Paul checks out misleading smartphone specifications, a hefty battery pack, and some wireless and not-so-wireless cameras.
Paul Ockenden checks out misleading phone specs, a hefty battery pack, and some wireless and not-so-wireless cameras
There’s a common misconception when it comes to the batteries inside smartphones, tablets and other gadgets. When you read the marketing blurb, or scan through the reviews of the latest phone, you might discover that it has a 3,000mAh battery powering it. Quite why they can’t say 3Ah is beyond me – perhaps they think people will be suckered in by the bigger-looking number.
So for a completely exhausted phone it will take 3,000mAh to completely recharge it, right? Wrong. And even if we discount the fact that a phone battery won’t ever be completely flat, and the inefficiencies involved in the charging process, it’s still wrong.
You see, the battery in your phone may well be rated at 3,000mAh, but being based on some kind of lithium chemistry (you can no longer just say lithium ion – there are many variants), the average voltage of the battery will be around 3.7V. A little more when fully charged and a little less when just about to die; but 3.7V is a good ballpark. The real power capacity of your phone battery is 3.7 x 3 = 11.1Wh (Watt hours).
So quoting mAh is pretty silly. Why? Well forget phone batteries for a moment. Just think of a typical AA alkaline battery. One battery will have a voltage of 1.5V, and a rated capacity of 2,500mAh. But what happens if we introduce three more batteries? Put them in series and the voltage increases to 6V, but the capacity remains 2,500mAh. Put the units in parallel and the voltage remains at 1.5V, but the capacity quadruples to 10,000mAh. This is the reason that the industry quoting mAh values for battery capacity is bonkers. In those two series and parallel configurations, the power capacity in Wh – or even mWh, if you prefer – remains the same: volts x amps = watts.
So, the phone with the 11.1Wh battery inside, charged using a bog-standard 5V charger, will be fully charged after 2,220mAh. Not the 3,000mAh stated in the reviews. And if the phone negotiates a 9V feed from the charger then it will be full after 1,233mAh. It appears that the battery is smaller, but it isn’t.
For this reason, I’d much rather see Wh used for capacity. And I’d refer to the Ah or mAh figure as “capability” instead. However, I doubt things will change in the near future. Although, strangely, laptops generally refer to watt-hours in their specs for battery capacity.
Things are confusing when dealing with phones and tablets then. But it becomes even more so with external power-bank devices, which are becoming ever more popular. Again, they’ll feature a mAh rating – usually in the product name.
I’ve tested dozens of the devices and, very often, the quoted capacity is a pure work of fiction. Some of the cheaper kit provides less than half the stated capacity, even if we assume it’s based on the internal 3.7V battery voltage rather than the 5V output. But, of course, because mAh is actually quite a meaningless measure of capacity, manufacturers can get away with it. They could simply say that would be the capacity at 1.2V.
Some of the bigger brands do quote more realistic capacity figures. Anker
seems pretty good, especially with its more recent devices. But my favourite power bank at the moment is the Mrcool USB Type C Power Bank 24,000mAh. At the time of writing, it costs £36 on Amazon ( pcpro.link/283power).
It’s a beast of a power bank – not too huge, but solid and heavy: just under half a kilo, according to my kitchen scales. That’s a good sign: kit that doesn’t live up to the advertised capacity often feels lightweight.
A unit of 24,000mAh at 3.7V gives a power capacity of 88.8Wh – and in my tests, this was almost spot on. But what sets the Mrcool power bank apart from competing devices isn’t its capacity or weight. It’s the input and output options. There are three outputs available, two are USB and they both provide full Qualcomm Quick Charge 3 support.
I’ve verified that both work totally independently, too – I’ve seen one of these outputs delivering 5V at 3A, while the other transfers 9V at 2A. They also support 12V at 1.5A, should your phone or tablet request that. Incidentally, that 88.8Wh rating is just under the 100Wh that most airlines use when determining whether batteries can be carried into the cabin, which is great news for frequent flyers.
