If you own a truck or car with a diesel engine, you've more than likely experienced a vehicle that won't start, especially on one of those frigid winter mornings. While any vehicle's battery can struggle in the winter, diesel engines are particularly finicky.
And that's likely why you're reading this article. You're likely looking for the best diesel engine jump starter to start your vehicle when your batteries just won’t cooperate.
Now, let’s be honest. There are many jump starter alternatives out there, many of which are suitable for diesel engines.
However, the goal of the following guide is to help you learn about the differences between portable lithium-ion jump starters and traditional lead-acid booster packs, and what to help you look for when choosing the best jump starter for a diesel vehicle.
But before we get to that, let's take a look at why diesel engines are different than smaller cars and gas vehicles.
Why Diesel Engines Require More Powerful Jump Starters
Diesel fuel is thicker than gasoline and can actually gel up when it gets cold enough. Frigid temperatures can cause paraffin wax crystals to form in the fuel, a process called "gelling," which can temporarily clog fuel lines and filters.
Diesel engines also have higher compression ratios, which means they require more cranking amps to start.
So, even when temperatures are warmer, diesel engines still require significantly more amperage to start, which is why you need to make sure you buy a jump starter with adequate cold cranking amps to match the size of your vehicle.
Lastly, diesel vehicles also generally have larger batteries.
Some larger diesel vehicles and heavy machinery even have dual-battery systems, effectively doubling the peak amperage required to start the engine.
Therefore, it’s crucial to look for jump starters specifically rated for heavy-duty usage. RVs, heavy-duty pickups, SUVs, and most commercial trucks require higher capacity jump starters.
Pro Tip - JUMPFORCE PRO is our very own, purpose-built emergency jump starter. However, it's generally not rated for heavy-duty diesel usage. It can help boost some smaller diesel engines, but for larger, heavy-duty engines, you may want to look for a larger, heavy-duty jump starter.
What Happens If Your Jump Starter Is Too Small?
If your jump starter is too small, most likely, nothing happens! But that's the problem. You simply won't be able to jump start your vehicle.
And let me tell you, failure to crank an engine when you're standing outside in the freezing cold is nothing you want to deal with.
Using the wrong size jump starter can also cause the unit to overheat when connected to a large, higher voltage electrical system.
This is rare, and most modern jump starters have built-in features that prevent overheating. But it is possible, and you can damage your jump starters' electronics, which can even lead to premature failure of the unit.
What to Look for in Battery Jump Starters for Diesel Engines
Ultimately, you need to look for a jump starter that's the right size for your vehicle.
But it's not just about matching peak amperage or cold cranking amps. You'll also want to consider lithium-ion vs. lead-acid batteries, cable thickness and clamp size, and other cold-weather features.
Let's take a closer look.
Peak Amps Vs Starting Amps - Choosing The Right Unit To Jump Start Diesel Engines
You might be wondering whether there's a difference between peak amperage and cold-cranking amps.
And yes, there is!
Peak amperage refers to a jump starter's peak power output, which only lasts a second or two. Meanwhile, cold cranking amps refer to the device's sustained amperage or its ability to produce and sustain high amperage for 30 seconds at 32°F.
Choosing the right size jump starter for a diesel depends on the vehicle's starter draw requirements.
But, as a minimum rule of thumb for diesels, you'll want to look for jump starters that produce at least 1,500 amps.
For larger engines like 6.0L or 6.7L, and for heavy-duty diesel machinery, you may need devices that produce 2,000 to 4,000 amps.
Battery Type: Lithium Vs. Lead-Acid Jump Boxes
There are two main types of jump starters on the market today: Jump starters with lithium-ion batteries and lead-acid booster packs.
Lithium-ion jump starters are generally more compact and portable. But don't let their smaller sizes fool you. Portable jump starters can still produce currents strong enough to boost larger diesel engines.
As mentioned above, however, you still need to look for a device that's rated for the engine size of your diesel vehicle. That’s key!
