My first impression is the privately made batteries by Hybrids Plus are larger in capacity than the Ford ones. Ford's is said to be a "30 mile" pack. Hybrid's Plus designed their battery to be about a 35 mile pack on paper, but not knowing how good the FEH really was, over-shot their goal, and ended up with a 50 mile pack, that was in almost the same size package as the original. ( it was about 1" taller than the stock one... hardly noticeable under the carpet )

That's 50 miles in "blended mode" not pure EV. But that equals 50 miles at 140 MPG! You see, Hybrids Plus wants all their cars to be "street legal". That requires the engine and exhaust systems to stay hot, just like your car does now.

Hybrids Plus used battery cells that did not need cooling, thus battery cells were added into all the nooks and crannies that used to have cooling fans. I don't know about Ford's, but if they still have cooling fans, that may account for the fact they have made a pack with less capacity: the fans would take up space. ( don't know, just guessing ) I used the Hybrids Plus battery for 5 hours on a warm day, and the pack never got more than 1 or 2 degrees above ambient air in the car. That was amazing.

It's all in the programming, and not much "hack" was required really. In both versions, the pack does most of the work. I took the prototype up a steep grade at highway speed ( 50 miles per hour ) and never exceeded 1800 RPM.

On flat highway at 58 miles per hour I was getting 90 MPG.
Stop and go in the city, using P&G I was getting 141 MPG.

Ford's sounds very close to that kind of performace, with maybe 25% less range.

Cost for Hybrid's Plus to make them one at a time is about $35k.
Cost to produce the packs in larger (1000) quantities would be about $25k.

With Ford's slightly smaller size, and mass-production (100,000) capabilities, price of this kind of pack may be about $15k at today's prices.

How many people would buy a plug-in FEH with 30 miles of "boost" for $45,000? I'm on the fence with this senario....
( still can't get one from Ford... just a "what if" )
You can get one custom made for you car for $35,000 on top of the price of your FEH... ( $65,000 car ) TODAY! ( well, they need 2 weeks notice )

-John