This might sound like a bit of a first world problem. But keeping more than one device juiced up with charge in your car over long journeys can be tricky. Many cars have but a single 12-volt power socket, after all.

Enter the PNY Dual USB Car Charger. It's the answer to the question, for instance, of how you keep both your after-market satnav and your phone charged on long journeys.

If that doesn't sound hugely important, it's worth remembering that the batteries in many after-market navs, like TomToms, are only designed for occasional use and rated at just a few hours. You essentially need to keep them plugged in.

What's more, different devices have different power requirements. An iPad, for instance, needs more power than an iPhone. Hold that thought, we'll come back to it.

Features and specs

Features and specs? It's a dual-socket USB adapter that plugs into a standard car 12-volt power socket, what else is there to know?

Well, not all USB charging sources are the same. The standard voltage for USB socket is 5v, but current can vary. Do the maths and the result is quite a wide range of actual power output from just a few Watts to well into double figures.

A quick glance at the front of the PNY Dual USB Car Charger reveals that you've got the bases covered. It offers both a standard one amp socket and a high power 2.1 amp socket.

PNY Dual USB Car Charger
Handy for your phone and a friend's or a phone and nav device

The latter is aimed at larger device including tablet computers. For reference the standa Apple iPhone charger is one amp and five Watts, the iPad charger is 2.1 amps and 12 Watts. So now you know.

That aside, the PNY Dual USB Car Charger's other stand out feature is a bright blue LED power indicator. On paper that's hand because with these kinds of devices it's not always obvious when they properly plugged in. With the PNY Dual USB Car Charger, that's not an issue.

Performance

From a simple charging perspective, we've no complaints. Hook up two devices including one larger mobile device and the PNY Dual USB Car Charger does what it says on the tin. It charges.

Ergonomically, however, it's not quite a total success. For starters, like many car USB adapters, it's sticks out of the socket an awfully long way.

PNY Dual USB Car Charger
Power LED can be distracting at night

That looks ungainly, which is merely a pity. But it also means that any force applied to the USB cables attached generates a bit of leverage.

That's unwelcome given that the design of car 12v sockets means adapters don't really click home with any security. That's not PNY's fault. But a shorter form factor that sits less proud of the socket would help.

As for the blue LED power ring, it's a useful feature but perhaps too bright at night. An ambient light detector is probably a bit OTT for this kind of gadget, so maybe a simple two-level switch is in order.

Verdict

In terms of doing its main advertised job, we've no quibble with the PNY Dual USB Car Charger's core functionality. It'll charge two mobile devices and thanks to 2.1 amp output, that includes more demanding tablet computers.

For under £10, that alone is probably good enough, especially when similar products like the Belkin dual charger are over twice as expensive. But if we were being really picky, a shorter body and some modulation for the power light would be nice tweaks for future iterations.