FAQs 2017-06-06T11:32:01+00:00


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Suitable vehicles and route types

What types of vehicles are suitable for hybridization with a Lightning Systems LightningHybrid?

Lightning Systems’ LightningHybrid is designed for medium and heavy duty vehicles with a front engine and a drive shaft which runs from the transmission to the rear differential. This makes it suitable for many classes of trucks, vans and buses, but not applicable to passenger cars.

Do engine type or fuel matter?

The LightningHybrid will work with standard gasoline and diesel engines; and also with engines running on compressed natural gas, liquid natural gas, biodiesel, etc. The system operates between the vehicle’s transmission and the wheels, with no modifications to the engine or transmission.

What are the best route types for a hybrid vehicle?

A regenerative braking hybrid, such as the LightningHybrid, operates by storing energy during braking and redeploying it during subsequent acceleration. This means that its benefits are best seen on vehicles which stop and start frequently such as urban delivery vehicles, shuttle buses, trash/refuse haulers, logistics vehicles, etc. Vehicles in locations with heavy traffic on highways will also benefit due to frequent deceleration and acceleration.

Is there a list of supported vehicles?

A current list of supported OEMs and vehicle models can be found on our website. Additional vehicles can be supported depending on suitability of the chassis, and the expected number of units. Please contact us for more information.

How the hybrid system works

What is a hybrid vehicle?

A hybrid vehicle is one which blends two propulsion systems to provide benefits which can include improved fuel economy, emissions reductions, and others. In the case of a vehicle equipped with a Lightning Systems LightningHybrid, the two propulsion systems are the vehicle’s internal combustion engine and a hydraulic motor which applies torque (turning force) to the drive shaft.

What is regenerative braking?

A regenerative braking system slows the vehicle by converting motion (kinetic energy) to a form of energy that can be stored and then reapplied by assisting the vehicle to accelerate.


How does the hydraulic hybrid system accelerate the vehicle?

When the driver presses the accelerator pedal, pressurized hydraulic fluid is released from an accumulator (a high pressure tank with a nitrogen-filled bladder inside) and passes through a hydraulic motor. This applies torque to the vehicle’s drive shaft, which reduces the work the engine needs to do to accelerate the vehicle. The engine consumes less fuel and produces fewer emissions.

How does the Lightning Systems' hydraulic hybrid system slow the vehicle?

When the driver presses the brake pedal a clutch engages the hydraulic motor, which operates as a pump, forcing hydraulic fluid into the accumulator. This fluid compresses the bladder, causing the pressure to rise, which stores energy, similar to compressing a spring. The pump puts drag on the drive shaft, which decelerates the vehicle. The vehicle’s kinetic energy is converted to stored hydraulic pressure.

What happens when the accumulator becomes fully charged?

During a prolonged braking event, such as down a hill, the accumulator may become fully charged, which means that the pressure has reached the maximum operating level. At this point, the system will enter “bypass mode”. This allows the driver to continue to employ hybrid braking with minimal change in brake rate or feel. In this way, the system is operating in a manner much like that of the common brake retarder found on many heavy duty vehicles.

What happens when the accumulator becomes fully discharged?

After assisting the vehicle to accelerate, the accumulator will become discharged, meaning that all the fluid has left it. At this point, the system’s clutch disengages, and the vehicle operates as a standard vehicle using the internal combustion engine until the next time the brakes are applied.

Is the LS system a 'parallel hybrid' or a 'series hybrid', and what does that mean?

The LS LightningHybrid is a parallel hybrid. This means that it operates independently of the OEM engine and transmission, only applying torque to the drive shaft. Typically, a parallel hybrid system does not apply any modifications or tuning to the engine, transmission or other OEM components; and is easy to install as an after-market (retrofit) component. Unlike series hybrid systems, if a parallel hybrid system fails, the vehicle remains operational as a conventional vehicle. A parallel hybrid system can be offered on a wide range of vehicles, with new vehicles added relatively easily.

A series hybrid system is designed to have a much tighter integration with the OEM systems than a parallel hybrid. A series hybrid may deliver better fuel savings. Series hybrid systems are usually not retrofittable and are designed specifically for each vehicle.

