales with the square of the voltage.

razamatraz2 months ago

A good start, now rotate which flashlight has which battery type in them and do it again. Bulbs are close to the same but even a tiny difference in the filament can change how much power they use in operation. I suspect this difference is not enough to bring the first one out to the top but might be enough to make the difference between #1 and #2 insignificant.

desidude522 months ago

Excellent experiment and instructable! Conclusion was super clear. It would be really cool to see this experiment done with camera flashes instead of flash lights. As a photographer this could be cost effective information :)

The phenomenon you experienced after the batteries had died and then worked again afterward is called surface charge. It's inherent to chemical storage of electricity. This is the reason why when you get your cars battery tested it is VERY important that they do a "load test" rather that just stick a voltmeter on it to see if there is 12 volts.

Here's a longer explanation if you're curious - http://www.smartgauge.co.uk/surf_chg.html

No, he was replacing the dead batteries with NEW batteries to make sure the bulb wasn't burnt out.

Nooooope. While he did do as you described, he also mentioned breaking the circuit and then completing it again which produced a faint glimmer before "being dead" again.

The surface charge description is accurate. However it's not a huge deal with alkaline batteriesbecause they simply end up dead.

With rechargeables you'll get a decline in capacity over time due to chemical changes on the anode and cathode.
DIYnosaur (author)  Nexus of Crisis2 months ago

That is very interesting, thanks for sharing the info!

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