We’ve just finished conducting some tests on a range of different AAA alkaline battery brands to find out which are worth the price and which aren’t. With some very surprising results! Everyone buys household batteries, right? But most times we just buy what the marketing tells us to buy, without having a clue which batteries are actually the best value for money.
We felt it was time someone did a test of price, capacity and derived value for money on a range of the most popular household alkaline batteries, so we could see just what was real and what was more like marketing influenced fluff.
The battery business is a big business, very big. Every year we ritually consume upwards of 15 billion household batteries, the vast majority of which are dry cell alkaline products manufactured by companies such as Duracell, Panasonic and Energizer. Alongside the big brands are products from the OEM resellers, like supermarkets and wholesalers, as well as the ultra cheap Chinese imported zinc carbon based batteries.
In general the battery market can be broken down into four distinct areas:
* Zinc carbon based batteries. Typically sold in discount stores in packs of 10 to 20. Ultra cheap.
* Alkaline batteries, branded and unbranded. The most popular type of battery on sale because of price and performance.
* Lithium batteries, branded and unbranded. Ultra new high capacity batteries, but you’ll pay a steep price premium for them.
* Rechargeable batteries, branded and unbranded. The ‘supposed’ eco option.
There are also a couple of other areas, such as OEM rechargeable (for things like building your own battery packs) and Lithium Air watch batteries which sell mostly to specialist channels.
For our test we selected the most popular section, the alkaline battery type which makes up the vast majority of the battery sales around the world with around 80% of the household battery market. In this sector, the number one contender is without doubt Duracell, which has a 39.4% share of the market followed by Energizer/Eveready with 32%. To give you an idea of just how lucrative the battery market is, Duracell (part of the mighty Procter & Gamble group) spent $67.6 million on advertising in 2012 alone. So you can probably work out the profit potential.
For our testing rig we used off the shelf components which can be bought for very little from electronics retailers, including a USB connected multimeter from eBay, and we include the schematic at the end of the article which you can use if you want to run your own tests in your country or region. We restricted the first test to just AAA alkaline batteries because they take less time to test (compared to AA) and we felt that it would be better if we did comparison tests between different battery types in stages, rather than trying to do it all at once.
We purchased a selection of 18 generally available AAA batteries, along with a standard off the shelf USB connectable multimeter and thanks to the Ferret’s own genius engineer Maciek, we built a simple but very accurate battery power tester which we nicknamed Sparky. What makes our Sparky tester different from the battery testers you buy down Radio Shack is the fact that our model does a measured power drain at a consistent current, which ensures that we can compare each battery like for like.
Sparky’s job was to drain the battery at a consistent current of 500 mA (miliamps) until the battery reached 0.9 volts (or 3.6 volts across all four cells in the block) which is the effective end of life of the battery in real terms (aka the cutoff voltage ).
During the test, the multimeter sends a regular update every 60 seconds on the amount of voltage remaining in the cells to the computer via the USB connection, which provides a detailed log, and once the 3.6 volts point is reached, the test is finished. Actually we went a little further by stopping the test at 3.4 volts, just to make sure of the readings.
Armed with this state of the art cutting edge testing technology we set out to do a comparative test of the 18 types of AAA battery to see which batteries deserve our cash, and which don’t. The results surprised us, and we think they may surprise you too. Each test on a battery type took up to an hour or more to complete, and we used four batteries each test so as to get a consistent average from the testing results. Watch the video below to see how we did the test and the results.
The results were generally fairly close on the amount of power that each battery holds in total (measured in milli Watt hours).Â At the top end on this test there’s only around 10% separating the group, although at the bottom end the relatively cheap Philips battery was really very poor in terms of power on offer. Surprising for a major brand product. The big surprise was the fact that the best Duracell could manage was a sixth place in the chart, with the Duracell Plus. <click on thumbnails to expand>
While pure unit price is not so key to making an optimal buying decision, it’s still interesting to see which battery comes out cheapest and which brand charges a lot for their power. The mighty IKEA offers an incredibly low price product which goes some way to explaining their 2nd place position in the value chart below. The interesting thing is the two sets of batteries with similar low prices, Maplin and Daewoo, and also Tesco and Morrisons look to be similarly constructed batteries, which could indicate they come off the same production lines in China.
** Value For Money Overall **
Winners – Kodak Xtralife, IKEA Alkalisk, Daewoo Super, Panasonic ProPower, Lidl Aerocell
This is the important one. Which battery should you buy to get the best combination of low price and high power capacity? Well there’s no doubt that the top three really do offer a huge price advantage over the rest, but what is shocking is just how badly the market leading brands do in this chart. The Energizer and Duracell products don’t even feature in the top 10, which is absolutely incredible. It really does seem like we’re paying for the marketing of these brands with the higher retail prices they demand.