What are the main technological advances embodied in the LS LightningHybrid?

The industry-leading performance of the LightningHybrid is enabled by three technological innovations:

  • Carbon-fiber composite high pressure accumulators providing a lightweight hydraulic vessel (or tank) for energy storage;
  • High speed embedded digital controllers, running sophisticated proprietary software which delivers drivability, reliability, fuel savings and emissions reductions;
  • Modular design ensures applicability to a wide variety of vehicle platforms.

LightningHybrid labeled

The main components of the LightningHybrid.

Fuel savings

How does the hybrid system save fuel?

The LightningHybrid applies torque (turning force) to the vehicle’s drive shaft during acceleration from a stand-still or low speed. This reduces the load on the engine, which means that the engine draws less fuel. Imagine starting a vehicle on a downward slope – the engine does not work as hard. The same is true when the LightningHybrid assists acceleration using energy captured during the previous braking event.

How much fuel is saved?

Lightning Systems’ customers typically report 15% to 35% fuel savings.

The amount of fuel saved will depend strongly on how much acceleration and deceleration is experienced during a typical drive cycle. Urban deliveries, shuttle buses, refuse haulers and the like will see strong savings; vehicles primarily used on the highway will see less. Other factors can influence the results, such as amount of time spent idling.

Brake Savings

How are the existing vehicle brakes coordinated with the LH system?

The LightningHybrid monitors brake pedal position to allow the system to do some or all of the braking, blending with the vehicle’s standard brakes. The LightningHybrid detects conditions such as an emergency stop, in which case the friction brakes function as normal (including ABS if applicable).

Will the vehicle’s brakes see less wear?

Yes. Since most of the braking is done by the hybrid system, the vehicle’s wheel brakes will see much less wear, often being used only to hold the vehicle stationary, or for emergency stops. Brake components may last four to eight times longer than on a non-hybridized vehicle.

Is the engine shut down while braking?

Lightning Systems does not shut down the engine during braking. All auxiliary systems work as in their non-hybrid counterparts. The Lightning Systems LightningHybrid can also be easily integrated with most anti-idling technologies.

On some vehicles, the LightningHybrid has a “Park Idle Shut-Off” feature, which shuts off the engine at some interval after the vehicle is placed in “Park”. This is covered in more detail in the next section.

Environmental benefits

What are the main types of vehicle emissions?

Internal combustion engines emit harmful gases which fall broadly into two categories: greenhouse gases and gases which degrade air quality. Two significant gases which are regulated by governments are CO2 (a greenhouse gas) and NOX (a combination of NO2 and NO), which is a primary component of smog. In addition, Particulate Matter (PM) consists of microscopic solid particles such as soot, which can be inhaled, causing respiratory problems.

Vehicles also generate PM from brakes and tires. These particles can be significantly toxic.

What is the effect of the LightningHybrid on vehicle emissions?

  • CO2 emissions are reduced by approximately the same amount as fuel consumption, which is typically 15% to 35%.
  • NOX emissions can be reduced by 50%, as verified by third-party testing.
  • PM from the vehicle’s exhaust is also reduced, though a working PM filtration system will handle most of the soot.
  • PM from brake wear (brake dust) is dramatically reduced by the LightningHybrid as most braking is performed by the hybrid system.

What are cities doing to improve air quality and reduce global warming?

Some of the world’s most polluted cities (e.g. Mexico City, Delhi, London, Paris) have imposed strict driving restrictions and fines on medium and heavy duty vehicles. These restrictions may be waived or reduced for hybrid vehicles, like those running the LightningHybrid.

How have recent revelations about car manufacturers cheating emissions tests affected Lightning Systems?

The recent publicity concerning emissions crimes by certain car manufacturers has increased the public’s awareness of automotive NOX emissions, which strengthens the case for clean air solutions such as the LightningHybrid. It has put a bigger spotlight on emissions testing, especially how lab tests compare to Real Driving Emissions (RDE). LS’s emissions tests are run and verified by the Colorado State University Engines and Energy Conversion Lab, SGS Testing (an EPA certified vehicle testing facility), and other testing groups. In addition, RDE are measured using PEMS (Portable Emissions Measurement System) to verify that the LightningHybrid reduces emissions for real on-road driving situations, confirming that emissions savings are not only seen in standardized testing.


