With the massive amount of email checking, texting, mobile gaming and internet surfing everyone does, a reliable, portable charger has become essential to avoid that inevitable dead battery.

Whether you're traveling for business or pleasure, going camping or simply out of the house all day, you'll probably need something that isn't too cumbersome and has enough juice to power your mobile devices.

Based on amount of usage we were able to get, weight, size and overall functionality, we tested a variety of chargers by mixing around charge times with an iPhone 5, Samsung Galaxy S4 and iPad 4 in different situations to create a list of the best portable chargers - though most of the external batteries are compatible with an assortment of phones, tablets, cameras and handheld gaming devices.

Generally, the portable chargers are on the pricey side but you'll definitely get your money's worth for large mAh capacities and moderate to heavy form factor, or decent capacities and lightweight portables.

We've also added a few chargers that even smaller making them more suitable for a day out rather than a long trip away, just in case you're just looking for a quick backup charge.

The 4G war is heating up in the UK and Vodafone has mobilised its troops in an attempt to win more custom, offering an extra 4GB of data every month to pre-existing and new 4G customers.

Its "4GBonus" promotion (see what they did there? Clever) will give anyone currently on a Vodafone 4G plan an additional 4GB on top of the allowance already provided in their contract.

If we look at the SIM-only plans that means you'll now get 6GB for £26 per month, 8GB of data at £31 per month and a whopping 12GB if you are prepared to splash out £36 for 12 months - trumping EE and O2 at every price point.

Get in there soon

For those of you not currently a 4G Vodafone customer you'll need to sign up to a 12 or 24 month plan before the end of the October to take advantage of the offer.

Currently Vodafone's 4G rollout has only hit London making the service pretty limited and the smallest out of the trio of networks, but from September 28 it will arrive in Birmingham, Coventry, Leicester, Nottingham and Sheffield.

We can't help but think the timing of this announcement is a little coincidental, considering a certain Cupertino-based firm is said to be launching a couple of new handsets (the iPhone 5S and iPhone 5C if you've been living under a rock for the past months) tomorrow.

O2 and Vodafone are currently in the tricky position which sees their 4G networks unable to support the iPhone 5, so the hope is the new iPhones will be more forgiving when it comes to frequency.

• Unsure on your mobile usage? Find out how much 4G data you really need

Now that everybody's rolling out 4G mobile data, it's time to compare data plans - and in particular, how much data you can use each month.

While Three promises all-you-can-eat data when it launches in December, the other operators will cap your downloads according to your data plan, even on the most expensive tariffs.

So which one's best, and how much data do you really need? Let's find out.

Who offers what?

To keep things simple we'll compare each provider's SIM-only 4G plans; if you need a 4G handset too you should of course expect to pay a little bit more.

EE's cheapest plan is £21 per month for 500MB, rising to £36 for 5GB and £61 for 20GB if you sign up before the end of October.

Vodafone's cheapest is £26, but you get 2GB. The most expensive plan is £36 per month and gives you 8GB.

O2's cheapest tariff is also £26, but the data allowance is 1GB. £31 gets you 5GB and £36 gets you 8GB if you sign up before the 31st of October.

Three says its tariffs will be the same as 3G, so that should be around £12.90 for unlimited data.

How much data do you need?

This is a bit of a "how long is a piece of string?" question, because the amount of data you use will of course depend on what you do. If all you use your handset (or tethered tablet or computer) for is checking email and browsing the web, you won't go through much data - but once you start streaming and downloading the numbers soon add up.

It's important to think about what data you might use rather than just look at the amount of data you use now: for example, you might barely bother with YouTube clips or HQ streaming on your current 3G phone because your connections isn't good enough.

Given a faster, more reliable connection, which is what 4G is all about, then your usage may change dramatically.

Here are some numbers to think about:

Music streaming (average quality, 160Kbps): 1.2MB per minute, 72MB per hour
Music streaming/downloading (320Kbps): 2.4MB per minute, 144MB per hour
iPlayer video: 50MB to 225MB per hour
Netflix video, SD: up to 0.7GB per hour
Netflix video, HD: 1GB to 2.8GB per hour
Photo uploading: 5MB per photo
Online gaming: 5MB per hour

[sources: Spotify, BBC, Netflix, Verizon Wireless]

What does that mean in practical terms?

Let's take a real-world example: you stream an episode of your favourite sitcom on the train (50MB), check Twitter whenever you're waiting for the lift (2MB), upload a photo of your lunch (5MB) and stream a few songs as you jog around the park for twenty minutes (24MB at average quality).

That's 81MB in one day. Keep it up every weekday and you'll go through 1,620MB (1.6GB) in a four-week month - and that doesn't include any incoming emails or smartphone app updates.

