FAQ

A; With over 15 years of expertise in solar energy, energy storage, and emergency generators, Fortified Energy Systems is at the forefront of developing innovative energy solutions. Our flagship product, the epu™ , was created using cutting-edge technology refined through years of research and development. Powered by high-capacity lithium batteries, the epu™ provides uninterrupted energy to cabin comfort devices like heating systems, air conditioning, lighting, and other electronic equipment, creating a serene and comfortable environment for drivers on the road.Our experience spans large-scale solar and microgrid systems, as well as the development of new energy products designed to benefit people and the planet. At Fortified Energy Systems, we are committed to advancing the green future through reliable and sustainable energy solutions.

No, you only need one epu™ model per truck. The two models—Mark One and Cabin Comfort—are designed to meet different needs, but both provide the same reliable performance. • The Mark One is an external unit mounted on the back of the truck’s cabin. • The Cabin Comfort is a compact, smaller unit mounted inside the truck’s cabin under the sleeping berth. For truckers hauling in extreme hot or cold climates, the Cabin Comfort is an ideal choice. It complements the truck’s existing air conditioning or heating system. For example, when you’re on the road, you set the truck’s AC or heater to your preferred temperature. Once parked, the Cabin Comfort can adjust the temperature up or down by up to 28°F (15.5°C) and maintain it for up to 12 hours—providing a consistent and comfortable environment inside the cabin. Choose the model that best fits your needs—one device is all you need for ultimate comfort and efficiency!


The epu™ (Environmental Power Unit) is a stand-alone power system designed for trucks that provides up to 12 hours of continuous power without needing to connect to the truck’s engine or alternator. It runs independently, using advanced lithium batteries to power heating, air conditioning, lighting, and other cabin devices, ensuring comfort without idling.

The epu™ comes in two different models to suit your needs: Mark One: An external unit mounted on the back of the truck’s cabin, ideal for those who prefer an outside installation. Cabin Comfort: A compact, smaller unit installed inside the cabin under the sleeping berth, perfect for truckers who value space efficiency and a quieter, vibration-free environment. Both models offer the same powerful performance and efficiency, allowing you to choose the one that best fits your lifestyle and trucking needs.


The epu™ saves up to 1 gallon of diesel per hour when the truck is on idle, leading to annual fuel savings of approximately $19,000. By minimizing idling, the epu™ also reduces engine wear and maintenance costs, further enhancing overall savings. Please click here to use our saving calculator.


Yes, the epu™ is designed to be completely maintenance-free. There are no moving parts, no combustion engine, and no need for regular water refills or filter changes like traditional APUs. It requires as much maintenance as any other electronic device, such as a TV or computer, making it a hassle-free solution for long-term use.

The epu™ transforms the truck cabin into a quiet and comfortable space. It maintains stable temperatures—cooling up to 26 degrees below or heating up to 24 degrees above the outside temperature—without the noise and vibration of a running engine. Additionally, it powers its own revolutionary Heating and Air Conditioning System, providing drivers with a restful environment for better sleep and improved alertness.

The epu™ (Environmental Power Unit) is a stand-alone power system designed for trucks that provides up to 12 hours of continuous power without needing to connect to the truck’s engine or alternator. It runs independently, using advanced lithium batteries to power heating, air conditioning, lighting, and other cabin devices, ensuring comfort without idling.

The epu™ helps reduce emissions of harmful pollutants like carbon monoxide, nitrogen oxides, and particulate matter. By reducing idle time, it cuts carbon dioxide emissions by up to 550 pounds per year for every hour of idling reduced, contributing to cleaner air and public health.

Absolutely. The epu™ provides a home-like sleeping environment with no engine noise or vibration and stable cabin temperatures, making it a valuable feature in driver recruitment campaigns. This enhanced comfort can help attract and retain reliable CDL Over The Road drivers.

Yes, various federal and state grant programs support diesel emission reduction technologies like the epu™. These programs can cover between 50% to 100% of the cost, making the epu™ an affordable option for fleets looking to enhance sustainability. For more information, you can check programs like Arkansas's Diesel Emission Reduction program here.

Absolutely. The epu™ provides a home-like sleeping environment with no engine noise or vibration and stable cabin temperatures, making it a valuable feature in driver recruitment campaigns. This enhanced comfort can help attract and retain reliable CDL Over The Road drivers.