On the other hand, jump starters with lead-acid batteries are heavier, bulkier, and more challenging to store. These are older types of jump-starting tech, which aren’t as popular today.
However, they are generally more reliable, especially in colder weather conditions or when multiple vehicles need to be boosted.
Cable Thickness and Clamp Quality For Heavy-Duty Use
For heavy-duty usage, you'll also want to look for jump starters that are designed to take a beating. Devices with thicker cables and bigger clamps are more durable.
But they also help with high current energy transfer, which is precisely what you need when boosting larger diesel engines and heavy machinery.
Smaller, cheaper jump starters and other car-specific jump starters may work once or twice. But they won't likely last as long, and some may not even be strong enough to boost your vehicle.
Diesel Jump Starter Safety Features
Modern jump starters also come in different sizes and feature configurations, which include things like reverse polarity protection, overload protection, and spark-proof clamps.
These features are particularly important when dealing with larger engines and higher-voltage diesel systems.
On the other hand, you may also find jump starters with additional features, such as LED lights or built-in power banks, that let your device double as a portable power station for charging cell phones, laptops, and other small devices.
Pro Tip - You'll also see jump starters with air compressors, which can come in handy. However, after evaluating dozens these devices and based on our personal experience, we've found combo units just don't make the cut. The vibration from the air compressor tends to cause extra wear and tear on the jump starter components, shortening their lifespan.
Best Portable Jump Starters for Diesel Engines
We generally recommend looking for lithium-jump-starters. But depending on how you intend to use your device, you may want to consider a lead-acid boost pack instead.
Ultimately, what we can’t stress enough is that choosing the best diesel jump starter depends on the size and draw requirements of your engine, as well as how and where you plan to use the device.
Lithium-ion jump starters, as mentioned, are usually lighter and more compact, which makes them more portable and easier to store. They also usually have fast-charging compatibility and USB charging ports, which means keeping them charged up can be more convenient
However, lithium batteries are more sensitive to extreme cold.
So if you'll be jump-starting your diesel in the middle of winter or boosting multiple vehicles in the cold, there's a good chance your device's built-in battery will die before you get the job done.
If that’s the case, you may want to look for a high-quality lead-acid battery booster pack instead.
Recommended Amp Ratings by Diesel Engine Size
We actually have another article that's dedicated to finding the right size jump starter for your specific vehicle.
You can read it here: How Many Amps Do You Need In A Jump Starter?
However, here's a quick overview of which jump starter size to choose based on your diesel vehicle size.
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Small, Light-Duty Diesel Engines (Up to 3.0L) - 1,000–1,500 peak amps.
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Mid-Size Diesel Trucks (3.0L–6.0L) - 1,500–2,500 peak amps.
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Heavy-Duty Diesel (6.6L, 6.7L, 7.3L+) - 2,500–4,000+ peak amps
Pro Tip - Wondering how long it takes to jump start a car or diesel vehicle? With jumper cables, boosting a dead battery can take anywhere between 5 to 15 minutes, or longer if you need to wait for help. However, with a jump box, you can boost a dead battery in minutes, even if there's nobody around to help.
Common Mistakes When Buying a Diesel Jump Starter
Power output (peak amps and cold cranking amps) is the most important decision-making factor when shopping for jump starters.
However, there are some common mistakes that are easily avoidable, such as:
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Buying based on price only - Prices are important. Maybe you can't afford a top-rated jump starter. But generally, higher-priced devices are more reliable and last longer than budget buys.
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Ignoring peak amp ratings - It's crucial to understand the difference between peak amperage and cold cranking amps to make sure you're buying a jump starter that's powerful enough to boost your vehicle's diesel engine.
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Choosing gas-engine-only units - Some jump starters are marketed only for gas engines. Make sure to look for a unit that's specifically designed for larger vehicles, diesel engines, or heavy-duty use.
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Storing in extreme cold without maintenance - Jump starter storage and maintenance are simple. Keep your device stored in a dry location, avoid extreme temperature swings, and always keep the device charged.
