This post may contain affiliate links and we may earn a small commission when you click on the links at no extra cost to you. As an amazon affiliate, we earn from qualifying purchases. Learn more from the privacy policy page
An inverter is a device that takes power from battery-operated electronics and converts it to the voltage used in your car, typically around 120 volts.
The wattage capacity of an inverter determines the number of devices it can handle simultaneously. Unfortunately, most extension cords are too short to plug all your 120-volt devices into the inverter.
But fear not, as other options include using multiple outlets or installing longer extension cords.
When considering what size inverter your car can handle, keep in mind that you may not know the exact power of your car’s electrical system.
However, it’s crucial to understand that a single inverter can only connect to one car battery. If your car has two 240v sockets, you’ll need an inverter rated at 500 watts to keep up with your power needs.
Inverters come in various sizes and price points, so it’s essential to buy the right size that fits your needs and budget. With the correct inverter, you’ll be able to power up your gadgets like a boss!
Table of Contents
How Big Of An Inverter Can My Car Handle?

When it comes to choosing the right size inverter, your power needs should be your main consideration. Before you rush out to buy and install an inverter, it’s crucial to determine what size you need.
This will prevent you from overtaxing your car’s electrical system, which can cause a series of issues.
When you install an inverter in your car, it can only draw as much power as your car’s electrical system allows.
Therefore, it’s essential to figure out how much power you need based on what you plan to plug into the inverter. If you only plan to use one device at a time, that’s what you need to consider.
However, the more devices you add, the more complicated the calculation becomes. But don’t worry, it’s still a relatively simple calculation that you need to make.
Manufacturers normally provide wattage information for electronic devices, but sometimes they may show amperage and voltage ratings. Once you have the wattage information, you need to add up the total to determine the minimum inverter size that will suit your needs.
However, it’s advisable to add 10-20 percent on top of your total figure before buying an inverter to ensure that you have some additional power capacity.
With the right-sized inverter, you can power your devices with confidence, knowing that your car’s electrical system is protected.
How To Determine The Perfect Inverter To Use For Your Car
To determine the appropriate size of the inverter, you should consider the power needs of the devices you want to use with it.
Devices like printers, TVs, light bulbs, and laptops all have different wattage requirements. You can add up the wattage of each device to find the total power you need.
For example, a printer uses 50 watts, an LCD TV uses 250 watts, a light bulb uses 100 watts, and a laptop uses 90 watts. If you add these up, you get a total of 490 watts.
To ensure you don’t overtax your car’s electrical system, you should add a safety margin of 10-20%. In this case, adding 10% to the total wattage gives you 539 watts.
This is the minimum size of inverter you need to run all four devices simultaneously.
If you’re unsure of the power requirements of your devices, you can use the formula: Volts x Amps = Watts.
You can find the voltage and amperage information on the power brick or the device label.
If the device wattage is not listed, you can calculate it by multiplying the volts with the input amps. In any case, it’s important to purchase an inverter that can handle the total wattage of your devices, plus the safety margin.
Does A Bigger Inverter mean Better Performance?
The crux of the matter is not the size of the inverter, but rather the quality of the product.
In terms of performance, both a 1000-watt and a 2000-watt inverter can achieve the same level of efficiency. However, it’s important to check the efficiency of the inverter you’re interested in before making a purchase.
To determine the efficiency of a particular inverter, you can use the Power Factor (PF) or Power Quality (PQ) which is expressed as a percentage.
For instance, a 700-watt inverter with a PF of 0.7 would produce 600 watts at a full-rated load. Therefore, it’s crucial to consider the PF or PQ of an inverter as it directly impacts its overall efficiency.
It’s not the size of the inverter that matters but rather its efficiency, which can be measured using the PF or PQ.
Therefore, it’s recommended to research and compare the efficiency of various inverters before making a purchase to ensure that you are getting a high-quality product that can meet your needs.
Factors That Influence The Size Of The Inverter Needed To Power Your car?
When selecting an inverter for your car, it’s crucial to consider several factors that can affect the size of the inverter you can use. Here’s a comprehensive list of those factors:
- Power demand: The power demand of the gadgets in your car and the car’s power are significant factors. The total wattage requirements of the devices you want to power through the inverter determine the power demand.
- Load: Smaller car battery voltage can’t handle a more significant load. The total load determines the car battery size, so it’s essential to consider the size of your car battery before selecting the inverter size.
- Size: The size of your car also affects the size of the inverter you can use. Bigger cars have bigger batteries, which means they can handle more power. Therefore, a larger inverter can be used to power gadgets in a bigger car.
- Weight: Car batteries are heavy, and an inverter must be powerful enough to lift the weight. If the inverter is not strong enough, it could damage your car’s battery or even fail to work properly.
Considering all of these factors is important when choosing the size of the inverter for your car. A reliable inverter should have sufficient power to handle the load, be compatible with the car’s battery size, and be sturdy enough to lift the car’s battery weight.
By doing so, you’ll ensure that your car’s gadgets are powered safely and efficiently.
What Are The Risks Of Using An Inverter That Is “Too Big”?
Using an inverter that is too big can pose several risks, here are the risks that may arise:
- Overloading: The inverter may draw more power than the electrical system or battery bank can handle, causing it to overload and potentially fail. This can result in damage to the inverter, battery, or other components in the system.
- Inefficiencies and increased energy waste: Using a larger inverter than necessary can lead to inefficiencies and increased energy waste, as the excess capacity is not being utilized. This can lead to higher energy costs and reduced battery life.
- Higher cost, weight, and bulk: A larger inverter may also be more expensive, heavier, and bulkier than a smaller inverter, making it less practical for certain applications.
Therefore, it’s crucial to choose an inverter that is appropriately sized for the intended use to ensure optimal performance and avoid any potential risks.
How Long Does A Car Battery Take To Run On A 300-Watt Inverter?
The size of the power inverter does not directly impact how long the battery lasts when in use.
Instead, factors such as the vehicle’s RPM and load size determine the battery’s longevity. It’s worth noting that a typical car battery operates at 12 volts and has a capacity that ranges between 600 to 900 watts per hour or 50-75 amps per hour.
To extend the life of your battery, you can follow these guidelines:
- Confirm the specifications of your alternator to determine the current it provides. This information will help you understand how much power you can safely draw from the battery without damaging it.
- When connecting higher loads, such as power-hungry devices, ensure that the RPM is above 1500 and that you are driving at a higher speed. This will help ensure that the battery is not overworked and that the alternator can provide enough current to keep the battery charged.
- For smaller loads, such as charging a phone or running a small appliance, use a slower speed and aim to power loads that are between 120 and 150 watts. This will help reduce the load on the battery and prevent it from discharging too quickly.
By following the mentioned guidelines, you can help ensure that your car battery lasts for as long as possible and that you don’t end up stranded with a dead battery when you need it most.
5 Best Power Inverters You Need For Your Car
Bestek 300W Power inverter