Is the LightningHybrid safe?

The LightningHybrid stores energy by pressurizing nitrogen gas and hydraulic fluid to high pressure in the High Pressure Accumulator. This component has been designed to withstand pressures that are more than 300% of the LightningHybrid’s maximum operating pressure, so the risk of failure is extremely low. The accumulator’s design ensures that in the rare case of a failure, it will fail by leaking and not by exploding. In the case of intense heat, such as a vehicle fire, the accumulator is designed to release its contents by venting, avoiding the risk of explosion. It is also protected from impacts from, say, road debris.

The hydraulic fluid used in the LightningHybrid has a relatively high flash point, which means that in the case of a fire it is less likely that the fluid will ignite than, say, gasoline or CNG. Nitrogen gas is inflammable and poses no fire hazard.

What happens when the LightningHybrid leaks?

Lightning Systems ensures that no leaks are occurring when the system is commissioned for road use. However, wear and tear may result in a slow leak occurring, so fleets should follow Lightning Systems’ recommended inspection schedule to check the LightningHybrid for leaks or other damage. A small leak does not immediately impact LightningHybrid operation, but should be addressed as soon as possible.

In the case of a major fluid leak, the LightningHybrid will automatically stop operating but the vehicle remains driveable. However, a repair should be scheduled as soon as possible. For clean-up at the leak site, follow procedures for cleaning up automatic transmission fluid.

Driving a hybridized vehicle

Is the system fully automatic? If not, how does the driver control it?

The LightningHybrid drive system is designed to be as transparent to the operator as possible. The user simply turns the key and drives the vehicle as he/she normally would with the brake and accelerator pedals. Other than the sound of the hydraulic motor(s) in operation during braking, the only noticeable difference to the driver is an improvement in 0-30mph acceleration, and an enhanced braking performance that reduces stopping distance.

What feedback does the driver get?

Some vehicles equipped with a LightningHybrid system are equipped with a green on/off light on the dashboard. The illuminated state indicates that the hybrid system is operating normally. If a fault occurs, the light will go out.

Some vehicles are equipped with a Driver Information Display which shows the current status of the LightningHybrid, including operating mode and level of charge in the accumulator. Drivers can learn to use this display to help them to maximize fuel savings. This display also shows warnings and error conditions if they arise.


How does the LightningHybrid handle adverse braking conditions, such as braking on slippery or loose surfaces?

Under most driving conditions, the system’s hydraulic braking and acceleration perform in a predictable and easily controllable fashion. In the event of extremely poor road conditions, the hybrid system will automatically disengage, allowing the vehicle’s Anti-Lock Braking System (ABS) and traction control system to provide the safest control possible.

Are drivers required to be trained in order to operate the hybridized vehicle?

Training is not a requirement. However, Lightning Systems provides driver training to new customers to help drivers to understand what’s different about the vehicle and how to drive it to get the best fuel economy results. Training materials are also provided so that customers can train new drivers.

Why should drivers minimize the time spent idling?

Idling uses fuel and generates pollution, often needlessly. If a vehicle idles a lot on a route, the benefits of the LightningHybrid are reduced. Lightning Systems therefore encourages and trains drivers to shut off the engine as much as possible when the vehicle is stopped.

Does the LightningHybrid enforce idle shut-off?

On some vehicles, the LightningHybrid has “Park Idle Shut-Off” technology, which shuts off the engine at some interval after the vehicle is placed into “Park”. Pressing the brake pedal restarts the engine. In certain situations, the engine will not shut off, such as when the battery voltage is too low, or the cabin is too hot or cold. Other vehicles may have idle shut-off technologies from other vendors. The LightningHybrid is compatible with these.

Are there any training materials for drivers?

Yes, you can find training videos and other materials on-line at lightningsystems.com/drivers

Changes to a hybridized vehicle

How much does the LightningHybrid weigh?

Because the product scales to suit the gross vehicle weight (GVW) of the target vehicle, the system can weigh between 600 and 1100 lbs (270 to 500 kg).