Here’s the spreadsheet data which gives the full battery log information. <click to expand>
As you can see from the above, there are a few conclusions that we can make.
1. Paying the most money for a battery may not give you the best value for money. As we can see the Kodak Xtralife is a far better buy than the Duracell Plus, for example, because it offers four times the power per £1 spent.
2. The trade-off with the cheaper batteries is the fact that some of them lose their power very quickly indeed, which is hopeless for higher drain devices. In fact for those devices, such as flash units for photography, it really makes sense to pay for the better battery products, especially since Lithium clearly offers a huge advantage over older alkaline technology.
Our one quick test of a Lithium battery shows the huge difference in capacity (see spreadsheet data above). But they’re *very* expensive at the moment, which means they’re probably not the best value for money for normal applications, only where you have high drain devices.
The battery business is huge and we collectively spend a lot of money on keeping our portable devices running (also ask any parent about their annual battery bill), so it definitely pays to keep up with which batteries are worth buying. We hope this test and review has helped, and if you’re interested in having your own set of batteries tested by Mac and Sparky, send us an email to mac at redferret.net and we’ll give you details of where you can send your batteries to be tested for free.
As promised earlier, here is the schematic of the current regulator board at the heart of the tests, so you can have a go at building your own test system.
1. This is strictly a COMPARISON test. The idea is not to highlight good and bad batteries, but to compare them with each other to identify value for money. Please don’t attack us because your favorite battery doesn’t perform as well as you believe it should.
2. By using an LM317 current controller, the current is stabilized to ensure all batteries are tested on a flat playing field irrespective of their initial internal resistance state.
3. We did not factor in battery age because all batteries here are required to meet EU regulations for Best Buy Date. Note that batteries such as the Energizer Ultra+ now include PowerSeal which gives a 10 years locked in shelf life guarantee. That doesn’t guarantee better value, but it’s something to consider if you’re buying batteries for long term emergency storage.
4. We will be testing Lithium batteries shortly, but we couldn’t resist doing one quick test with an Energizer Lithium Ultimate and the results were startling. The battery started at 6 volts and held 5 volts for 77 minutes compared to the longest alkaline (Panasonic Evolta) which held 5 volts for just 10 mins. Once the price comes down to a sensible level these should be the first choice battery for modern high drain devices.
5. Prices are heavily dependent on the retailer. We bought a good number of our test batteries (including the Duracell Simply) from Pound Shops (equivalent to Dollar Stores) and supermarkets. Amazon surprisingly has a mixed track record, with some brands cheaper and some more expensive than you can find elsewhere. It pays to search around!
6. We also tested six ultra low priced Chinese Zinc Carbon batteries but the performance was generally so dismal that we will have to re-test with different settings to get a meaningful result. The batteries we have looked at so far are Panasonic, Sony, Kodak, JCB and Hyundai. In each case our 500 mA (miliamp) battery drain killed the cells in around 2 to 10 minutes (vs 50 – 76 mins for alkaline). Zinc Carbon are clearly really only suitable for *very* low drain devices (such as small LED flashlights).
7. The best value for money battery – the Kodak Xtralife – was bought in a 6 pack for £1 at a Pound Shop. Smart battery buying favors the alert opportunist shopper.
8. It is possible that some of the poorer results are the result of failed batteries during the test, but since this reflects a problem with product reliability we felt it still provided a valid data point for the value of the battery in general. In other words, if 25% of your battery 4 pack fails early during use, it’s not that great a value for money, is it?
9. The biggest shock of the tests was the fact that the market leader Duracell is four times worse value for money than the winning Kodak battery. And we have no explanation for why the Duracell Ultra Power comes dead last in our Value for Money chart.
Well actually we do know why the Duracell brand seems to be poor value. It’s not the capacity, they’re just too expensive compared to some other brands. Someone has got to pay for that $67 million advertising budget we guess, and it seems to be us.
1. Even when your alkaline batteries have reached their cutoff voltage and won’t work with your high drain device, you can quite easily cascade them down to lower drain devices and they should work, because the battery can refresh the chemical reaction even after being drained.
For example, we took the Duracell Ultra Power batteries after our drain test and put them into a cheap LED light and they worked fine for 24 hours non-stop (in fact the light was still going when we stopped the test, see above photo).
2. You can easily mix and match different alkaline batteries with no problem. If one of the batteries is part used, however, the device will stop working quicker as you might expect, when the part used battery runs out of charge. In which case just drop in another part used battery and carry on. Rinse and repeat until both batteries are drained.
How long the device runs will of course depend on the remaining capacity and the drain of the device.
3. Battery leakage is usually caused by a manufacturing defect of some sort. This is typically in the sealant which surrounds the positive terminal. See image. Note the breather hole as well.