Best power inverter for car: A mechanic’s guide and review

(Last Updated On: March 13, 2024)

Has your phone’s battery ever depleted when you’re travelling and require it the most?

Keeping your devices charged is essential these days. Either if you are a working person who spends a lot of time in the car, or just enjoying a chilled camping trip. A power inverter will help keep all your devices charged up.

Buying a power inverter might seem a daunting prospect at first. But I will guide you through the best power inverter for cars and help you make the correct decision.

Power inverter 101

First, we need to learn some basics about power inverters. I know you are eager to jump into buying one right away. But trust me, this will greatly help you make the correct purchase decision.

Power inverter vs. power converter

You may have come across power inverters and power converters before. A power converter is an electrical device that converts electrical voltage from AC to DC. They commonly call these battery chargers. Think of converters as the devices you need to charge up your car’s battery when it is dead. Converters take electricity from a 110V current to charge appliances that run on 12V power. These are mostly used to charge up batteries.

A power inverter is an electrical device that converts electrical power from DC to AC. These switch the power from 12V to 110V AC and use 110V power from 12V batteries. Think of a power inverter as a 12V cigarette lighter socket system. An inverter works by stepping up the battery power to power your devices and appliances. Using AC-powered devices and appliances in your car will need an inverter.

So, to put it simply:

  • Power converter: Convert AC to DC, basically a battery charger.
  • Power inverter: Convert DC to AC, use battery’s energy to power up other devices.

“Modified sine wave” vs. “Pure sine wave”: Which one is better?

Ah, the eternal question of every power inverter user. You may be also asking yourself: What is a sine wave and why is it important anyway?

A sine wave is the usual waveform of AC in most electrical circuits. It is S-shaped in form and they typically alternate at higher frequencies. So how do these different types of sine waves impact our electronic devices?

  • Modified sine wave puts less stress on charging devices. They’re usually cheaper and they’re ideal for smaller electronic devices such as portable power banks and smartphones.
  • Pure sine wave is more expensive but can charge any type of electrical device or appliance. They are also more powerful and can even provide similar power to your electric grid. These types of power inverters are compatible with just about any device, such as laptops and other sensitive electronic equipment.

If you’re still not sure about which type of inverter should you pick, ask yourself these three questions:

  1. Do my devices use a motor?
  2. Are my devices medical equipment?
  3. Do my devices use a rectifier?

If your answer is yes to either of those questions, especially the second one, you may need a pure sine wave power inverter.

If it’s a no to all three of them, then you’ll likely be just fine with a modified sine wave inverter.

And if you’re still not even 100% sure, you can always check with the manufacturer.

Read more about Sine Wave »

How to choose the best power inverter for your car

Choose from the top brands

Which are the top power inverter brands on the market? There are hundreds of different ones, but the most recommended in independent reviews and tests are from these top brands:


Bestek is renowned for its automotive accessories, household appliances, and workshop tools. They have branches in the USA, United Kingdom, and Japan, and distribute their products across the globe. This company offers comprehensive factory warranties and has a high customer satisfaction and service record.


Krieger is best known for its solar power products. This German brand is headquartered in the USA and offers products to consumers in energy generation for end-users. Krieger operates in dozens of countries with a special focus on the United States, Europe, South Africa, and Asia. Customers have rated them highly in customer service surveys, and their warranties and return policies are clear and helpful for customers.


Energizer is the world’s largest name in battery technology. It is headquartered in Missouri and distributes its products to more than 150 countries around the world. It is best known for its batteries and battery technology, which it has transferred to creating a line of low-cost, high-quality power inverters to suit a wide range of purposes and users’ needs.


Foval is a company best known for its automotive accessories. This Chinese company offers a range of products, including cell phones, and low prices. They distribute their catalog of high-quality products to over 100 countries.

Look at the important aspects


A power inverter can be classed according to the type of sine wave it generates and by the wattage it produces. Why do you need to know the wattage output of your power inverter? It means you can charge up and power more than one device or appliance at the same time. For everyday devices such as small electronics, an inverter with 150 to 300 watts will be more than adequate. For larger devices for camping, you’ll need an inverter with 1,000 or more watts. To break it down, using a smartphone and your laptop plugged into your power inverter will use about 90 watts of power. A laptop uses between 50 and 80 watts and a smartphone draws about 5 watts of power to recharge.

Some power tools require 100 watts or more. Most camping and cooking equipment also draws more than 120 watts each. For such uses, you’d be best served by a more powerful inverter. Inverters are available with outputs ranging from 150 watts to 5,000 watts.

Remember that powering up more devices from your inverter means that your vehicle’s battery will drain faster. You’ll need to run your car’s engine and start it more frequently the more you use your power inverter. Generally, using a power inverter with less than 1,000 watts will drain your car’s battery in 60 to 90 minutes. Larger power output inverters can drain your vehicle’s battery in 30 to 60 minutes. It would be advisable to run your car’s engine every 30 minutes to recharge its battery.


