Editors' note: Portions of this review were copied from CNET's review of the Bolt Power D28 portable jump starter. The X-5 Mini underwent similar testing.
Portable jump starters used to be a basic car battery in a plastic casing, weighing up to 20 pounds. Now, improvements in lithium ion batteries enable a new breed of jump starter, one that can fit in your glove compartment and weighs about 10 ounces. Such is the Bolt Power X-5 Mini, a compact device with a convenient screen that's also capable of charging your smartphone.
At 5.5 inches long, 3 inches wide and well under a pound in weight, the X-5 Mini can easily be carried around in one hand. It's a little big to fit in a pocket but would fit in a car's glovebox or trunk easily enough. The X-5 Mini comes in a zippered nylon case, holding its adapter and charging cables, which add considerable size to the whole package. You might want to leave the case at home and just pack what's necessary in the car.
Contoured yellow plastic covers the top of the X-5 Mini, with cutouts for a small LCD and a power button for the integrated flashlight. The front end houses two USB ports, a port to charge the X-5 Mini's battery and the flashlight lens. One of the long sides holds the main power switch, while the other has a port for the battery clamps.
Cables included with the X-5 Mini are the battery clamp adapter and a white multijack adapter with older and newer iOS plugs and plugs for Mini- and Micro-USB. In addition, Bolt Power includes AC and 12-volt adapter cables for charging the X-5 Mini.
To charge up my iPhone 5S, I had to plug in the white multiadapter cable, or I could have used my own iPhone cable, then turned on the power switch. To further test the capabilities of the X-5 Mini, I plugged another device in to the Mini-USB plug at the same time my iPhone was connected, and the two charged simultaneously.
As the X-5 Mini's battery is rated at 8,000-mAh capacity, it could charge up my 1,900-mAh iPhone 5S battery four times over. That amount of power is enough to charge a Nexus 7 tablet a couple of times, but it falls short of the latest iPad's 11,560-mAh battery, so could provide only a partial charge. The USB port outputs power at 2.1 amps, the maximum for USB 2.0 charging.