If you find all of these numbers confusing, the important thing to note is that it will charge a modern phone super-quickly. As fast as the supplied wall charger, or even faster with some phones!
There’s a third output on the Mrcool power bank in the form of a USB-C socket. From my tests I think it supports a subset of the PD (Power Delivery) standard. The USB-C port is also used for charging the unit – it takes around eight hours to charge to full from empty. This may sound like a long time, but it’s actually remarkable given the huge capacity on offer here.
To put that capacity into context, I’m currently using a Samsung Galaxy S8 as my daily workhorse phone, and by the time I go to bed, the battery is normally showing somewhere around 25% remaining. I fully charged the Mrcool and then used that as the exclusive power source for my phone, to see how long it would last. It made it to around a week and a half.
That’s astonishing, and makes the device ideal for holidays or business trips. Or it might prove useful in instances where there isn’t a convenient power point to plug in a conventional charger. It could also be used to power devices that use USB-type power supplies, such as cameras – more on that later.
Most other power banks will have a few LEDs to show the charge state, with some displaying a single warning light when the charge runs low. The Mrcool has an LCD panel that not only shows the exact percentage of charge remaining, but it also displays the input and output voltage and current, and lets you know whether Quick Charge is being used. It really is a fantastic bit of kit.
Camera obscurer
Some people hate the idea of security cameras in their home and/or business, feeling it’s an invasion of privacy. Others aren’t bothered by them at all. I have a friend whose house has units in almost every room – it doesn’t bother him or his family.
A sensible balance is to have cameras covering the external parts of your property, and at entrance points, leaving the main living and/or working areas as a more private space. An alternative is to use internal cameras to protects areas where you might have valuables, using timers or interfaces to your alarm system so that the internal cameras are enabled only when there shouldn’t be anyone in the building.
There are two schools of thought when it comes to the visibility of security cameras. One is to make them so obvious that they act as a deterrent. The other is to hide them, so you’re more likely to catch miscreants unawares.
I’m in the latter camp, which is the reason most of the cameras I’ve written about in this column have been small, battery-powered devices. My favourites remain the Blink system (now owned by Amazon), and Netgear’s Arlo – and both ranges have seen updates recently.
Blink’s new camera is the XT. I say “new”, but it’s been available in the US for some time; it’s only recently appeared on this side of the pond. It’s a similar size to the existing Blink camera, but it’s black. Rather than the bright-white light sported by the original camera for night-time illumination, the XT uses infrared so it’s stealthier. However, the biggest difference is that the XT is waterproof, and so can be used outdoors. It also offers 1080p video, where the original Blink supported only 720p.
It communicates using your existing Wi-Fi network. But, as with the original Blink cameras, it needs a Sync Module sitting somewhere within range to control the operation. And bear in mind the Sync Module isn’t weatherproof. One good thing with the Blink XT is that it has a switch inside that disables the status LED. This again adds to the stealthiness of the unit, since there’s no visible indication of the device recording.
The Blink XT runs on normal AA lithium batteries, with the manufacturer claiming a battery life of up to two years. In my tests, I’ve found that this is reduced if the camera is triggered frequently (which stands to reason), but also if the Wi-Fi signal strength is poor. The great thing about Blink is that there are no subscription fees for ongoing storage. The downside is that, unlike the Arlo, there’s no web interface – only
“Fully charged, I used the Mrcool as the exclusive power source for my phone. It lasted a week and a half”
“There are a few proper wireless cameras on the market now, but the majority require a Wi-Fi connection”
Android and iOS apps. And there appears to be a problem with the former, inasmuch as notifications can be missed if the phone has gone into one of Android’s deeper sleep modes.
Overall, though, Blink is good. It’s cost-effective compared to rivals and the new XT camera is a great addition to the lineup.
