To help us provide you with free impartial advice, we may earn a commission if you buy through links on our site. Learn more

Masterlock Bluetooth Smart 4400 Padlock review

Masterlock Bluetooth Smart 4400 Padlock locked
Our Rating :
Price when reviewed : £45
inc VAT (Indoor version)

Masterlock's Bluetooth Smart 4400 Padlock is good for communal use, but it's expensive and the process is a little slow and clunky

Padlocks are great for keeping stuff safe, but they can be a nightmare if you end up losing the key or forgetting the number combination. Enter Masterlock’s new Bluetooth Smart 4400 Padlock, which unlocks with the simple press of a button when it comes into the vicinity of your smartphone.

Available in both indoor and outdoor variations, the Bluetooth Smart lock is very easy to set up. You’ll need to download Masterlock’s Vault eLocks app, which is available on both iOS and Android, and register for a free Masterlock account, but once you’ve inputted your lock’s activation code on your smartphone and tapped the button pad on the front of the lock, you’re ready to go.

Masterlock Bluetooth Smart 4400 Padlock Android app

I tested the indoor version of the Bluetooth Smart 4440 padlock. The button pad is a little spongey to the touch, but the click it emits once it unlocks provides a very satisfying bit of aural feedback to let you know the device has worked correctly. The LED ring in the centre of the d-pad will also light up green when the lock is open. You don’t even have to touch the padlock if you don’t want to, as you can set it up to unlock when you simply swipe the lock in the app list. This is still in beta for the Android eLocks app at the moment, but it did eventually work when I tried it out for myself, albeit after about a seven second wait.

You can set a manual code as a backup, which you enter using the four-way control around the central button. This is in case you don’t have your phone with you when you need to open it, and you can change this ‘primary code’ from the app whenever you please. Of course, having an and using a code is rather against the whole idea of the lock, but it’s still a handy feature.

Admittedly, I had a bit of trouble with the lock recognising my phone. It worked fine when I first set it up, but then when I came to try it again an hour later, the padlock became unresponsive and I had to close the app and enter my passcode again before I could unlock it. This is possibly because my phone and the padlock had been sitting right next to each other the entire time, but I would expect the connection to last no matter how long I left them in close proximity to each other.

Masterlock Bluetooth Smart 4400 Padlock

Another issue I noticed was it would only unlock if I pushed down on the shackle. Simply pressing the button often didn’t work when I came back into contact with the lock after leaving it in the office overnight, but it unlocked almost immediately when I held the shackle down. As a result, the Bluetooth Smart 4400 isn’t quite as straightforward as it might first appear, and it doesn’t quite inspire enough confidence in the technology to make me want to replace a traditional numeric combination lock.

One of the main advantages of choosing the Bluetooth Smart padlock, though, is the ability to share it with friends and family, making it a great choice for locking away something communal like a bike shed, or letting others into a building remotely when you’re not there. By adding guests to your padlock, you can either give them unlimited access to the lock, or limit them to 12 hour windows, such as 7am to 7pm and vice-versa.

They’ll also need to create a Masterlock Vault account and download the app, but once they’re logged in, they’ll be able to unlock your padlock using their smartphone. They can also add notes to the lock, which you can then view on your phone, and view the current primary code in case they’re having difficulties using Bluetooth.

Masterlock Bluetooth Smart 4400 Padlock Android UI settings^ The Android app is very sensibly laid out and easy to use

The app displays a history of the lock’s usage as well, so you can see who’s used it at what time, and whether it’s been tampered with. You can’t do a lot when it does send you a tamper notification, but at least it prompts you to go and check it out and see what’s wrong. That said, I managed to get a tamper notification just when I was testing it out, and I’m not entirely sure what set it off.

In the event of someone losing their phone, Masterlock recommends the owner of the lost or stolen device changing their username and passcode on its website ( Then, the owner of the lock will need to reset everyone’s padlock access, which they can do selecting Reset Keys in the advanced settings menu. You’ll need to have the lock with you in order to make any changes, though.

Masterlock Bluetooth Smart 4400 Padlock Android UI guests^ Being able to keep an eye on who’s using your lock at what times is useful, but there’s not a lot you can do when it gets tampered with

Unlike traditional padlocks, the Bluetooth Smart lock is powered by a standard CR2450 lithium battery. Masterlock estimates the battery should last around two years in touch unlock mode, but switching to the beta swipe mode will drain it much faster, as Masterlock says this will only last around 4 months of regular use. Fortunately, replacing the battery is relatively easy. The LED ring in the centre of the keypad will light up yellow when the battery is low, and all you need to do is unlock the padlock and slide out the battery tray underneath.

The problem comes, of course, when the padlock’s completely run out of power and it’s still locked, as the battery tray can’t be opened fully unless it’s unlocked. This is to prevent anyone tampering with the battery or trying to steal it, but luckily, Masterlock has designed around this, as you can still pull out the tray just enough to access the battery’s contact point. If you hold the new battery in place while your phone is in range, you’ll then be able to press the keypad or enter the primary code like normal to unlock it and replace it properly. It’s a little fiddly, but it works and it’s rather clever.

Overall, the Masterlock Bluetooth Smart 4400 padlock is a useful alternative to your traditional key or number-combo padlock if you want to keep an eye on something that multiple people need access to, and using the touch unlock system is definitely more convenient than having to scramble around in your purse or pocket trying to find a key or having to fiddle about with number locks all the time – when it works, at least.

However, when the indoor version costs £45 and the outdoor version costs £60, it’s quite expensive for something that isn’t completely seamless and hassle-free. I have no doubt as to the lock’s security capabilities, but I’d like the technology to be a bit slicker before I’d consider buying one. 

Read more