No one wants to get stranded with a dead battery and a car that won't start, then dig out the jumper cables and find another vehicle to give you a jump start. And you don't have to, as long as you own a portable jump starter.

Typically, when you have a low car battery, you'll need a pair of extra long jumper cables with clamps on both ends and a second car running to share its power with your dead car. Then, you pop the hood on both vehicles, connect the cables to both batteries, give it a minute, and start the car and hope it works.

And while that's fine, not everyone has a set of jumper cables, and you won't always be in a situation where a family member or friend can swing by to boost you. Here's how a portable jump starter works and why they're worth buying.

What is a Portable Car Jump Starter?

A portable car jump starter is exactly as the name suggests. It's a portable handheld device with enough battery capacity (and cranking amps) to successfully start a car or truck. These nifty little gadgets not only replace jumper cables, but you don't need another person to get the job done.

These devices output a large amount of power quickly and safely, enough to turn over the engine in a car.

While some larger options use a battery similar to what you'll find in an automobile, portable car jump starters like we're talking about today use lithium-ion batteries, the same type of battery in your smartphone---only bigger. It uses all that battery power to turn over the engine when your car battery is dead.

How Portable Jump Starters Work

When your car battery gets too low, even though your door or dash lights still come on, it doesn't have enough power to start the engine. When that happens, you'll need a boost. Every car battery has a cold cranking amperage (CCA) rating, which is how much amperage power it can deliver to turn over the engine. You'll need at least 150 CCA to start your average compact car, but larger trucks and SUVs often need a bigger battery offering upwards of 400-650 amps. If your battery doesn't have enough juice, you can't start the car.

For those unaware, you're not actually charging the battery when you jump-start a car, either with another vehicle or with a portable jump starter. You're essentially bypassing it and starting the car with something else.

So while a portable jump starter won't charge the battery, it'll provide the necessary power and CCAs to crank the engine and start the vehicle. Once the engine is on and running, the alternator will charge your battery.

Related: Hulkman Alpha 85 Portable Jump Starter Review: Just Buy One

For example, the HULKMAN Alpha 85 jump starter we recently reviewed has a 20,000 mAh battery inside, which is about 4x bigger than the Li-Ion battery in most phones. It's a portable battery pack that combines all the power at once to start a car. Devices like the HULKMAN have over-volt protection, reverse-polarity protection, and short-circuit protection.

Once a portable jump starter is fully charged, it's ready to go. You plug the included alligator clamp jumper cables into the battery pack, then connect the clamps to your car battery and turn on the jump starter. It'll give the vehicle enough juice so you can turn the key, start the car, and be on your way. Better yet, many of them can start your engine several times before needing a recharge.

Again, what makes these great is you don't need another vehicle and person to jump-start your car. You can do it all yourself in less than one minute.

Extra Benefits

A device that can save you from getting stranded on the side of the road is valuable in its own right, but many portable jump starters have a few extra benefits up their sleeves.

Related: Why Your Next Car Needs Adaptive Cruise Control

Considering a portable jump starter is essentially a giant battery pack, most of them do everything a regular mobile battery pack can. Popular brands like NOCO or the HULKMAN linked above have built-in USB charging ports to power up your phone, laptop, and other gadgets.

So if you're stuck in a situation where both your car and phone have a dead battery, this gadget can fix both problems. Charge your phone and call for roadside assistance, or hook the jump starter up to your car, boost it, and hit the road.

Additionally, many portable car jump starters come equipped with LED lights that double as a flashlight, lantern, or flashing SOS lights in the case of an emergency. Use it like a lantern while you're changing a flat tire on the side of the road. Some even have integrated air compressors. Neat, right?

Is a Portable Car Jump Starter Worth Buying?

So, should you buy one and store it in your trunk? In my opinion, yes, 1000%. I have one in both of my vehicles, and my significant other has one in hers.

Most people don't realize their car battery is dead or low until it's too late, and no one wants to deal with that situation. And when it does happen, knowing that I have a fast, easy, safe solution ready to go gives me peace of mind.

And honestly, these days, I don't really want to flag down a random person on the side of the road and ask for a jump. I'd rather rely on myself, a portable jump starter, and call it a day. Then, when you combine all the other features these have to offer in one device for under $100, it's almost a no-brainer.

Just buy one, because eventually, you'll be glad you did.