It’s happened to us all – that moment when you’re travelling back from a meeting or an event and need to send check email, complete a report, update social media, or something else that just can’t wait…

… and the screen goes black.

You try giving it a shake or a tap to no avail, before resigning yourself to the fact that it’s flat. Dead. Kaput.

At best it’s just a frustration that will pass. At worse you could miss an important deadline, annoy a client by not responding, or neglect a potential new client’s enquiry.

So we’re bringing you the five best portable battery charging gadgets (plus a futuristic bonus one) to make sure your dead battery nightmares are a thing of the past …

Powergen battery pack1. Powergen PGMPP6000 External Battery Pack, £22

I can personally vouch for this one. It’s saved me a couple of times whilst I’ve been travelling, both from a work perspective and when lost in the wilderness using mobile navigation – in fact without it, I may still be in the middle of the Costa Rican jungle!

Works with iPhone’s, Samsung, HTC, Nexus, Motorola. It’s small, lightweight and will extend the life of your phone with up to 35 hours of talk time, giving you more than enough time to finish off those last bits of work whilst on the move.

Powermonkey Discovery2. Powertraveller Powermonkey Discovery, £48

A modern sleek lightweight charger that works on all smartphones, Apple devices (with Apple tail add-on) and tablets.

This is probably the most robust and powerful battery re-charger on our list. Fully charging your device in just 3 hours and it can do this three times before needing charging itself. Dead battery nightmares really are a thing of the past with this neat little gadget!

Pebble charger3. Veho VPP-002-SSP Pebble Smartstick, £15

This is a great, lipstick-sized option that can literally fit in your handbag and stay there without being noticed – so no excuse to leave it at home!

At just £15 it’s also great value. It can charge a flat smartphone or iPhone to around 80% charge, so will definitely get you out of those moments when you need to send just one more email!

Monster Powercard4. Monster PowerCard, £40

Whilst it’s not quite the marketed credit-card slim size, it is small enough to slip into an inner pocket of your bag with ease making it ultra-portable and perfect for travelling.

It charges fast, in under an hour, and will give around 50% life to a completely dead smartphone.

Technet PowerBank5. TeckNet POWER BANK iEP1200, £14

Works for pretty much all mobile devices including tablets, this powerhouse of a charger will restore up to 90% charge on a completely dead phone, and it can be used roughly 3 times without need charging itself.

Although slightly bulkier than others, it’s still a manageable size to drop into your bag and forget about it until needed.

And here’s our futuristic bonus option …

6. Shouting

Yes really! Shouting may be the answer to your low battery moments in the future.

Researchers at the Queen Mary University of London have come up with a novel way of using zinc oxide to convert vibrations caused by sound into electricity.

The device researchers have created to date is roughly the same size as a Nokia Lumia 925 and can generate 5 volts – enough to charge a mobile phone.

So when your kids are screaming or the guy sitting next to you on the train is listening to music loud enough to entertain the entire carriage, you could use it to your advantage!

We’ve done the research, so what are you waiting for, get yourself some battery backup now!