I tested Energizer batteries. Don’t fall for the bottle

That’s why I initially decided to focus on batteries from one manufacturer. I chose Energizer. I took three, or actually four, batteries marked as: Energizer Longest Lasting 50%, Energizer Max Longest Lasting 100%, and two Energizer Max Plus Longest Lasting 200%. What do these numbers mean? I have no idea.

And it’s not that I haven’t tried to find out what exactly that means: quite the contrary. I decided to contact Energizer. The only option was to ask a question via the contact form, which I did. After a few days, I even received a reply which, after translation, reads as follows:

Thank you for contacting Energizer. We are glad that you are interested in our products. Please click the link below to contact the support team in your region. If you have any questions or concerns, please reply to this email for further assistance.

The link in question led to… the contact form from which I wrote the first message. Of course, I replied to the email, but I’m still waiting for a reply.

Let’s assume, however, that we are talking about a basic Energizer Industrial alkaline battery, which we were unable to buy, and one of which performs 50% better, the second 100% better, and the third 200% better. In this case, Energizer Max should do 33.(3)% better than Energizer 50%, and Max Plus should do 100% better.

NiMH, Li-ion and Li-Po batteries should be checked with a current C of 0.2. C, on the other hand, means the declared capacity expressed in ampere-hours. Thus, we discharge a 1000 mAh battery with a current of 0.2 A, i.e. 200 mA. The problem is that no one provides the declared capacity for alkaline batteries.

Does this matter for the test? Well, absolutely. To put it very simply: the lower the current we discharge the cell, the greater its capacity. However, it is also important that the current is high enough so that tests of one piece do not last several days. What to do in such a situation? Well, I once read that the Game Boy Advance consumes from 70 to 100 mA. So I took 100 mA as the test value. As for battery discharge, I assumed a drop in battery voltage to 0.9 V, which is the level at which they are generally considered discharged.

It is also worth emphasizing that the unloading took place continuously, without breaks. In the case of alkaline batteries, this is also very important and continuous operation has a negative impact on their performance. But remember that all of them were treated the same way. I also bought all of them in one day in the same store.

We managed to squeeze 2332 mAh out of it. However, remember that this value refers to the constantly decreasing voltage, so it doesn’t really tell us much about how much energy we have extracted from it. As for this one, we managed to squeeze 2.82602 Wh out of it. Is that a lot? Well, a typical 1000 mAh lithium-ion battery is 3.7 Wh. What about working time? Well, the result achieved is 23 hours, 19 minutes and 7 seconds.

That is, a battery that, according to the markings on the packaging, should be 33.(3)% better than its predecessor. Is this the case in practice? Well… the achieved capacity is 2431 mAh. We managed to obtain 3.02026 Wh from it, and it worked for 24 hours, 18 minutes and 33 seconds at a power of 100 mAh. Yes, it is a better result. The problem is that in terms of capacity, expressed in mAh, we saw a jump of 4.25%, in watt hours – by 6.87%, and in operating time – by 4.4%. The difference is therefore small and there is no mention of an increase of 33(3)%.

Here comes another problem. During the first measurement, the results turned out to be slightly worse than in the case of Energizer Max Longest Lasting 100%. We are talking about a capacity expressed in mAh of 2428, 3.05781 Wh and an operating time of 24 hours, 16 minutes and 14 seconds.

What could I do in this situation? Well, I went to another store to avoid buying batteries from the same batch and repeated the experiment. What is very important: both packages declare an expiration date of 12/2040. Well, I could have found a worse batch, or one stored in unsuitable conditions. Here the results are definitely better.

The capacity is 2601 mAh / 3.24344 Wh and the operating time is 26 hours and 39 seconds. So it’s not so much better, but much better. However, the previous problem returns here: a +200% battery should be twice as good as a +50% battery. However, the improvement in results is respectively: 11.54% in the case of mAh, 14.77% in the case of Wh, and 11.54% in terms of working time. And this is the case with a battery from the better batch.

When it comes to battery prices, they can differ dramatically in different stores, even if we are talking about stationary, neighboring stores. So I’m not going to refer to them, because you can pay less for Energizer Max Plus Longest Lasting 200% batteries than I paid for Energizer Longest Lasting 50%. However, this test shows that it is not necessarily worth overpaying if the difference between them is noticeable. Especially since, as tests have shown, a potentially better battery may give worse results, and the differences alone reach up to a dozen or so percent.

One more important question remains: is Energizer lying? This cannot be said, because it is not known what the percentages declared above refer to, or what the testing procedure was like inside the company. It is possible that there are conditions under which packaging claims will prove to be true. Although I personally doubt it. I’m also not convinced that they would translate into real work. However, we can still get a response from Energizer that will dispel these doubts instead of sending us back to the contact form.