How to Use a Jump Starter Safely on a Diesel Truck
Using a jump starter on a diesel vehicle or heavy machinery is just like using one to boost a smaller car.
We actually outline how to use a jump starter in a separate blog post that you can read here: How To Use A Jump Starter.
Here's a quick rundown on how to use a jump starter to safely boost your diesel engine.
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Turn the vehicle's ignition and all accessories off
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Connect the jump starter clamps correctly to the battery
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Turn the device on and make sure you don’t get any warning signals
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Wait a couple of minutes, which allows the glow plugs to cycle before cranking the engines
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Try to start the vehicle, but don’t crank continuously for long durations, which can drain your jump starter fast
If the vehicle doesn't start...
Turn the key off and check your device and connections. Then, try again.
Sometimes it takes a few attempts to get the fuel moving through your lines before the engine starts.
However, if after multiple attempts, the vehicle still doesn't start, you may have an issue with your batteries or other parts of your vehicle.
If the vehicle starts...
Once the vehicle is started, you can disconnect your clamps in reverse order, then allow the vehicle to idle for 10-20 minutes.
This allows the engine and diesel fuel to warm up. But it also gives the alternator some time to recharge the battery.
After that, you should be able to safely turn off the vehicle and put your jump starter away. Just don't forget to recharge your jump starter after use to ensure it's fully-charged ready for next time!
Pro Tip - During winter, if you live anywhere that gets extreme cold, keep your vehicle plugged in. Most vehicles built and sold in North America have built-in engine block heaters, which help keep your battery charged up and the engine warm enough to start, even on frigid mornings.
Final Verdict: What’s the Best Jump Starter for Diesel Engine Dead Batteries?
In the end, the best jump starters for diesel engines depend on how much power your car or truck demands.
Heavy-duty diesel owners should look for high-amp lithium units or lead-acid jump starters like Schumacher or Everstart. You can also look for an industrial-rated booster pack to ensure reliable starts in cold weather and under heavy load.
If you’re on a budget, you can look for lower-priced jump starters at stores like Walmart or Costco. But it's important to look for a model with adequate peak and cold cranking amps for your vehicle.
For most diesel owners, the best overall choice is a premium lithium unit rated to produce at least 2,000+ peak amps.
These types of jump starters should strike an ideal balance between power and portability, making them dependable battery jump starters for larger diesel engines at any time of year.
FAQ Section - Diesel Truck & Car Battery Jump Starters
Here's a quick overview of the most frequently asked questions we hear from our readers about the best jump boxes for diesel engines.
What size jump starter do I need for a diesel engine?
We recommend looking for a jump starter that outputs at least 1,500 peak amps if you intend to use it on a diesel engine. Smaller devices, like JUMPFORCE PRO, may work with light-duty diesel engines, particularly in diesel-powered cars, but not with larger trucks or heavy machinery.
Are portable jump starters powerful enough for diesel trucks?
Some are. Some aren't. It depends on the peak amperage and cold cranking amps the device delivers, not just its size or portability. Some smaller, more portable jump starters produce enough power to boost a diesel truck.
Can a 1,000-amp jump starter start a diesel?
Yes, a 1,000-amp jump start can boost smaller diesel engines, typically up to 3.0L or 4.0L. However, for larger diesel trucks, heavy machinery, or jump-starting in colder weather, you'll want to look for a jump starter that delivers 1,500-2,000 amps.
What is the best jump starter for a 6.7L diesel?
For 6.7L diesel engines, it's important to look for jump starters that deliver at least 2,000 peak amps and are designed to handle dual-battery systems. Make sure to look for NOCO jump starters and other reputable heavy-duty jump starter brands.
How many peak amps does a diesel truck need?
Diesel trucks generally need between 1,500 and 3,000 peak amps. However, it really depends on the vehicle's overall size and class. Smaller, light-duty diesel trucks may start with a 1,000-amp jump starter, but larger, heavy-duty engines may require 3,000 to 4,000 peak amps to start, especially in cold weather.