Ah, the old battery life test. One of the world's most difficult things to rate, thanks to the sheer range of things you can do with the phone to keep it from throwing out all its juice in a heartbeat.
If you can't be bothered to read why, just understand that Galaxy S4 = pretty good battery life.
For one person the Galaxy S4 is a treasured beast, only brought out into the dappled light to check emails manually once an hour for most of the day. For the next it's an all-powerful media gruntmonkey, one that will be streaming movies over a 4G connection while auto-updating every app under the sun.
Whatever you use your phone for, in our eyes it should be able to handle what the handset's main USPs are.
But the good news is that the Samsung Galaxy S4 is able to handle all the things you can throw at it and still keep the 2600mAh battery chugging along at the end of the day. We found that in general use it was very well received, as nothing we found could hurt it.
Our usual test is performed on the commute to work, the time where we're at our most 'phone-use-y'. For this test, like all other phones, we streamed the audio over Bluetooth headphones (Rockaway Novero, if you're asking).
A 10 minute cycle ride with music playing dropped things by 1%. Streaming video over 4G for 10 minutes with full brightness on the screen pulled down another 3%. Then it was more music for 30 minutes, which ate another 2%, and then downloading a 86MB game file over 4G, which munched 3%.
A little more music playing, combined with general email checking and testing out the air gestures, air view and smart scroll saw a battery drain of just over 10% for the hour we were trundling to work. That's really impressive, as we reckon high drain capability of 10% per hour will lead to more than enough juice come the end of the day.
We never found ourselves in that situation, which is great. You can always pop in another battery, thanks to this being removable, but in truth, it wasn't needed.
We will say that those that like gaming, movie watching and internet browsing will struggle to make the battery last on this phone, as the screen is the biggest drain. That sounds obvious, but we're actually happy that the Galaxy S4 isn't one of those devices that will see your battery juicing down from an overly-enthusiastic background syncing process.
After a few months of using the Samsung Galaxy S4, we found that the battery life was definitely better than other models on the market. With medium to low usage, you'll easily get to 50% by the end of the working day, and that's including some music streaming, internet browsing and video watching.
The Galaxy S4 has an excellent sleep mode that means that when it's inactive it can really drop the drain on the CPU, and achieve that in a much better manner than other devices.
While the S4 is OK, the lower-end CPU isn't up to the power of the Qualcomm 800 seen in the LG G2 and Sony Xperia Z1 Compact - these are much more power efficient and are even more adept at connecting to wearables without an impact on battery life.
Connectivity on the Samsung Galaxy S4 is well catered for, thanks to simply packing every kind of sensor under the sun in there. For instance, you've got low power Bluetooth (Bluetooth 4.0) which means you can connect to a wide range of sensors - like trainers - and have them send back up data without taking up loads of power and sucking the battery dry.
As you can imagine, S Beam and NFC are both present and correct on the Samsung Galaxy S4, with both working well in tandem to nab stuff off other phones which you've tapped the back of.
It uses a Wi-Fi Direct connection to make it easier to send items from A to B, and does do very speedily indeed. It might look odd, but we still believe massively in the power of NFC thanks to the plethora of speaker docks and headphones that now use it for easier Bluetooth pairing.
GPS and GLONASS are on board, as we mentioned above in the Maps section of the review, and combined offer a startlingly quick location time when firing up the mapping services. Seriously quick – we urge you to try it.
The Samsung Galaxy S4 supports all manner of Wi-Fi connections, and can hang on to the signal even when weak thanks to dual-channel bonding to preserve the data transfer.
We can't say that we noticed much of an upgrade over other models, but then again that's not bad thing as most of the top end smartphones will now manage to offer decent Wi-Fi connections given they're so crucial to the running of the phone.
When downloading large files we did notice some dropouts and speed losses, but that was more to do with the server connection it seemed. A 700MB video file from Samsung's Video Hub took a lot less time to download than a 590MB file from Need for Speed: Hot Pursuit.
We were testing the Samsung Galaxy S4 on the EE network, and if you're new to the 4G game then we urge you to make sure you're going to get the superfast service on your new S4, should you have got this far and decided to rush out and buy it.
From app downloads to streaming video, it was just so fast. Web pages load in a heartbeat, updates occur almost instantly and everything you could hope for is serviced by upping the speeds to 4G levels.
If you've got fibre optic broadband then the effect is similar – we're loving the fact you can download things on the go at lightning speeds. The S4 is well set up too – we moved between two tube stops (overground, obviously) and managed to nab a massive 87MB of data in just a few minutes.
The data levels need to be watched though. It's very easy to get over excited with 4G on the Galaxy S4 as so much of it is enhanced by the faster speeds – from video to music to game downloads, we found ourselves wanting to do everything superfast, and as such were heading between 500MB and 1GB of data per day.
So make sure you've got enough data to manage – if you want the full force of 4G, you'll probably be wanting at least 8GB of data, if not more.
One more thing...
Oh, and a big shout out for USB on the go. It's a massively underloved feature that enables you to connect a USB dongle to your Galaxy S4 and transfer files without having to fanny about with microSD card and taking off the back of the phone.
Yes, you need a separate cable, and yes, finding one is harder than extracting teeth from a chicken, but we still like to see it added as a feature.