Moving on to Netgear’s Arlo system, from which I’ve been testing two new cameras. The first is the Arlo Go, which is effectively an Arlo Pro camera with a built-in 4G modem. In fact, you can only use this cellular connection; you can’t hook up an Arlo Go to an existing base-station. But that’s fine; since it doesn’t connect to an existing system, you have the flexibility to set up different scheduling and geofencing rules.
The camera I have here is branded as V-Camera by Vodafone, and it’s part of the company’s new range of connected kit. I’ll cover some of the other devices in the next few months.
The V-Camera is supplied with a micro-SIM that costs just £4 per month when used in the Arlo Go, but it’s available only to existing Vodafone customers (the £4 charge is added to your normal monthly bill). On the plus side, the SIM has the usual free European roaming that you expect from a phone SIM these days, so you can take the Arlo Go on holiday and use it to protect your hotel room or holiday cottage.
It’s slightly bigger and heavier than an Arlo Pro, and it works with the usual screw-in camera mounts –but not the round-ball magnetic mounts to which other Arlo cameras will attach. I don’t think that’s a bad thing because the Go is more likely to be used in remote places, so better security is a good thing.
I love the fact that you can leave this camera hidden in the middle of the forest, miles away from any mains power connection or Wi-Fi signals, and it will record any activity it spots and upload the clips to the cloud. The battery is sufficient for around a month, but you can extend that using a solar panel, which is available as an optional extra.
I can think of myriad uses for the Arlo Go. My unit is currently keeping an eye on the house of a relative who died recently. But for a few days before that I was using the device as a wildlife camera to record birds and foxes in my garden. There are several proper wireless cameras on the market now, but the majority require a Wi-Fi connection to talk to their various cloud services. The Arlo Go is one of a few that don’t even need Wi-Fi – and I love it!
The other new Arlo camera that I’ve been testing is the Pro 2. As you can probably tell from the imaginative product name, it’s an update of the Arlo Pro. It’s moving in a different direction to the Arlo Go, however – I’ll come on to the reasoning in a moment.
The headline change is that the video resolution is now 1080p rather than the 720p of the previous Arlo lineup. As with the Blink XT update, this effectively doubles the pixel count and, as a result, the footage is noticeably clearer. Faces are easier to recognise – and, for externally mounted cameras, you’re more likely to be able to read the number plate of a vehicle that pulls onto your property. It’s worth the upgrade for this feature alone. But there are three more tricks that the Arlo Pro 2 pulls off, albeit with a great big caveat.
The first is that it pre-buffers footage, so can upload clips that begin three seconds before any motion is detected. This overcomes one of the main complaints users had about earlier Arlo wireless cameras. The second is that you can define motion-detection zones, allowing you to monitor specific areas – or mask out parts of the image where you’re not interested in triggers. It isn’t quite as flexible as some other systems, since these detection zones can only be rectangles. The final change is that, on payment of an additional subscription fee, you can have continuous video recording to the cloud, such as that offered by Nest. This moves Arlo into a different league entirely.
I mentioned a caveat, and also that the Pro 2 is moving away from the philosophy of the Arlo Go. The problem is that these three features all rely on the Arlo Pro 2 having a continuous power feed. Netgear also says that they only work indoors – but my tests suggest otherwise.
The reason a power supply is needed is because these features are quite hungry. My measurements show that when powered, the camera consumes around 1.62W and becomes quite warm. If you unplug the power lead, the camera continues to work like a higher-resolution version of the Arlo Pro, but it drops back to a lower-power mode and the three additional features stop working. Incidentally, when powered the motion detection uses the image sensor (hence the ability to define zones), but when running on the internal battery it reverts to PIR detection.
However… Remember that Mrcool power bank I wrote about at the start of the column, and the fact that it provides 88.8Wh of power? Well, at 1.62W the power bank will last almost 55 hours, or just over two days. I’ve tested this and the Arlo Pro 2 runs very happily indeed when plugged into the Mrcool – and all of the additional features work just fine.