6 Devotec Fuel Micro Charger
It's only good for a tiny charge; this novelty charger for Android phones and Kindles is all about the look. Weighing just 19g and measuring 38x27x13.5 mm, this red or green device is shaped like a jerry-can and features a micro USB tip that needs to be 'poured' into a smartphone.
At a mere 220 mAh the battery is only going to send 10% – tops – into a smartphone, but that could be enough to get you out of a jam (or give you an extra couple of days' reading on an E-Ink Kindle). The upside is that it only takes a few minutes to fully recharge itself from any USB slot.
Including a lanyard for attaching to a keyring, the Devotec Fuel Micro Charger is by far the easiest battery here to travel with – it's so tiny – but there are better value approaches to portable power. A version with an Apple Lightning adaptor will follow later this year.
7 Patriot PCPB90002 FUEL+
If you're constantly on your smartphone and are heavily using a tablet every day, too, it's probably time to … get some exercise, but start by hunting down the Patriot PCPB90002 FUEL+.
Though the brand makes all kinds of different shaped and specc'ed portable batteries, this flagship product houses a giant 9,000 mAh battery.
With a couple of USB outputs for simultaneously charging a smartphone (through its 5V-capable slot) and a tablet (via the 2.1-amp slot), the Patriot PCPB90002 FUEL+ is a little weighty at 190g and 114x93x25mm.
However, since it's capable of charging-up a smartphone three or four times (it can fill-up an iPad Mini 2 from scratch), the Patriot PCPB90002 FUEL+ is the one to hit on for long haul flights.
It's also one of very few portable batteries that isn't black; the Patriot PCPB90002 FUEL+ comes only in white with a red flash.
8 Energizer XP4006 Portable Power Tab Charger
£39.99 ($66 /AU$71)
For a battery to be portable, it needs to be lightweight and slim, but it's normally a trade-off with capacity. Not so on the Energizer XP4006, which weighs just 110g despite offering a 4,000 mAh battery.
As adept with a tablet as a smartphone, dual USB outputs make it handy when travelling with two touchscreens; the Energizer XP4006 can re-charge an iPhone 5S from scratch and lends an iPad Mini 2 a 40% blast.
Best of all, the Energizer XP4006 is shaped like a big-screen smartphone, and at 21mm slim it's primed for a jacket pocket.
9 Proporta TurboCharger 7000
This 7,000 mAh battery is all about value. Pound for pound one of the most attractively priced portable batteries of all, the Proporta TurboCharger 7000 has a smooth silicon shell – most are shiny and fingerprint-hungry – and a charging button on its top side.
It weighs just 180g and measures 119x73x12mm, but it's easy to travel with in other ways, too; Sony Ericsson, Nokia, Apple 30-pin and mini USB adaptors are supplied in a small travel pouch, though any device using USB is compatible.
Better still, the Proporta TurboCharger 7000 ships with two retractable USB cables – one for charging-up the battery, and one for connecting to those adaptors – thereby promising tangle-free trips with your gadgets.
10 Monster PowerCard
How about filling a credit card slot in your wallet with portable power? At just 19mm slim, Monster's effort is rather too chunky for most wallets, but this is still the ultimate in convenience.
Better thought of as pocket-sized (it's ideal for a shirt pocket), the PowerCard has a 1,650mAh battery so is good for around a 50% charge of an iPhone 5S/5C.
Though it doesn't play nicely with tablets, the PowerCard claims to supply a quicker than usual charge by dint of its 1.5-amp USB output. In our tests it wasn't faster, taking about 50 minutes to completely discharge.
Unfortunately the PowerCard makes a bit of a fuss as it recharges flashing blue LEDs on and off, so it's best not used overnight in a bedroom.
Still, the PowerCard in silver, black or red is a good valuer on-the-go portable battery to get you through the commute home.