With the Asus ZenFone 3 Zoom, running out of juice will be the last thing on your mind.

The jaw-droppingly large 5,000mAh battery lasted almost 20 hours in our looping video drain tests (19 hours, 50 minutes average, to be precise). That's almost two hours longer than the premium Samsung Galaxy S8 Plus (18 hours) and more than 6 hours longer than the LG G6 (13 hours, 21 minutes). Yeah, in terms of charging cycles, it pretty much crushes every other phone out there.

We're still testing real-world usage, but let's just say it's promising at the least.

So far, that battery bliss is the best thing about the ZenFone 3, which is available online and through retailers for a very affordable $329 -- that converts to roughly £254 and AU$446. And that's a little ironic, because the phone's name conveys what's really supposed grab all the attention: the camera features. Unfortunately, the image quality we're seeing so far trails behind other phones in the ZenFone 3 Zoom's price range, including the Huawei Honor 6X and ZTE Blade V8 Pro -- but we're still testing the phone fully, so stay tuned for our final determination.

In the photo department, the ZenFone 3 Zoom has:

• Two 12-megapixel cameras (one 25mm, one 56mm with 2.3x optical zoom)
• A 13-megapixel front-facing selfie camera, with screen flash
• Portrait mode to artfully blur the background in an image (yes, like the iPhone 7 Plus does, but this one isn't as good)
• Support for 4K video
• Raw file support -- once it updates to Android 7.0 Nougat (that comes default in the new software)
• Full manual mode
• A GIF-maker built into the native camera app

Camera settings are thorough and easy to find, and the phone's light, thin, curved aluminum body never made it difficult to hold, take aim and shoot. The screen reliably flashed when I took (and then immediately deleted) a selfie.

What else does this handset have? A 5.5-inch screen and a Qualcomm Snapdragon 625 processor. You can also use it as a power bank to charge other devices. Disappointingly, our review unit is still running Android 6.0.1 Marshmallow, though Asus does promise it will upgrade.

Story updated January 4, at 2:19 p.m. PT and May 9, 2017, with hands-on impressions.