Nice design, but not fit for purpose

The Life: The career-saving benefits of a spare battery pack are not to be sniffed at. However, the trade-off between design and utility is crucial in choosing a charger.

The Powertraveller Powermonkey Discovery Portable Charger is available for Dh400 from Tejuri.com. Photo by The National

The career-saving benefits of a spare battery pack are not to be sniffed at. However, the trade-off between design and utility is crucial in choosing a charger.

The Powertraveller Powermonkey Discovery Portable Charger (Dh400 from Tejuri.com) wins points for its design, but fails to live up to expectations on charging capacity.

Since running out of battery is pretty much the worst preventable situation that can befall the average financial journalist, a reliable battery pack is worth its weight in gold.

The design is great. It's small, sleek and weighs about as much as an iPod.

A supplied USB cable with an assortment of different charger heads means the Powermonkey is as happy with old Nokias as with the latest Android smartphones.

To charge the Powermonkey, you simply remove the charger head, then connect the same cable's USB port to a desktop or laptop. It's incredibly straightforward and makes a great first impression.

The flipside of that is that the features are somewhat limited.

You can only charge one device at a time, and you are prevented from charging at a mains unless you are also carrying around a USB-enabled plug.

But those niggles pale in comparison to the main problem: the Powermonkey really struggles to charge a smartphone.

In fairness, the Samsung Galaxy S3 that I was testing is a power-hungry glutton that causes the electricity grids of most developing nations to tremble with fear. Even with most of the bells and whistles turned off, its battery rarely lasts for more than a day of use.

Throughout a month of testing, I rarely was able to get the Powermonkey charger to squeeze more than around 20 per cent extra battery life out of my Samsung.

Handy in an emergency, definitely, but not enough to rely on for a day on the road. Not only that, there were frequent occasions when the pack refused to charge altogether.

Then there was this gem:

"The charging source connected to your BlackBerry device cannot charge your battery," read the error message that popped up on my Curve 9360 (it later changed its mind and was recharged very quickly).

Weirdly, the USB cable was perfectly content to charge the device when plugged into a laptop. In all, the Powermonkey failed to live up to its promise. It might just stave off catastrophic equipment failure at the right time. But then again, it might not.

Which rather strips the Powermonkey of its raison d'être and makes it difficult to recommend.