I know guys tend to say this a lot, but bigger isn’t always better, as long as it’s doing its job.

The ideal size of a power inverter should be about as large as your smartphone. For everyday charging and use, some power inverters are even designed to fit into your car’s drinks holder. Larger power output inverters can also be stored in your vehicle’s glove box with ease.

Another aspect of the size of the power inverter to consider is that smaller power inverters usually have one USB port and one plug outlet. Larger inverters are equipped with more outlets and LCD screens so you can better manage your power usage. Carefully assess the number of devices you need to charge at once to better understand the size of the inverter you need.


Power inverters come in various designs. The best power inverters feature durable metal housings and temperature-controlled cooling fans to prevent overheating. Power inverters’ designs include one or more USB ports and one or more 110V AC power outlets. They have 12V cigarette lighter sockets for plugging into your car’s electrical system. Larger power inverters feature digital readouts so that you can learn how much power you have consumed from the inverter. This helps you know when you need to charge your car’s battery before it goes dead.

Safety measures

Most power inverters feature surge protection to protect electronic equipment. Search for products with ETL stickers: this means they have been certified for use in the USA. Apart from built-in surge protection, they also feature systems that protect the power inverter against overloading, overheating, and electrical shorts. In terms of overheating, we’ve mentioned that power inverters are equipped with temperature-controlled fans to protect the device.

As with all electrical products and devices, you need to handle a power inverter with care. Damage to the power inverter can cause electrical short circuits and become a fire hazard. The higher the power output, the higher the risk of injury if something goes wrong. 110V can seriously injure or kill someone, so care and diligence need to be paid when using a power inverter.

Number of ports

Considering the number of ports you need on your power inverter will determine how many devices you can charge at the same time. Most power inverters feature one USB port and one AC outlet for you to charge your laptop and smartphone. If you’d like to power more devices simultaneously, you will need to invest in a more powerful inverter with a higher wattage and more ports.


Power inverters are constructed to exacting standards to meet strict guidelines for safety certification. One of these safety systems is built-in thermal fans. When loaded with devices, power inverters can become hot and noisy. Temperature-controlled fans spring into action when the device becomes hot and works to cool it down.

The best power inverters can last for 5 to 10 years of regular use when carefully maintained.

Top 4 power inverters for car

Tim’s Pro-Choice: Bestek 300W

bestek 300w
Bestek 300W
The Bestek 300W power inverter offers the best quality product at the best price. With excellent quality and more than enough power output for your everyday needs.


  • Compact design
  • Temperature-controlled cooling fan
  • 2.4A USB quick charge port
  • Overloading protection


  • Fuse is VERY hard to replace

The Bestek 300W is my choice as the best power inverter. There are two versions of this fantastic product, one with a modified sine wave and one with a pure sine wave.

Both versions of this model feature an aluminum alloy housing, two USB ports, and two 110V AC outlets. They are also equipped with cooling fans, isolation voltage protection, and a quick charge 2.4A USB port.

The Bestek 300W power inverter is rated for 300 watts of power and provides a peak at 700 watts. A durable cigarette lighter socket features a secure buckle design to create a stable current for your power inverter.

It is no larger than an iPhone in size to make it compact and easy to transport. The housing is solidly constructed and meets all the safety requirements with its protections against overloading and overheating. It also boasts protections against overcharging, over-voltage charging, under-voltage charging, and shorting. For further peace of mind, each model is backed up with an 18-month factory warranty.

The pure sine wave version reduces battery power consumption by 40-percent. That means you can run your devices for longer without the need to start your car’s engine.

Unfortunately, nothing is perfect, and neither is Bestek 300W. Many buyers have complained about how irritating it is to replace the unit’s fuse once it’s blown. The silver lining is that Bestek designed their 300W unit well enough so that fuse-blowing rarely happens. We can only hope that Bestek will improve this problem in the future.


The Bestek 300W power inverter – in both versions – offers the best quality product at the best price. For everyday use, this product can not be beaten in any way. Both versions are ultra-compact in size and easy to use, marking the Bestek 300W as the best choice you can make. Quality, low price, and more than enough power output: this is Tim’s Pro-Choice of today’s winner.

Best pure sine wave power inverter: Energizer 150 Watts

Energizer 150 Watts
Energizer 150 Watts
You can’t really go wrong with Energizer’s products. Especially when it comes to battery and battery related things.


  • Dual placement
  • Pure sine wave
  • 3.0 USB quick charge
  • ETL certification


  • Power plug can be fidgety and may interrupt power

Energizer’s 150 Watts pure sine wave power inverter provides an AC 110V outlet and 2 USB ports. One of those USB ports boasts a Quick Charge 3.0 system. This device delivers 150 continuous watts and 300 peak watts from its 12V cigarette lighter socket.

In terms of size, it is as big as a regular smartphone and can fit into your vehicle’s cup holder. The pure sine wave electrical current provides a stable and reliable power source for you to safely charge your laptop.

