We’ve been putting on quite a few test drive miles in combined city/highway driving mode. The improvement with the new motor has been astounding! It now has the power to completely move the vehicle down level grades at 50+ mph (i.e. the gas engine idles while the electric motor does all the hard work). This has allowed us to see results of over 40 mpg as verified by both actual gas consumption and the onboard fuel efficiency gauge. We’ve found that the onboard gauge generally registers a bit higher fuel efficiency than reality in gas-mode only and shows a low reading with the hybrid system active.

The current supply chain issues have presented some challenges in getting parts we need. We ordered a custom, more powerful motor almost 6 months ago and it finally arrived. With the machining of a modified axle bracket, it’s now installed. The anticipation is that this motor will be able to fully power the vehicle while driving at speeds of 50+ mph. The previous motor wasn’t able to get all the way there – the gas engine had to provide some level of assist. This previous system topped out at about 30 mpg for combined city/highway driving. It remains to be seen just how much better this motor allows the system to get in terms of fuel efficiency.

The new system which includes many of the latest improvements is ready for installation. The following pictures show the process.

Several of the new pieces are coming together. Some pictures to show the progress:

One of the key pieces in the Unleash system is the throttle interceptor. This device intercepts the connection from the onboard vehicle computer (powertrain control module or PCM) and the throttle pedal. It needs to intercept this so that the electric assist can be given priority over gas operation. There are several ways the electric assist can be proportioned, but the way our system is usually set up to operation is to have the first 0-10% of the throttle movement command 0-100% of the electric system and the remaining 11-100% of pedal travel to command 0-100% of the gas system. This way, when you’re cruising down the road at 50 mph and the pedal might be at 8% (for example), the electric motor is doing all the work moving the vehicle down the road and the gas engine is simply idling.

There is a cable that connects to the vehicle high speed CAN bus to get several important pieces of information such as shift selector position, rpm, and vehicle speed. It also is able to relay to the throttle interceptor information about button presses in the vehicle which allows us to use the volume control buttons on the steering wheel to adjust the electric assist level (when the radio is off). Feedback can be provided by a speaker on the throttle interceptor that can make various sounds/pitches.

Here’s a view of the latest revision of throttle interceptor. Normally, the unit would have epoxy potting compound covering the circuitry. But this view shows the various components. This device mounts under the dash just above the throttle pedal. It uses cable assemblies that use stock vehicle connectors so no modification is required to the vehicle wiring making it easy to both install and remove and eliminating the chance for installer error.

Another important piece of the system is what we call the alternator interceptor. This device intercepts the connection going from the PCM to the alternator. It has another CAN bus connector that ties into the Unleash system. The alternator interceptor’s job is to trick the onboard computer into thinking that the alternator is functioning correctly when the Unleash system takes over powering of the 12 volt system. The alternator interceptor sends the correct signals to the alternator to shut if off when this is taking place. This is one of the nifty ways that the Unleash system is able to maximize fuel efficiency by removing every possible load from the internal combustion engine (ICE).

Just a quick update to show the new active BMS boards as well as the battery module heating boards. The heating serves two purposes. Of course, one of those is to heat the modules in really cold weather. Performance is affected when temperatures drop substantially. With the vehicle usually plugged in, it’s easy and effective to provide some amount of heating to counteract the performance degradation effects. These customized heater boards are able to provide about 120 W of heating. The other purpose though is to aid in high-power balancing of the battery cells. There is a string of heating elements (power resistors) that is switched on to an individual battery cell. This is our own patent-pending technology that serves the purpose of both heating and high-power cell balancing. Our custom active balancing boards have cell-by-cell active balancing. But in addition, there is this additional ~20 W per cell for passive balancing. Typical passive balancing systems are not even a couple watts. This combined active/passive balancing system allows us to very aggressively perform a patented technology that we license which gives a substantial improvement in battery pack life.

