We’ve been extolling the virtues of portable battery packs for a while now, but they’re not always as portable as we would like. The Dubleup aims to change that. This is the smallest power bank we’ve ever used. It measures 86 x 54 x 5.5 mm and weighs just 40g. That makes it almost exactly the same dimensions as a credit card, just a bit fatter, so it genuinely fits in a wallet or purse.
It also has a slide out MicroUSB or Lightning connector with a very short cable built into the top. There’s a MicroUSB port on the side to charge it up. Press the power button on the back to kick off charging and also light up the LED array. There are three white LEDs to give you an idea of remaining charge.
You may be wondering how much power you can fit into such a small package. The capacity of the Dubleup is 1,280mAh. To give you a couple of reference points, the iPhone 7 has a 1,960mAh battery in it and the Galaxy S7 sports a 3,000mAh battery. So, the Dubleup isn’t really going to give you a full charge, but it will certainly give you a decent burst of extra power when you need it, which could be enough to see you through.
We tested it out with a Samsung Galaxy S7 Edge, which has a whopping 3,600mAh battery in it. Straight out of the box, the Dubleup took the battery from 41 percent up to 54 percent in 20 minutes. The official power output is 5V/1A and the Dubleup itself charges at the same rate when you plug it in, so it takes around two hours to fully charge. You can charge it up with any charger you have lying around or plug it into a computer or laptop to charge.
After recharging the Dubleup, which took just under two hours, we tried it again. This time it took the Galaxy S7 Edge’s battery from 52 percent up to 74 percent in half an hour.
One concern you might have with something so thin is safety. We found that the Dubleup got pretty warm when it was charging the S7 Edge, but nothing out of the ordinary for a power bank. The Lightning connector version has been approved by Apple, so it has MFi certification.
We can’t speak to its longevity, but the manufacturer is suggesting it should provide in excess of 500 charge cycles, which is in line with most other power banks.
The Dubleup power bank is available on Kickstarter right now. If you’re quick you can snag one for $50. That’s quite expensive for a power bank with a low capacity, but you’re really paying for the portability here. If you miss out on the Early Bird offer, then the price will rise to $59.