Autowit Supercap 2 Jump Starter review

REVIEW – Many of us have experienced that sickening feeling of going to start our cars and hearing a nauseating clicking sound, dim lights, and weak or no crank letting us know we are about to have a bad day. With Autowit’s Supercap 2 Jump Starter in your glove box, asking strangers for jumper cables or waiting for AAA in a cold car is over.

What is it?

The Autowit Supercap 2 Jump Starter is a device that will store and deliver power to start a 12-volt vehicle with a weak or dead battery.

Hardware Specs:

  • Supercapacitor based, no batteries
  • No need for pre-charging
  • 20-year lifespan
  • -40°F (-40°C)  to +158 F (70°C) operating temperature range
  • Ultra-safe
  • Maintenance-free
  • 800Amp peak current
  • Starts gasoline engines up to 7-liters and diesel engines up to 4-liters
  • Dimensions: 51 x 6.45 x 3.89 inches
  • Weight: 3.95lbs

What’s in the Box?

  • Jump Starter
  • Alligator cables
  • Cigarette lighter cable
  • USB cable
  • Carrying Case
  • Manual

Design and Features:

A few weeks ago, my brother’s playful grandson was entertaining himself in his Jeep. Unbeknownst to my brother, play involved turning on a small light under the dash, leaving his vehicle with a dead battery the next morning. Luckily for my brother, he was home and had a battery charger handy, but had he been in a remote location, he may have been stuck. If he had been in a location without phone service, a minor inconvenience could have become a panic situation very rapidly.

My vehicle has experienced depleted batteries several times so I carry a battery-based jump starter. Unfortunately, batteries have an internal resistance that will cause them to discharge over time if unused. Depending on size, battery packs also require a few hours to recharge, and their effectiveness decreases with temperature. Supercapacitors solve many of these limitations so I was very excited to give the Autowit Supercap 2 Jump Starter a try.

The Autowit Jump starter arrived securely packaged.

I was pleasantly surprised at the inclusion of a swanky carrying case.

The Jump Starter is a bit bulkier than its battery-based counterparts, but because it doesn’t contain batteries, it’s amazingly light-weight.

Included is a pair of alligator clips for connecting to a car, motorcycle, or lawn mower battery.

Also included is a short micro-USB charging cable, but a USB power supply is not included.

…and a cigarette lighter charging cable.

All of the connections are protected by a rubbery panel on the side of the Jump Starter.

The Autowit Supercap Jumpstart 2 has three charging options: Directly from a car battery using the alligator cable, using the 12-volt cigarette lighter adapter, or charging from any USB power source. Connections under the cover include the keyed alligator cable connector, Micro-USB, and a 12-volt coax jack.

At the top of the case, a small, bright OLED display provides device status.

One difference between this Jump Starter and others is the lack of a USB output port. If your needs are double-duty as a charger as a USB battery pack and jump starter, a battery-based device would better suit your needs. The way I figure, once you get your vehicle started, you can use its electrical system to charge your phone, so for me, this isn’t a deal-breaker.

Some battery-based jump starters include an integrated LED flashlight which is lacking on the Autowit Supercap 2.

Interestingly, the Supercap 2 can even charge itself from the battery in the car you are trying to start! I know what you’re thinking.  “Wait? What? You’re confusing me.”  To ease your confusion, here’s how it works – If the battery in your “dead’ vehicle still has some juice, but not enough to crank the starter, the supercapacitors can pull some of the remaining power from the “dead’ battery, store the charge, then release the power all at once to crank the vehicle starter. Pretty slick, right?!

Should your vehicle battery be completely exhausted, you can still charge the Jump Starter using another vehicle or a USB power supply.

Another major advantage of Autowit’s technology is the speed of charging. From zero to 100% capacity on a 2.1Amp USB power supply (the same one I use to charge my phone) my wait was about ten minutes. For comparison, my battery-based jump starter took about 6 hours.

Using the Autowit Supercap 2 Jump Starter is very easy. Connect the alligator clips to the battery terminals with the red wire on the + (positive) and the black on the – (negative)…

Press the sole button to start the charging process and an internal buzzer will sound. After charging is complete, the buzzer will sound again.

To start the jump-starting process, press the button again, and the Supercap 2 will begin charging the battery and a 10-second countdown will begin. Hop in your vehicle and wait for a continuous beep from the Supercap 2 and turn the key to start the engine. This process was shockingly easy and effective.

I started my test by discharging my car battery down to 9.6-volts, well below what my little car needs to start.

Next, I attached the Supercap 2 to the battery terminals. Charging began immediately and took about 6 minutes.

After charging completed, I pressed the button triggering the 10-second countdown. When the Supercap 2 beeped, I turned the key and my car started immediately. According to my meter, the Supercap 2 delivered 154.2 Amps to start my car. Specifications state the Supercap 2 can deliver up to 800Amps.

There was no hesitation, no sputtering, no weak cranking –  my car simply started as if the battery was fully charged. In a perfect world, everything should work this well!

  What I Like:

  • Superfast charging
  • Multiple charging options
  • Extremely easy to use

What I Would Change:

  • Add a USB output port
  • Add an integrated LED flashlight to make battery connections easier in the dark.

Final Thoughts:

As Louis Pasteur said, “Fortune favors the prepared mind.” With the Autowit Supercap 2 Jump Starter handy, I’m better equipped to handle road emergencies and my sense of “what if” dread has been calmed. My mind feels more prepared and I might help someone in need without the risk of causing damage to my vehicle or battery. This product is ultra-fast, super easy to use, and could potentially save hours of frustration.

Price: $149.99
Where to buy: Amazon (Use the coupon code: gadgeteer to save 10%)
Source: The sample for this review was provided by Autowit.

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2 thoughts on “Autowit Supercap 2 Jump Starter review”




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  2. Wow, what a great product. I have a battery based jump starter that I carry on my motorcycle. Like you said, I had to charge it well over 6 hours to get it up to full capacity. We could use it twice on an S2000 my husband owned before it would die. Then we were stuck recharging it. Carrying it around on my bike, I have to remember to pull it out and recharge it every once and a while. I will have to put this on my future purchases list!

  3. I wouldn’t trust its ability to pull enough charge from a weak battery. What if the battery is actually dead? I would like to know how long it holds a charge after being fully charged. Apart from that I think using a supercapacitor is a great idea.

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