A 12 volt monitoring circuit was recently added as a feature to the system. The power pack has four high power 12 volt connectors. These are for:

  1. Connection to the vehicle 12 volt system at the battery
  2. Connection to the power pack’s DC-DC converter that provides power to the 12 volt system from the high voltage battery pack to alleviate the need for power to come from the alternator while the battery pack has a charge
  3. Accessories that run on 12 volts like a high power inverter. This one is intended for on-board devices although it can also be routed to external 12 volt loads.
  4. Offboard 12 volt loads such as a RV.

However, the power pack needs to be able to monitor the 12 volt system so external loads (like an inverter or RV) cannot drain the truck’s 12 volt battery once the high voltage power pack has been fully discharged.

So today was a machining day for the new prototype bus bars. Also, since some modifications needed to be done to the baseplate, it was a good opportunity to throw an Unleash logo on the underside!

With things learned from the initial prototype, work has progressed on several improvements/revisions. Two of the important pieces of the system are the power pack controller and the battery management system active balancing boards. With the schematic and PCB designs completed, they were then fabricated. Next up will be testing.

Hi everyone,

I’ve been designing and building electric vehicle systems since 2004, before there was any hype about EVs – when you couldn’t buy one, so you had to build them. In 2015, I started a project adding a high power electric assist system to a 3-series BMW. I had it operating, and ran into a guy that is now a good friend. He said I should make a system for the F-150, seeing as it’s the most sold vehicle in the US.

And then Lightning Struck.

So I became the proud owner of a 2017 3.5L Ecoboost and began its transformation to a hybridized system with a battery pack, electric motor, and DC-DC converter (which takes the high voltage battery pack and steps it down to the 12 volt system to eliminate the loading that the alternator puts on the engine which both increases fuel burn and decreases power to the wheels). We call it Unleash Energy to highlight how it is bringing more energy to the system and allowing the gas engine to become free from some of the loads it has on it (like running the 12 volt system) so it can deliver all its power to the road.

 

 

Just this week, we were able to demonstrate the full system operation on-road. Here are some pictures:

 

 

The motor sits above the rear differential and is belted to a pulley that sits between the driveshaft and the pinion shaft. No modification is needed to the driveshaft and all pieces bolt on without any drilling, welding, or other modifications to the stock vehicle.

 

 

 

Rear view showing the battery pack in place of the spare tire (sorry spare tire, but the battery pack is better). No other functional space is used and the payload hit is under 100 lbs.

 

 

 

 

Rear view showing the motor sitting above the differential.

 

 

 

The system is very subtle with only the bottom section of the battery pack visible and the charging port just below the bumper.

 

 

 

The battery pack just before installation. It bolts to the trailer hitch and tucks up in the same space the spare tire resided in. Complete installation can be done in 1-2 hours. Removing the system pets the truck back in stock condition.

 

 

Preliminary fuel efficiency improvement has been about 60% (around 17 mpg city driving to about 27 mpg). There are still a lot of tweaks being done, so we’re optimistic we’ll be able to break into the 30’s. Not only is fuel efficiency improved, but power is added to the system. Right now, that’s about 10 HP. With some of the planned mods, that could go as high as about 30 HP.

The default mode of operation is to have the electric system provide as much assist as it can all the time until the battery is spent. This takes some 50-60 miles to do. The mode of operation can be changed so that the electric assist is proportioned out over a longer period. This is ideal for longer commutes. Two methods are being used to switch between assist levels: 1) a smart phone app and 2) vehicle buttons. With the radio off I have the vehicle indicate the button presses on the volume up/down buttons and can use those to change between assist levels. The next version of throttle interceptor will have audible feedback to indicate how aggressive the assist is.

The DC-DC converter is able to provide all of the electric power from the high voltage battery pack. The gas engine no longer has to provide this power and that frees up some excess. This power (up to several HP) can now be directed to the wheels or simply reduce the amount of fuel that is burned.

We’ll continue to see how power and fuel efficiency are improved and will post updates as we go. Still several things to enhance and features to add, but it’s been an exciting week to finally get it on the road and start getting the data.