There are times when your mobile phone battery just doesn't last long enough. If you're away from a power source for a few days, you either need to ration your mobile phone use or just give up using it when it runs out. If, like me, you go to music festivals, you have the option of paying someone quite a lot of money to charge your phone, assuming you feel comfortable with leaving it with them. What you need is a portable charger of your own.
There are some phone chargers that take ordinary AA batteries, but of course they can cost a fortune in disposable batteries. The PowerGen, which was supplied to me for review by its Amazon distributor, is the first rechargeable portable charger I've seen, and it does away with all the disadvantages of other types of external chargers.
So, when you're planning to go away, you charge your phone and you also charge the PowerGen. It charges using a USB port in about 5 hours if you use a 1 Amp supply (it holds about 5.2 Amp hours). Most computer USB ports deliver less current, and so take longer to charge it, so it's best to use a mains-to-USB adapter, such as your Kindle, iPhone or iPad mains charging accessory. I use a 3 Pin 1000mA USB Power Adapter Mains Charger
. The adapter supplied with the PowerGen is a flat 2-pin plug, which is not suitable for use in the UK without a travel adapter.
Now you have a charged PowerGen, whenever your phone starts running low on power, you plug in the PowerGen using another USB cable, press the charge button, and the power stored in the PowerGen charges your phone. For my phone, a Motorola Milestone 2 Android phone, the Powergen was able to give it three full charges, enough to keep it going for the duration of most music festivals. There was enough power left in the PowerGen to give an 80% charge to a friend's iPhone as well.
To add to the festival-going credentials of this useful little device, if you press the charge button twice, you can use the PowerGen as an LED torch.
There are two identical USB cables supplied (identical except for length - one is longer than the other) that accept a variety of plug adapters to make the PowerGen work with most devices that can be charged via USB. There are micro and mini USB, iPhone and PSP adapters (so it's not just for mobile phones!), and a selection of other adapters that I don't recognise. If you prefer, you can use the USB cable that came with your device, as the "from" end is a standard USB socket.
The PowerGen is compact enough to fit in your pocket alongside your phone. If you want to charge your phone while it's in your pocket, you need to be careful with the cable-plus-plug-adapter combination, which is a bit unwieldy, and can get twisted and unplug itself. It's fine if you're careful, and the PowerGen unit itself is robust. Four LEDs show how much charge is left in the PowerGen: each LED is roughly equivalent to an hour's charge.
The PowerGen is a simple idea that can make a big difference. It's great for festivals or if you're out of the office without access to a mains socket.
Note: I have seen other reviews that suggest that the rechargeable batteries in the PowerGen have a limited lifespan. I've only charged mine a couple of times so far and it seems fine, but I'll update this review if I see any problems. It's still likely to work out cheaper than using disposable batteries.