Recharge on the run!
Always running out of battery? Lindsay Handmer test 10 portable power banks that’ll let you recharge your gadgets — and even laptops — while you’re on the move.
In a world of gadgets, power banks are a great way to extend battery life. While they come in a range of sizes from models that can fit on a keyring, to those able to power a laptop or start a car, we’ve aimed for a middle ground. As the battery tech improves, 10,000mAh (or so) battery banks are highly portable, yet can still top up a phone multiple times. While we firmly believe one should be in every bag just in case, they are also worth it for occasional use, such long plane or public transport rides, or going camping.
Make sure not to leave a power bank in a hot vehicle during summer, as the high temperatures can reduce the life of the cells. It’s worth noting that there are loads of poor-quality power banks available on eBay which do not meet their claimed capacities or current outputs. To help weed out the undesirables, we’ve tested 10 power banks from known brands and compared the feature sets.
KEY FEATURES
Every power bank will suit different uses. Those who expect to be away from the grid for a longer period should consider capacities over 10,000mAh, and conversely, there are plenty of small units as well. Having two or more USB ports is ideal, but make sure at least one is rated for 2A or more of current, as this is needed to charge a tablet in a reasonable time. Qualcomm’s Quick Charge tech is a great way to charge your phone in a hurry, but it’s only supported by some power banks. To reduce clutter or lost cables, some power banks integrate a connector into the device itself. Almost all power banks will have a basic LED battery level meter, but the better ones give an actual numerical display for increased accuracy. Some power banks include other handy features, such as a built-in LED torch, waterproofing, warranty covering the charged devices.
CAPACITY RATINGS
Typically given as mAh (and sometimes Wh), power bank ratings are for the battery cells inside. The problem is that, by the time the voltage from the battery is converted to transfer over USB, then converted back to charge your device’s battery, some is lost. So while the power bank might be rated at 10,000 mAh, only 9,000mAh will actually make it into your phone. We can’t test the conversion efficiency of every phone, but we can test the power banks. We connect each to 10W load and USB power meter, and measure how much passes through. Due to normal losses, we don’t expect to see 100% — closer to 95% is normal and anything above that is excellent. But manufacturers who use better-quality battery cells, or understate the capacity, can end up with more than 100% of the rated capacity available in the real world. While not the be all and end all, it’s a good way to weed out underperforming battery banks, and gauge the quality of the cells and circuitry used.