The epu™ helps fleets comply with strict state and federal idling regulations, such as California’s rule limiting idling to no more than five minutes, with fines of $300 per violation. It also supports compliance with Department of Transportation (DOT), Environmental Protection Agency (EPA), Federal Motor Carrier Safety Administration (FMCSA), and National Highway Traffic Safety Administration (NHTSA) regulations. By reducing idle time, the epu™ ensures that your fleet meets these requirements, avoiding costly fines and contributing to a cleaner environment. For a detailed overview of idling regulations across different states, you can refer to the Idling Regulations Compendium.

Yes, the epu™ features intelligent management that allows you to monitor and control the unit remotely via a mobile app. You can check battery charge levels, manage energy consumption, and adjust settings from your phone or tablet.

Idling your engine for extended periods can cause significant damage, leading to costly repairs. According to Popular Mechanics, idling can strip oil away from the engine’s pistons and cylinders, causing premature wear and tear. Modern engines are equipped with sensors that regulate fuel consumption, but idling prevents these sensors from functioning correctly because the engine doesn’t warm up sufficiently. As a result, the fuel-to-air ratio remains too rich, causing excess fuel to wash away the lubricating oil that protects critical components like piston rings and cylinder liners. This lack of lubrication accelerates wear and reduces the lifespan of these parts, ultimately increasing maintenance and repair costs. By using the epu™ , you can minimize engine idling, thereby preserving the engine's integrity and reducing expensive repairs.

No, the installation of the epu™ does not void your truck's warranty. Unlike other electrical APU solutions that require connecting to the truck’s alternator or installing an intelligent alternator, which often results in losing the engine warranty, the epu™ operates independently. Our system is self-operating and does not need any connection to the alternator or engine components. The only required connection is to the truck’s battery and switch, allowing the epu™ to recharge its batteries using the energy generated when the truck is in motion. This design ensures your truck’s engine warranty remains intact while providing all the benefits of an efficient power solution.

Absolutely. The epu™ has undergone extensive testing throughout its 6-year development to ensure it delivers outstanding performance in the toughest environments. Engineered with carefully selected materials, advanced technology, and robust design, the epu™ is built to handle real-life challenges—from the hot and humid jungles of South America to the freezing elements of Alaska. Its durability ensures reliable operation in both extreme heat and cold, making it a dependable power solution for all weather conditions.

Definitely. The epu™ is specifically designed to provide powerful cooling and heating performance, making it ideal for extra-large sleeping berths and cabins. It offers 6,100 to 9,100 BTU/hr for cooling and 6,700 to 10,100 BTU/hr for heating, allowing it to maintain temperatures up to 26 degrees below the outside temperature or 24 degrees above for up to 12 hours. With multiple epu™ sizes available, we can meet 99% of market needs. If you have any concerns, please contact us, and we will find the best solution for your specific requirements.

Yes! The epu™ is designed for flexibility and ease of transfer. Each unit is securely attached using brackets, which can be purchased from us for additional vehicles. Once the brackets are installed on another truck, transferring the unit is quick and simple. The Cabin Comfort model, being smaller and lighter, is especially easy to move. You can effortlessly snap it out from one truck and install it in another. Its portability even makes it a great option for use in your RV, allowing you to enjoy its comfort and efficiency while camping on the weekends. Switching between vehicles has never been easier—just install the brackets and take your comfort wherever you go!


The epu™ batteries are recharged while the truck is in motion, using the energy generated by the truck’s engine. To reach full capacity, the batteries need approximately 4.5 hours of driving time. Additionally, there are options to recharge the batteries using a 210V regular power outlet or by utilizing solar panels, which are available as a separate accessory (please contact us for details). These flexible charging options ensure that the epu™ is always ready to provide uninterrupted power whenever you need it.

LiFePO4 (Lithium Iron Phosphate) batteries are a type of lithium-ion battery known for their high safety, long lifespan, and excellent performance under tough conditions. These batteries typically last up to 4,000 charge cycles, translating to about 4+ years of real-life use, depending on the application. Unlike other lithium-ion chemistries, LiFePO4 batteries are thermally stable and less prone to overheating or catching fire, even under extreme temperatures or physical damage. They are incombustible, which makes them ideal for the rigorous demands of trucking environments. LiFePO4 batteries are highly durable and can handle vibrations, shocks, and deep discharges—conditions frequently encountered in the trucking industry. Their lightweight and compact form makes them an excellent fit for trucks, providing reliable energy without adding unnecessary weight. These batteries ensure excellent safety and durability, reducing risks of failure or fire hazards, making them an optimal choice for long-haul trucking

The installation of the epu™ is straightforward and requires two individuals with basic mechanical skills. The installation takes approximately 2-3 hours and involves mounting the unit on the external back side of the truck. We have also established a network of authorized truck shops trained to install the unit quickly and efficiently. These shops typically charge a fee ranging from $800 to $1,200 for installation services. For a list of authorized shops or to find a shop near you, please contact us directly.