Fast Charging: two 110V AC outlets for charging larger devices such as laptops and tablets, 2 USB charging ports (0-2.4A) for powering USB compatible devices, a good choice as requisite car accessories
Ultra Compact and Lightweight: iPhone-sized design ideal for use on vacations, work trips, and camping.
24-inch cigarette lighter plug makes the power inverter can be plugged into almost any vehicle
Cobra 500W Power Inverter

500W CONTINUOUS / 1000W PEAK POWER – With 500 Watts of Modified Sine Wave power, you’ll be able to charge and power your smartphones, laptops, entertainment devices, small-sized appliances, and other mobile devices – safely and reliably.
COBRA REMOTE CONTROLLER COMPATIBLE – Monitor and charge devices with Fast Charge USB from anywhere inside your vehicle. The remote includes 3.0 AMP USB-A and USB-C fast charge ports
FOVAL 150W Car Power Inverter

Premium 150w car power inverter with 2 USB ports and 1 AC outlet.
Dual USB ports can charge most phones and tablets simultaneously (Max 3.1A total output), while AC outlets are great for Christmas gifts, charging string lights, laptops, breast pumps, CPAP machines, nebulizers, game consoles, kindle, TV, DVD players, lights, iPad, and other electronic devices
Travel kit: just about credit card size – 3.2 x 2.5 x 1.5 inches, space-saving and easy storage, with aluminum shell design, extremely portable and lightweight at only 8 oz+
GEARGO 600W Car Inverter

Provides 600 watts of continuous DC to AC power and 800 watts of peak power.
Fast Charging: This car power inverter features dual 110V AC outlets and 2 USB ports, great for charging string lights, laptops, breast pumps, CPAP machines, neutralizers, game consoles, kindle, DVD players, lights, and other electronic devices.
Schumacher XI41B Power Inverter

