Cyntur JumperPack Mini can jump-start your car or just your phone

Starting at $100

The Cyntur JumperPack Mini is a portable jump starter for your car that can be charged up, tossed into a glove compartment, and used to crank up a car with a drained battery.

This orange-and-black box is just a bit smaller than a VHS cassette. In more specific terms, it's 6.0 inches long by 3.3 inches wide and 1.3 inches thick. It ships with a zippered carry case, a pair of SafeJump battery clamps, and an AC charger.

Within the shell is little more than a 12,000mAh lithium ion battery pack and a bit of circuitry to control charging and discharging of that battery pack. With 250 cranking amps of output, Cyntur reckons that that the JumperPack Mini can turn over a V-8 engine and should be able to fire off 25 back-to-back jump starts. We don't have enough cars to test this claim.

The Mini charges with an included AC adapter in about 4 hours and should hold its charge for up to a year of storage. A four-LED charge indicator indicates battery level while charging or on demand when the Cyntur's function button is pressed.

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Four LEDs and a function button indicate the JumperPack Mini's charge state. Antuan Goodwin/CNET

The battery clamps connect to the Mini with a two pin connection and to the disabled vehicle with spring loaded grips. Wired inline is "SafeJump" circuitry that prevents reverse connections. Accidentally switch the negative and positive terminals and the flow of power is stopped. Connect them properly and the power flows to the host vehicle's electrical system and the car should crank.

The Cyntur JumperPack Mini hides all of its connection points under a plastic door at one end. When the door is shut, the Mini is IPX3 weather-proof, which should protect it from being rained on or splashed with water.

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Ports for charging, jump-starting, and USB devices are hidden under a weather-proof flap. Antuan Goodwin/CNET

Beneath the door are the two-pin connection for the battery clamps and the charging point. Here you'll also find a single 2.1-amp, 5-volt powered USB port that enables the Mini to charges a mobile device, such as a phone or tablet, when its not being used for emergency jump starts. Tapping the Function button to display the battery charge level also activates the USB port for charging.

With a full 12,000mAh charge, the Mini should be able to should be able to charge five smartphones like the Nexus 5, four phablets like the iPhone 6 Plus, or a tablet like the iPad Air 1.3 times...in theory. Since most mobile devices power themselves on while charging and drawing power, you'll likely see a bit less than this in practice.

The business end of the Mini is also home to a 200 lumen LED flashlight that is activated by holding the Function button. The flashlight is quite bright -- don't stare right into it -- and also features an emergency strobe mode.

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An LED flashight with a strobe mode could prove useful in emergencies. Antuan Goodwin/CNET

The Cyntur JumperPack Mini is a simple product, so there's not much to our evaluation. It works. I was able to jump start CNET's test car, a Chevrolet Aveo hatchback that had its battery intentionally drained. I was also able to charge both a Nexus 5 smartphone and a Sony digital camera when traveling with the Mini battery pack.

About the only thing that I wasn't able to test was Cyntur's claim that the JumperPack Mini will hold its charge for a year. On one occasion during close to a month of testing, I pulled the JumperPack Mini out of my backpack and found that its charge had been depleted, thanks to an accidental activation of the LED flashlight. To be fair, this could have been avoided by carrying the Mini in its zippered carrying case.

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The JumperPack Mini, the battery clamps, and AC charger all store in a zippered case. Antuan Goodwin/CNET

Overall, I feel like portable jump starters are excellent safety nets against being stranded due to a drained battery. The Cyntur JumperPack Mini works as advertised and would make a solid addition to a glove box or trunk toolkit.

At $99, the Mini is significantly more expensive than a $30 set of jumper cables, but also takes up less space in the car and does not require a second healthy vehicle to draw power from, which may not always be available. And with a roadside assistance jump start from, for example, a service like Urgent.ly ringing up at around $75, the Cyntur JumperPack Mini could pay for itself with just one save.