It features low-voltage protection, high-voltage protection, short-circuiting, overload, and overheating protection. It is sold with a 2-year factory warranty.

The body of the unit is ruggedly built with hard-wearing plastics and bump absorption zones to protect its internal components.


This is the best pure sine wave power inverter your money can buy. Energizer 150W offers everyday practicality to power your sensitive electronic equipment and accessories. It is also small enough to be stored in your vehicle’s drinks holder and can power three devices at the same time. It is easy to see why this is the most popular pure sine wave inverter on the market.

Most powerful: Krieger 2000 Watts

Krieger 2000 Watts
Krieger 2000 Watts
What else can I say? Big wattage equals big power. Go for Krierger if you plan to power bigger devices.


  • MET Approved for heavy-duty applications
  • Has remote control
  • Comes with a full hardware kit


  • No cigarette lighter socket!

The Krieger 2000 Watts power inverter takes the top spots in my comparison tests in terms of power outputs. No other power inverters match this model in terms of quality for the price. This unit features LCD readouts that show input watts, output watts, and the battery’s level. The remote control is an added feature to make it easier to control the device on/off functions. Krieger 2000 Watts offers modified sine wave electrical current.

One Krieger 2000 Watts hardware kit features:

  • One 3-foot long battery cable
  • 1 Ultra-silent temperature-controlled fans
  • 2 AC 110V outlets
  • 2 USB ports

All of those are controlled and protected by Krieger’s “Smart Chips” Technology. The unit is MET Approved for heavy-duty use. Packaged with Hardwire Kits, you can connect these power inverters directly to your vehicle’s battery.

Now it’s time to address the elephant in the room, or more accurately, the lack of it. For some reason, this unit does not have a cigarette lighter socket!

I know, I know. This can be either really, really good or really, really bad; it depends on each person. But come on, Krieger. This is a free country! At least give your users a choice to smoke or not to smoke in the car when they buy your products!


The Krieger models have won my Most Powerful category because of their Hardwire Kit and heavy-duty ratings. Their 3-year factory warranty is the icing on the cake. They’re undoubtedly built strong to deliver high power outputs to run all your campsite’s electrical needs, and more. Just remember though that the more power you use, the quicker your car’s battery will drain.

Most portable: Foval 150W

Foval 150W
Foval 150W
This thing is ridiculously compact; it should be illegal! Foval is the ideal unit for your car’s minimal set up.


  • Ultra-compact
  • Still has room for LED indicators
  • Surprisingly stable modified sine wave power output


  • Fan is quite weak and can cause overheat

The Foval 150W power inverter is available in two color versions (red and blue). This device weighs just 7 oz and is the same size as a credit card. It measures 3.7” by 2.5” and is 1.5” in height, making it a clear winner as the Most Portable power inverter in my comparison review. Despite its tiny dimensions, it packs a punch: it provides 150 watts of continuous power and 300 watts peak output. It features 2 USB ports and an AC 110V outlet. The unit also plugs into your vehicle’s cigarette lighter socket with ease.

Foval 150W is constructed with a durable metal housing to protect its internal components from damage. It also sports an ultra-silent thermal fan which is nice and quiet but also feels a bit underwhelming in terms of cooling. This Foval 150W power inverter also offers protection from short-circuiting, low-voltage, overcharging, overvoltage, and has a built-in fuse.

The sheer size of this device and its portability cannot be underestimated. It is small enough to keep in your shirt pocket, laptop bag, or vehicle’s glove box to make it an excellent travel companion.


The Foval 150W offers unbeatable portability and versatility in a size no larger than a credit card, yet compromises zero in terms of power output. When you’re on the road, this little power inverter will easily keep your laptop, smartphone and other electric devices and gadgets charged up and powered on. You can transport and store this device in handbags, laptop bags, and in your car’s glove box with no fuss. It truly is the most portable power inverter with real power you can rely on to keep your devices charged up.


1. Will a power inverter harm my battery?

No. Only you would! If you use your power inverter incorrectly, it will damage the car’s battery. Following manufacturer’s instructions carefully and it will not damage the vehicle battery in any way.

2. What size power inverter do I need to run a TV?

You will require a power inverter with more than 150 watts output to run a TV.

3. Can a car power inverter run a refrigerator?

A power inverter with a peak rating of at least 600 watts is required to run a fridge.

2 thoughts on “Best power inverter for car: A mechanic’s guide and review”

  1. Thanks for suggesting these power inverters for cars. If we are using an inverter in a car, we have to connect it with the cigarette lighter plug so you will not be able to get more than 150W power via the cigarette lighter plug, so this is the limitation. To get more than 150W, I think you need to use the alligator clips to connect with the battery directly.

    If you are using an inverter in car, please make sure that the car battery is not completely discharged otherwise it will not be helpful to start the car.

    Thanks for your honest reviews on these power inverters.

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