LG’s latest flagship mobile phone is designed to meet the high expectations that no-compromise, power users of Android phones have been craving. Fortunately, it manages to meet most of those demands.

The successor to one of the best phablets (phone-tablet) of last year, the G3, the G4 boasts a removable back, expandable storage and replaceable battery – the last remaining mainstream Android smartphone manufacturer to do so.

Very slightly curved

Facebook Twitter Pinterest The curve is subtle, but makes it less likely the screen will shatter when dropped on an edge, according to LG. Photograph: Samuel Gibbs/The Guardian

Like most of LG’s other smartphones, the G4’s design is rather understated. A plain black face, thin bezels, a dark chromed plastic edge and a simple plastic back.

One version offers a leather back, although that’s not everyone’s cup of tea.

LG is not going to win any design awards for the G4’s looks. It also feels a bit cheap in the hand compared with the likes of the Samsung Galaxy S6 or the iPhone 6 Plus.

A very slight curve to the screen is unusual, and is meant to help the phone survive being dropped without smashing the screen. I didn’t put it to the test but, like its banana-shaped brother, the phone feels like it can take a knock or two.

The power button and volume buttons are hidden on the back underneath the camera, which I quite like.

The screen itself is one of the best ever fitted to a smartphone, with very black blacks, true-to-life colours and a pixel density of 538 pixels per inch making it pin-sharp. For comparison, Samsung’s Galaxy S6 screen has a pixel density of 577ppi and Apple’s iPhone 6 Plus 401ppi.

Specifications

Screen: 5.5in quad HD (538ppi) “Quantum” display



5.5in quad HD (538ppi) “Quantum” display Processor: Six-core Qualcomm Snapdragon 808



Six-core Qualcomm Snapdragon 808 RAM: 3GB



3GB Storage: 32GB + microSD card slot



32GB + microSD card slot Operating system: Android 5.1 Lollipop



Android 5.1 Lollipop Camera: 16MP rear (F-stop 1.8), 8MP selfie-cam



16MP rear (F-stop 1.8), 8MP selfie-cam Connectivity: LTE, Wi-Fi ac, BT 4.1, NFC



LTE, Wi-Fi ac, BT 4.1, NFC Dimensions: 148.9 x 76.1 x 9.8mm



148.9 x 76.1 x 9.8mm Weight: 155g



Two days per charge

Facebook Twitter Pinterest Expandable storage of up to 200GB via microSD and a large, removable battery are what sets the G4 apart from the competition. Photograph: Samuel Gibbs/The Guardian

Looking at the specifications, LG has made a curious choice of processor for the G4. Typically, flagship smartphones use top-of-the-line processors, but the G4 is fitted with Qualcomm’s six-core Snapdragon 808, not the chip company’s most powerful Octacore 810.

That could be to do with reported overheating issues in the 810. Either way the G4 is snappy and responsive with no hint of lag or lack of performance.

A side-by-side real-world test of the G4 against the Samsung Galaxy S6 showed very little difference in response to loading apps, playing games and navigating through menus.

Where the G4 has the edge is in battery life. I easily got two solid days of work out of the G4 on a single charge, with push email all day, many hundreds of push notifications, some streaming music and 20 or so camera snaps.

The LG4 lacks built-in wireless charging, requiring an optional case, and charges slower than many of the competition, but then you have to charge it half as much.

Simple, fast and tap-happy

Facebook Twitter Pinterest LG’s Smart Bulletin is a Google Now-style information screen, which works well enough, but can be safely ignored in favour of the latter if everything you do is plugged into the search giant’s ecosystem. Photograph: Samuel Gibbs/The Guardian

LG customises the standard Android experience on its smartphones. Typically the system is colourful and full of options for the owner.

The changes to G4’s Android are simpler and mostly welcome. For instance, users can customise the arrangement of the standard Android home, back and multi-tasking soft keys or change the typeface and text size. A super-simple interface for “beginners” – LG’s words – is also available.

LG’s Smart Bulletin homescreen panel aims to be a Google Now replacement, pulling information from calendars, health tracking apps and the weather.

Perhaps LG’s best addition to Android is its KnockOn and KnockCode – double tap to wake or sleep the screen, or tap out a lock code on a black screen to unlock the phone. Both work well and should be standard to Android.

Camera

Facebook Twitter Pinterest The camera’s manual controls are easy to use, with simple virtual scrolling wheels featuring manual focus, while the automatic mode manages most situations well. Photograph: Samuel Gibbs/The Guardian

The G4’s camera has some of the best low-light performance I have ever tested on a smartphone. It has an F-stop of 1.8 (a measure of the speed of the lens: the lower the number, the brighter the image captured).

Most smartphones have camera lenses above two. The iPhone 6 has an F-stop of 2.2. Some, like the Galaxy S6, have F-stops of 1.9. For perspective, the prime lens on my Nikon digital SLR, which I used to take photos of the G4, has an F-stop of 1.8.

Numbers aside, the G4 makes dull days and indoor shots look like bright sunlight, with no graining or artefacts. Images are sharp and detailed, colour-accurate and vibrant, while the camera focuses fast. The shallow depth of field is also quite remarkable, creating pleasing bokeh effects.

The camera app has a manual mode, which gives users access to white balance, focus, ISO, shutter speed and RAW image files, each adjustable with an easy-to-use slider. The automatic mode does an excellent job of managing most situations, however.

The front-facing camera is also one of the best I’ve tried, once you turn off the automatic make-up effect.

Facebook Twitter Pinterest The shallow depth of field of the G4 rivals digital SLR prime lenses. Photograph: Samuel Gibbs/The Guardian

Price

The LG G4 will be available at the end of May, costing around £500 without a mobile phone contract.

Verdict

The LG G4 is a power-user’s Android smartphone. A removable battery, expandable storage and brilliant camera make up for the cheap design and materials, as every other mainstream manufacturer prefers to spend on the latter. But it doesn’t feel as premium, and isn’t made from metal, although leather options are available.

Aesthetics aside, solid performance, two-day battery life and a great 5.5in screen make the G4 one of the most usable and best phablets available.

Pros: great screen, brilliant camera, two-day battery, expandable storage, removable battery, KnockCode. Cons: lack of premium materials, plastic back easily scratched, no built-in wireless charging.

Facebook Twitter Pinterest The fit and finish of the G4 with the plastic back isn’t quite up to par with rivals from Apple or Samsung. Photograph: Samuel Gibbs/The Guardian

Other reviews

• Samsung Galaxy S6 Edge review: curves for pleasure, not function

• Samsung Galaxy S6 review: the iPhone killer

• LG G Flex 2 review: the second coming of the banana phone

• Google Nexus 6 review: big is beautiful, but not manageable

• Sony Xperia Z3 review: great battery life and quality camera