Converts 410 watts continuous/820 peak watts DC vehicle power to 120V AC household power; compatible with mobile devices, tablets, and USB devices
Allows you to use your AC products and devices through DC plug-in power on the road or wherever you are parked
Simple controls and on/off switch; LED light indicator alerts you when power is connected and converted
Benefits of Having a Power Inverter in Your Car?
A power inverter for your car is a useful device that allows you to convert the DC power from your vehicle’s battery into AC power, providing you with a 120V AC power source on the go.
Some of the benefits of using a power inverter include:
- Charging laptops and electronics from anywhere: With a power inverter, you can charge your laptop, tablet, or smartphone from the comfort of your car, no matter where you are. This is especially handy during long road trips or when you need to stay connected while on the go.
- Emergency power source: A power inverter can also be used as an emergency power source during blackouts or other emergencies. This is especially helpful if you need to power essential electronics or medical equipment in your car during a power outage.
- Entertainment devices: A power inverter is perfect for powering devices such as DVD players, high-end audio equipment, and other entertainment devices for your car. This can help make long road trips more enjoyable for everyone.
- Outdoor activities: If you enjoy hiking, camping, or other outdoor activities, a power inverter can provide a reliable power source for your electronic devices. You can charge your phone, run small appliances, or power a small radio, ensuring that you stay connected and safe while enjoying the great outdoors.
When buying a power inverter, it’s important to consider factors such as the inverter’s size, capacity, and efficiency.
You should also ensure that the inverter is compatible with your car’s battery and electrical system to avoid any damage or compatibility issues.
With the right power inverter, you can enjoy the benefits of a reliable AC power source wherever you go.
Can Power Inverters Cause Damage To Cars?
Normally, a car battery can last anywhere from 2 to 6 years depending on the conditions. However, inverter lifespan can vary depending on various factors, such as climate and the frequency of energy bursts.
When using a power inverter for your car, it’s important to take certain precautions to prevent damage to your car battery.
Firstly, it’s actually important to ensure that the power inverter is the right size and capacity for your vehicle’s battery and electrical system. Using an inverter that is too large or powerful for your car’s battery can result in an excessive drain on the battery, potentially shortening its lifespan.
Another precaution you can take is to limit the usage of high-power devices or appliances, especially when the car is not running.
Running high-power devices can put a heavy strain on the battery, leading to a faster discharge and reducing the overall lifespan of the battery.
It’s also important to make sure that the power inverter is turned off when the car is not in use. This is because inverters continue to draw a small amount of power even when they are not in use, and this can lead to a further drain on the battery over time.
And to help extend the life of your car battery, it’s recommended to maintain it properly by regularly checking the water levels, cleaning the terminals, and keeping it fully charged.
A well-maintained battery is less likely to suffer damage or a shortened lifespan due to the use of a power inverter.
FAQs
Where Can I Install The Inverter In My Car?
To install an inverter in your car, you need to connect it to the fuse box.
You can find the fuse box under the hood of your car, and you should ensure there is enough space to run wires through the car’s mechanical components. When installing the inverter, it’s important to use a new fuse to ensure proper functioning and safety.
What Is The Power Supply Duration Of A Power Inverter?
The length of time that your power inverter can provide power is dependent on the type of batteries and devices you use with it.
For a longer-lasting power supply, it’s recommended to invest in a high-quality power inverter that’s compatible with a 12-volt capacity battery. Choosing a reliable and efficient inverter model can help you enjoy a longer and more consistent power supply.
Do Power Inverters Emit Any Heat?
It is a common occurrence for power inverters to generate heat while in use, which is why it’s recommended to install a thermal fan within the inverter to help keep it cool.
How Long Does The Car Battery Use To Operate The Inverter?
The amount of time you can use your power inverter is determined by the amp rating of your car battery.
For example, if your battery has a capacity of 90 amp-hours, you can run an inverter with a continuous load of around 400 watts for at least two hours.
Can A Power Inverter Drain Car Battery Quickly?
Using a power inverter without the engine running can quickly drain the battery. However, the battery won’t be drained when driving the vehicle with the inverter.
So, it’s best to use the inverter while driving and not worry about battery drainage.
Wrapping it up -How Big Of An Inverter Can My Car Handle
Inverters convert DC power from a car battery to AC power. The inverter’s power output depends on its size and the car’s capacity.
Remember to adhere to the information written in this post. By using your power inverter properly, you can power your electronics safely while protecting your car battery.