As a unique product with no direct competitors on the market, the epu™ is available exclusively through our website. While many of our sales start offline, we also have a dedicated team of knowledgeable field professionals who can meet with you, answer your questions, and address any concerns you may have. Additionally, our product is available through our distribution network, which includes trucking shops and other companies offering trucking services, making it even easier to access the epu™. For more information or to schedule a meeting, please feel free to contact us via email at info@fortifiedenergy.com or by phone at 877-382-2337

Investing in the epu™ is one of the smartest financial decisions you can make for your truck. With fuel savings, reduced maintenance, and fewer repair costs, the epu™ can start putting money back in your pocket almost immediately. Most users see a complete Return on Investment (ROI) in about 9 months. After the first year, you could be saving approximately $19,000 annually, all while enjoying the added comfort of a noise and vibration-free cabin. Built to last up to 5 years with 4,000 battery recharging cycles, the epu™ is designed to deliver long-term value without the hassle of regular maintenance. All this comes with a one-time investment of $15,000, an amount that quickly pays for itself through ongoing savings. Use our online savings calculator to see just how much you stand to gain.

Yes, absolutely! We offer very affordable financing options with ZERO down and manageable monthly payments that allow you to save on fuel even while making your payments—truly a win-win solution!

The application process is easy and convenient and can be completed directly through our website. Get started today and enjoy the benefits of the epu™ without worrying about upfront costs.


Yes, the epu™ comes with a 2-year warranty, providing you with peace of mind and protection against potential defects or issues. To activate your warranty, registration of the unit is required upon arrival to the client. This ensures that you receive full coverage and support throughout the warranty period, guaranteeing the reliability and quality of your epu™ .

To be on the safe side, we estimate a lead time of 3 weeks from the time your order is placed. However, most of our orders are typically ready to ship out from our manufacturing facility within 2 weeks. We partner with UPS for shipping, offering delivery directly to your door or to an authorized truck shop of your choice. The epu™ unit weighs 135 lbs and is securely packed and attached to a pallet to ensure safe transport.

We are committed to ensuring that you are happy with your purchase. If you encounter any issues, please contact us within 30 days of purchase. If we cannot resolve the problem and the unit remains undamaged and in working condition, we will be happy to refund you the full amount, minus the shipping charges in both directions. Your satisfaction is our priority, and we will work with you to make sure your experience with our product is positive.

We have designed our packaging to minimize the risk of damage during shipping, but unforeseen issues can still occur. That’s why we strongly encourage you to inspect the unit upon arrival and take pictures of any visible damage. This documentation will allow us to open a claim with UPS promptly. Our team will work on the claim immediately, ensuring a quick resolution, and we will send you a replacement unit as soon as possible. Your prompt inspection and reporting help us resolve any shipping issues efficiently, ensuring you receive a fully functional product without delay.

We are excited to expand our network of distributors and make the epu™ accessible to more users. Our distributor program is designed to provide attractive profit opportunities for our partners. To get started, we encourage you to contact us directly to discuss eligibility and learn more about the benefits of becoming an epu™ distributor. We look forward to working with you to grow our reach and bring innovative energy solutions to a wider audience.

Yes, we offer a 2-year warranty on the full system, including the batteries. Since the batteries are an integral part of the system, they are fully covered under our 2-year warranty.

No chance. Our batteries are very different from traditional liquid-based batteries. They are high-profile devices, with each cell equivalent to a full truck battery. We have tested them rigorously for 7 years in the jungles of Panama under 98% humidity, as well as in other harsh conditions. This ensures high capacity recharging cycles and reliable performance at full capacity.

No, our engineers have developed a patented and innovative method for producing cool air without using refrigerent R-410A. This unique approach sets our epu™ apart in terms of efficiency and environmental friendliness.

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