As smartphone screens grow ever larger and higher in resolution battery suffers. 4G is also an enemy of battery life and that's only getting faster. So without any battery breakthroughs coming anytime soon you're going to need a mobile charger to help your phone last the day. But which is right?

There are plenty of mobile chargers out there but do you need it for on the go, for rough situations, for multiple devices, for cheap? They're all factors that we've broken down into categories to help you find the best charger for you.

Mobile chargers are, as the name suggests, usually about being portable. If a quick burst is what you need to give you a few more hours phone use, then small is what you'll want.

Probably the smallest portable charger is Fuel. So small that it can even fit on your keychain. That means a 220mAh battery, which isn't much, but is enough to extend your phone's life by up to half an hour of talk time. All that and it's only £25 on Firebox.

What's the catch? It's micro USB only so it won't work with iPhones. That's where the Revi Charger might appeal more – it works with iPhone Lightning ports. There is also a micro USB version for other phone users. It's 2.5mm thin, like a credit card, so it's easy to carry around with you.

It has a larger 550mAh capacity and can even be plugged into USB to charge a phone while charging itself – all without extra cabling. Impressive for only $25, which is about £15. And there's a thicker 7mm version with 1440mAh battery for $30. But Revi isn't out just yet – you can pre-order now for delivery in early summer 2014.

The Cobra Electronics CPP 7500 JumPack is a portable battery that can charge a smartphone or tablet to capacity and perhaps more, as it includes a 7,500mAh Lithium-Cobalt battery in its svelte casing. It will rapidly charge a device through its 2.1 Amp USB port.

What makes it different to other devices though is that it is also capable of pushing out a 200 Amp starting current, up to a 400 Amp peak current which will jump start most cars. Jumper cables that connect to the USB port are also included.

Oh, and there's a torch on the front for good measure that can also double as an SOS emergency LED strobe light. It's on US Amazon for $130 which equates to about £100 with delivery charges to the UK.

For more juice than you could possibly want there's the Anker Astro Pro2. This 15.5mm thick charger stores a whopping 20,000mAh. That's almost 13 full charges of an iPhone 5S – at least two weeks iPhone use on the go. Plus it looks really, really sleek with that brushed metal design.

And if all that wasn't good enough it'll even charger larger devices like tablets and laptops. Not bad for €80, which is about £65.

If a cheap charger is what you want there are a few options.

The lowest end, one that might not last too many charge cycles but can be lost without too much worry, is the EPCTEK Emergency Lifeline charger which costs just £3.56. It'll hold 2600mAh which is enough to fully charge an iPhone, or most phones for that matter. You just need to plug your charger cable into the USB socket and you're good to charge.

A more reliable but also cheap option is the Duracell 3 Hour Mobile Phone and MP3 Portable USB Charger. This holds a smaller 1150mAh of battery and costs more at £12. It comes with a micro USB cable but works with iPhone cables too and at 4.5 x 9.5 x 18 cm it's not too large either.

Finally, for a little more at £15, there's a whopping 5000mAh in the EasyAcc Power Bank. This'll fully charge an iPhone almost three times and works with micro USB cables too. It's also slim enough to slip in your pocket when out and about. 

If you're carrying multiple devices already you're not going to want to carry more. So a single external battery charger for your mobile, tablet and laptop is what you need. And that's exactly what the Energizer XP18000 Power Pack is made for.

With a huge 18,000mAh capacity and multiple ports this can juice up to three devices at once, including higher amp sucking laptops. That means 42 charges of an average smartphone or an extra 6 hours on a laptop.

The price for this all-in-one powerpack? A steep £190. But you get what you pay for when it comes to batteries and Energizer is a well known brand.

Being portable doesn't mean having cables. If your device is Qi-enabled then Anker's portable charger is perfect. Featuring a 6000mAh battery the Anker Qi-Enabled Triple-Port External Battery should give plenty of full charges to all mobiles. It's on sale in Canada for $70 which is about £40.

The LithiumCard is gorgeous. Not only is it five credit cards slim for portability but it's finished in bushed metal and comes in silver or gold. It also charges at 2 amps meaning superfast juicing, or HyperCharging as it's calling it, in spite of that slim size.

The micro USB or Apple Lightning connector is built in so this unit is all you need carry.  This is Kevlar reinforced so it won't break even when 1kg of weight is pulling at it. It even has a non-adhesive, called NanoStik, that lets it connect to the back of your device.

The 1200mAh battery should be enough to fully charge an iPhone 5S for 5 hours talk time and a Samsung Galaxy S4 for 4 hours talk time. It's available to buy now for $50, which is about £30.

Bluetooth speakers can double as mobile phone chargers, giving you another reason to carry the extra battery. The Creative Sound BlasterAXX AXX 200 does just that.

For £130 you not only get a Bluetooth speaker with great sound, it will also charge your USB cable connected device. And as a cherry on top it has a mic to be used as a conference speakerphone or – get this – a megaphone. Feel free to begin throwing the £130 this costs at the screen now.

If it's an environmentally friendly option you're looking for Soulra has some great kit. It's Boost Turbine 4000 lets users crank their battery back to life. Unlike solar chargers this will work anywhere and even in the dark. And it'll charge tablets too.

One minute of crank work will be enough to add four-minutes of call time to a phone. Perfect if you're in a tight spot without battery power. It holds a 4000mAh battery which can be charged at home so the crank is just there as a safety net really. Imagine leaving the house knowing you'll never run out of battery, as long as you have time to crank.

The Soulra Boost Turbine 4000 is £70.