Amazon Prime day hits on 13 October. If you have your eye on some exciting new gadgets, don't forget the batteries to power them. The best we've tested could keep your new digital cameras or wireless speakers going nearly twice as long as the worst.
In our latest tests we've pitted cheap batteries from Ikea (23p per battery) and the Amazon Basics range (55p per battery), against more expensive batteries such as the Panasonics Evolta Neo, which cost nearly £2 per battery*.
You'd assume that paying more for batteries would guarantee you better performance, but our tests have found this isn't always the case. We've identified Best Buy batteries that cost less than half as much per battery as pricier alternatives that fail to make the Best Buy grade.
We put every battery through a 'battery' of tests that simulate how you use them in different conditions.
We found that one of our newly crowned Best Buy AA batteries has enough energy to power your digital camera for around nine hours before it runs out, your digital radio for 27 hours, or over 100 hours in a lighter drain device, such as a remote control or your kitchen scales. The worst AA batteries we've tested would give up nearly four hours sooner in high drain conditions.
We don't expect quite as long a life from smaller, AAA batteries, but one AAA battery performed so badly, it's become a Don't Buy. It lasted just over three hours in high conditions before running out. The best we've tested last nearly five hours before you'd notice a dip in power, and longer before they run out completely.
Our chart below shows the difference in performance between the best and worst batteries in high, medium and low drain conditions. The chart shows the time in hours (down the left hand side of the chart) that you'll get from a single battery before it runs down to 1v. This is when you'll notice a dip in power and your devices may stop working properly.
Over the years our tests have shown that there can be big differences between how long batteries from different brands will last in various devices, so you need to choose with care.
The best batteries for the job will depend on what you want to use them for.Check our to find batteries that are long-lasting, but within your budget.
* Based on prices given at Amazon £23.66 for a pack of 12 for the Panasonic and prices given at Ikea £2.25 for a pack of 10.