The EU has published a database of smartphone battery lifeIt suggests Samsung’s Galaxy S25 Ultra offers excellent battery longevityThere are plenty of other interesting revelations found in the dataIf you’re looking for the phone with the best battery life overs its lifetime, the European Union (EU) has just made your job a little easier. That’s because it has published a database of battery ratings (via Android Authority) for a huge number of the best smartphones, and there are some fascinating revelations buried within.Searching through the EU’s new European Product Registry for Energy Labelling database isn’t particularly straightforward – you need a phone’s model identifier number rather than just typing in something like “Google Pixel 9a” – but once you’ve got that, you can get info on battery life, ingress protection, drop resistance, and more.That makes it a useful way to put phones up against each other and see which has an advantage. For instance, in the eternal battle between Samsung and Apple, we’ve compared the battery ratings of the flagship iPhone 16 Pro Max and the Samsung Galaxy S25 Ultra. Here, something interesting emerges: the S25 Ultra is rated for twice as many battery charge cycles as the iPhone.Specifically, the EU reckons the Samsung Galaxy S25 Ultra is rated for 2,000 charge cycles, whereas the iPhone 16 Pro Max sits at 1,000 cycles. That would appear to give Samsung a significant win in the battery department, on paper.However, it’s not quite as clear cut as that. The S25 Ultra’s “battery endurance per cycle” rating sits at a hair under 45 hours, which the EU says means “how long a smartphone's battery lasts from a full charge to when it needs to be recharged again.”For the iPhone 16 Pro Max, its battery endurance per cycle is higher at 48 hours. So, the iPhone might last a little longer per charge, but the S25 Ultra is rated for more charge cycles in total.Comparing the best smartphones(Image credit: Shutterstock)What about the charge cycles of other popular phones? We’ve found the database entries for the top devices in our list of the best smartphones and entered them into the chart above for easy comparison.Looking at the data, it’s clear that the OnePlus 13 offers by far the longest charge per cycle at 61 hours and 36 minutes. The iPhone 16 Pro, meanwhile, is bottom of the pack at 37 hours. But both phones are rated for 1,000 charge cycles.The total number of charge cycles isn't an estimate of how many a phone's battery can take before it dies, but rather the number of complete charges until you start to see degradation in its performance. So the figures above aren't necessarily an estimate of a phone's overall life cycle.How do we know how reliable all of this is? The information is almost certainly self-reported, which – you would think – could lead to dodgy scenarios and an incentive to fudge the numbers. There might be some reliability, though, as the EU has set out regulations on how battery endurance should be measured. Providing those are being adhered to, we can put a little trust in the numbers, although we can’t be 100% certain.Besides needing to take these figures with a healthy degree of skepticism, there’s also much more that goes into deciding which phone to buy than just looking at its battery capabilities. You need to consider its chip, cameras, software, durability, and much more. But if you prize battery life over a phone's lifetime above all else, the EU’s database could be a helpful resource indeed.You might also likeThe best phone 2025: we've tested and ranked the top phones you can buy in the USSamsung Galaxy S25 Ultra review: the ultimate AndroidApple iPhone 16 Pro Max review: a beautiful, intelligent beast