What is being changed from stock on my vehicle to integrate the LS system?

The LightningHybrid is a parallel hybrid system. It is simply added to the existing drivetrain without modifying any major components. The gearbox (Power Transfer Module), which facilitates the hybrid drive, is installed in place of an OEM U-joint and a shorter drive shaft is installed to complete the installation. The stock brake pedal is removed and a custom one installed, and some wiring is installed for controls and sensors. In some cases, the (post-catalytic converter) exhaust may need modification to accommodate the placement of the system, and occasionally the evaporative emissions (EVAP) canister must be moved.

Hydraulic and engine acceleration are initiated and blended electronically with no modification to the vehicle engine, transmission or emissions systems. Braking is initiated and blended with the aftermarket brake pedal detailed previously.

If the system must be uninstalled, the hybrid drive can be removed and the stock drive shafts re-installed in approximately one hour.

Considerations for fleet operations

Will the system void my original manufacturer's warranty?

The system will not void the manufacturer’s warranty. The system is only designed to replace a portion of the torque normally provided by the engine. It does not exceed the design limits of OEM drivetrain components and therefore the protection provided by the OEM warranty remains in place. In addition, installation is performed in accordance with OEM requirements for vehicle modifications. Lightning Systems has been granted eQVM certification by Ford, which guarantees that Ford’s warranties on the vehicle remain in effect. Finally,because the system does not modify the engine’s control system, government certifications relating to emissions regulations remain valid.

What is Lightning Systems' standard warranty for the system?

Lightning Systems provides a base warranty of 5 years, 60,000 miles. A 5 year, 100,000 mile extended warranty is available.

How reliable is the system? What maintenance is required, and what is the expected lifetime?

The customer should expect reliability to be similar to that of its conventional trucks and buses. The system design utilizes industrial components commonly found in standard heavy equipment like tractors and mining machinery. It is designed to be low maintenance, requiring minimal servicing by the owner. Unlike a battery, hydraulic accumulators and pumps are designed to perform for upwards of 500,000 cycles with routine fluid and bladder replacements. Due to the modular nature of the hybrid drive it can actually outlast the vehicle itself and be transferred to another fleet asset of similar make/model.

What happens in the case of LightningHybrid malfunction?

Should the hybrid system malfunction, its clutch will automatically disengage, allowing the vehicle to continue operation as a conventional vehicle. This enables the fleet manager to schedule routine and unexpected maintenance for off-shift hours, further increasing asset availability rates.


What's involved in installing an LS hybrid system into a vehicle?

The LightningHybrid‘s parallel architecture makes installation relatively simple. Installation consists primarily of the following steps:

  • Raise the vehicle on a lift and remove the drive shaft between the transmission and the rear differential.
  • Raise the hybrid system to the vehicle and bolt it between the chassis frame rails. Install new sections of drive shaft which connect the vehicle’s transmission to the hybrid system’s power transfer module, and the power transfer module to the vehicle’s rear differential.
  • The vehicle’s exhaust system (dowstream of the catalytic converter) may need to be rerouted to accommodate the hybrid system.
  • Install electrical cabling for power, sensors, brake pedal connections, on/off switch, etc.
  • Depending on how the hybrid system was prepared before shipping, it may be necessary to pressurize the system with nitrogen gas and hydraulic fluid.
  • Test/commission the vehicle to verify operation and optimize operational parameters.

Who performs the installations, and where?

Installation can take place at a variety of locations: OEM facilities, dedicated installation partners, or dealers who provide installations, service and maintenance. Lightning Systems continually engages new partners, and will connect you to the partners who can best serve you. In some cases, Lightning Systems will perform installations at our Loveland, Colorado, facility. Additionally, if a fleet operator has a suitable facility, installations can be performed on-site.

Installation and commissioning a vehicle may take as little as one day to complete.


Does the LightningHybrid generate data?

Yes. The LightningHybrid monitors every operational parameter once per second, including accumulator pressure, fluid temperature, brake and gas pedal positions and many others. It also records any warnings or errors generated in the system. This data is uploaded to Lightning Systems via a wireless modem, allowing us to calculate the vehicle’s fuel savings, as well as identifying good or less good driving practices. And if a problem occurs, we can identify it quickly and resolve.