Maybe you're not so keen on streaming but you're a social media addict. You average five photo uploads per day (5MB each) and spend around fifteen minutes a day clicking on people's Facebook updates and photos (5MB in total). That's 30MB per day, which works out at 840MB if you do it every day in a four week month.

Perhaps you just want to use your 4G phone to tether your laptop, browsing around 30 web pages per day. The average web page is now 1MB, so that's 30MB per day or 900MB per month.

According to Vodafone's figures, which use slightly different numbers to ours, if you don't stream anything but make 12 social media posts, send or receive 12 emails and use 12 websites or apps every day, you'll use 510MB per month. Add 12 minutes of streaming music and 12 of streaming video and you're looking at 2.09GB.

Fancy busting through the 8GB barrier? To do that, Vodafone reckons you'd need to stream 36 minutes of video, 120 minutes of music, make 48 social media posts, send and receive 56 emails and look at websites or apps 30 times per day.

You can minimise those numbers, of course: you might download your music for offline listening, or use Wi-Fi wherever you can (EE, O2 and Vodafone all offer Wi-Fi minutes as well as mobile data). But the numbers give you a good indication of just how much data you might need for everyday activities. As you can see, you don't need to be downloading enormous amounts of data to exceed the cheaper plans' limits.

Are the networks having a laugh?

Left to their own devices, companies will try to offer as little as possible for as much as possible - but once things get competitive, they're usually forced to raise their game or fall by the wayside.

There's already evidence of that happening: with rivals' 4G launches imminent, EE decided last month to double the data allowances on its £26 per month tariff and up its £51 per month plan from 5GB to 20GB for anybody signing up before the end of October.

As the various networks roll out beyond the initial handful of locations we'd expect competition to become more fierce - and we can't wait to see what happens if Three keeps its promises and offers 4G connections for 3G money come December.

One thing's for sure: the prices and plans available today will look fairly stingy years or maybe even months down the line.

Is it time to sign up? Let's ask consumer magazine Which? its advice: Consumers should "not upgrade" because coverage "is too limited" to make the cost worthwhile. Phone users should wait until "coverage improves outside big cities."

4G? Nope. 3G, in 2004.

• What's the best 4G network? We pitted EE against O2, Vodafone and Three to find out

We're into the final 36 hours before Apple's iPhone 5S event so get ready for the leaks to get granular.

And you don't get much more granular than "THE SQUARE ON THE HOME BUTTON IS GONE" and "OMG IT'S EXACTLY THE SAME WEIGHT AS THE iPHONE 5" on this leaked spec sheet for the upcoming smartphone.

The fact that so many details are literally exactly the same as the iPhone 5's does make us question the legitimacy of this spec listing which comes from a Chinese network via CTechCN.

Camera bag

For the same exact size and weight, the sheet claims that the iPhone 5S will come packing an Apple A7 processor (versus the iPhone 5's A6) and a slightly improved camera with f2.0 aperture, double-flash and 1080p video recording.

It's worth bearing in mind that these specs could relate to an iPhone 5S specially formulated for the Chinese market.

It's also worth bearing in mind that they could be completely made up.

Still, not long till we find out for sure: join us here or on Twitter on Tuesday September 10 at 10am PT / 6pm BST / 4am AEST for all the official news on the iPhone 5S and iPhone 5C as it breaks.

• In the meantime, here's all the latest on the iPhone 5S and iPhone 5C for your enjoyment

While it may be on the road to Redmond, that's not going to stop Nokia launching its first Windows 'Phablet' in the form of the Lumia 1520 which has come out of hiding in a big way.

The Verge got its hands on an album's worth of photos of the thing, with the Lumia 1520 seemingly boasting a 6-inch screen capable of 1080p Full HD playback.

The tipster responsible also reckons the handset will come with 2GB of RAM, a Qualcomm Snapdragon 800 processor, 32GB of on-board memory and an SD slot to expand that out.

Camera talk

Peering at the photos reveals that traditional Nokia Lumia rounded-corner styling, an array of buttons on the edges of the handset, a front-facing camera of indeterminate megapixellage and a slightly protruding rear-facing PureView snapper too.

That camera isn't expected to be quite as heavy on the megapixels as the Nokia Lumia 1020's 41MP sensor.

We've heard tell of the Lumia 1520 before too: the upcoming device was codenamed Nokia Bandit until scourge of mobile phone secret keepers @evleaks let slip that "Nokia Bandit = Lumia 1520" on Twitter.

No official word on when the Lumia 1520 will officially become official, but you might want to keep an eye on September 26.

• How will the Lumia 1520 measure up to the snap-happy 1020? Prime yourself with the Lumia 1020 review