Can the fleet access the telematics data?

Yes. Lightning Systems offers customizable services to fleets seeking to understand and utilize the data coming from their hybridized vehicles, including a web-accessible dashboard showing fuel economy, driving habits and other metrics.

Comparison with electric hybrids

What are the main differences between electric and hydraulic hybrids?

Although electric hybrids are well proven, electric hybrid technology is limited in several ways:

Cost: The cost of second generation batteries that can charge faster, go farther, and last longer is currently prohibitively expensive, ranging from $10,000 to over $40,000. Equivalent hydraulic accumulators cost approximately $5,000, and they last longer.

Energy capture rate: The time taken to capture – and release – energy not only impacts overall efficiency and utilization, but also how efficient the brake regeneration system is. A typical electric brake regeneration system may deliver 21% efficiency, while hydraulic brake energy regeneration efficiency is over 70%, since hydraulics are not limited by battery charging rates during the regeneration cycle.


Battery Weight: Weight has a dramatic impact on overall transportation efficiency, and even lithium ion battery technologies add significant weight, ranging from 350 to well over 1,000 pounds. Equivalent storage in carbon fiber tanks weighs 200 pounds. This problem becomes extreme for medium and heavy duty vehicles.

Maintenance talent availability: Electric hybrid vehicles are highly complex and the DC power can be dangerous if not handled by specifically trained mechanics. There are not a large number of specifically trained mechanics in the US today, and the training requirements are significant. Most fleet mechanics already have training and a strong comfort level with hydraulic technology.

Fire hazard: The batteries in electric hybrid vehicles can cause vehicle fires, however hydraulic fluid has a high flashpoint and nitrogen is inert making the hydraulic hybrid safe and reliable.

Financial Questions

What is the price range for an LS system?

The LightningHybrid represents low capital cost for fleets. The price of the LightningHybrid depends on various factors, such as vehicle GVW and the number of units. It includes installation and training.

What is the typical ROI?

Financial ROI is dependent on many factors, some of which show significant variability:

  • Fuel price – the higher the price of fuel, the shorter the ROI term.
  • Drive cycle – frequency of stopping and starting, time spent idling, amount of highway driving, and so on, affect the efficiency, and therefore the ROI of the system.
  • The base fuel efficiency of the vehicle – the lower the miles per gallon, the shorter the ROI term.
  • The price of the hybrid system – this varies, as stated above, by vehicle weight and the number of units ordered.

A typical ROI term generally is less than half of the life span of the vehicle. In places where grants or incentives are available it is much shorter. In addition, the LS system can be financed to provide most fleets an ROI in the first month based on lease rates.

Lightning Systems has an app and an online calculator to assist with ROI evaluation on a case by case basis. Please speak with your sales representative.

How does the LightningHybrid affect my vehicle total cost of ownership?

Reduced fuel use and reduced engine load will lead to vehicles having a longer engine life, and since the LightningHybrid performs much of the braking function the vehicles brakes will last up to eight times longer. In addition, vehicles will spend more time working and less time fueling and in the shop changing brakes. Fuel savings, potential carbon credits and opportunities for marketing your green vehicles also contribute to business advantages.

How do emissions savings improve my ROI?

By reducing emissions using the LightningHybrid, fleets will be able to tell their customers that they are keeping the air clean in the communities where they operate. This positive marketing approach has been used with great success around the world by a variety of companies. In addition, most grants and vouchers are tied to emissions reductions. These programs can cover the cost of the LightningHybrid up to 80%, thereby greatly improving the ROI.

Are there grant and tax incentives available for the LS system?

Yes. The LS system qualifies for a variety of grants and incentives at the local and national levels. Lightning Systems can assist you in finding and applying for funding when appropriate. Please speak with your sales representative.

What financing options are available?

Lightning Systems offers financing options including lease, rental and third party financing. Please speak with your sales representative.

Where can I get further information?

You can always contact Lightning Systems with questions or to discuss how the LightningHybrid would work for you.

You can find a map of our current dealer locations here: