Automotive

Tiny briefcase engine boosts EV range beyond battery power

Tiny briefcase engine boosts EV range beyond battery power
It's bigger than the average briefcase, and certainly not "briefcase-shaped" compared to any briefcase we've seen, but the C15 is designed to be small and sleek enough to easily integrate into many EV classes and layouts
It's bigger than the average briefcase, and certainly not "briefcase-shaped" compared to any briefcase we've seen, but the C15 is designed to be small and sleek enough to easily integrate into many EV classes and layouts
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It's bigger than the average briefcase, and certainly not "briefcase-shaped" compared to any briefcase we've seen, but the C15 is designed to be small and sleek enough to easily integrate into many EV classes and layouts
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It's bigger than the average briefcase, and certainly not "briefcase-shaped" compared to any briefcase we've seen, but the C15 is designed to be small and sleek enough to easily integrate into many EV classes and layouts
Horse Powertrain goes the other direction from its electric motor lineup, developing an ICE generator designed to hybridize electric vehicles for more range, less anxiety
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Horse Powertrain goes the other direction from its electric motor lineup, developing an ICE generator designed to hybridize electric vehicles for more range, less anxiety
Horse will show the C15 at next week's IAA Mobility Munich show
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Horse will show the C15 at next week's IAA Mobility Munich show
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Automotive supplier Horse Powertrain continues to push the next generation of plug-and-play range-extended hybrid solutions. Sized "no larger than a briefcase," the all-new C15 four-cylinder engine-generator is designed to slide into all-electric vehicle platforms with little to no modification necessary, bringing an immediate high-efficiency range boost with or without turbo.

Horse has always struck us as a company just over the right side of the thin wire fence dividing genius from insanity. Had it debuted a couple of years earlier, when the automotive world had its head down toward going 110% all-in on electric vehicles, it would have struck us as a bit insane, or at least "too little, too late." But having ramped up at a time when governments and automakers worldwide are rethinking those EV plans and timelines, it seems to be perfectly positioned for a renaissance in hybrid technology. For now, at least.

Regardless of what anyone else thinks, though, Horse remains convinced that the future of electrified vehicles is hybrid, and it continues expanding its lineup of range extender solutions engineered to support that future. At the start of the year, it began production on a compact electric motor meant to fit to ICE-powered vehicles for improved efficiency and emissions performance. Now it presents something of an opposite counterpart: an ultra-compact ICE designed to slide into all-electric models to boost range and add refueling capability to complement battery charging.

One way or another, Horse wants automakers to find just the right balance of electric and combustion drive power.

Horse Powertrain goes the other direction from its electric motor lineup, developing an ICE generator designed to hybridize electric vehicles for more range, less anxiety
Horse Powertrain goes the other direction from its electric motor lineup, developing an ICE generator designed to hybridize electric vehicles for more range, less anxiety

First things first: We just have to put some numbers around Horse's claim of briefcase-level sizing. The company is kind enough to list dimensions out in this week's sneak peek, speccing the C15 base unit at 19.7 x 21.7 x 11 in (50 x 55 x 28 cm).

In a modern workspace defined by remote work and digital product, I can't say I've ever had a reason to carry an actual briefcase so I have nothing around to physically compare those numbers against. Luckily, that same wide open digital space affords access to a boundless collection of numbers with which to compare. Taking a quick look around at a couple of actual briefcase models suggests that Horse is a little overly optimistic as to just how small it's managed to package the C15. Perhaps, it, too, hasn't held an actual briefcase in decades.

We weren't shocked to see that it had played a little fast and loose with its comparison in trying to craft a crisp, clear image of a small, lightweight combustion-generator. We found that actual briefcases, of both hard and soft varieties, over at Briefcase.com (still a thing!) and other retailers commonly ranged between 16 to 18 in (41 to 46 cm) long by 12 to 14 in (30 to 36 cm) high by 3 to 8 in (8 to 20 cm) thick. And that includes the big lugs in Briefcase.com's "Large" category (no XL category listed).

So clearly the C15 is a bit "larger than a briefcase," but we suppose it's close enough in a ballpark sorta way, especially since we're talking about a combination engine, generator, inverter, and exhaust and cooling hardware – a package we wouldn't have expected to size anywhere close to a briefcase at all.

But we'll all need to dissociate from any visions of black-suited Horse reps toting C15 engines around the garage in attaché cases.

Horse will show the C15 at next week's IAA Mobility Munich show
Horse will show the C15 at next week's IAA Mobility Munich show

In reality, the C15 will comprise a full family of drop-in range-extenders, and those afore-listed dimensions belong to the most modest of the initial units. The Euro 7-compliant naturally aspirated 1.5-liter four-cylinder puts out up to 70 kW (94 hp) of power to directly charge the vehicle's traction battery via its integrated generator and maintain charge level. It is not connected to the wheels so never provides direct drive power, allowing it to operate steadily in the optimal rpm range to further increase efficiency, cut emissions and deliver smooth performance.

The 70-kW version will be aimed at Europe's B and C vehicle segments, and Horse will also tack on a turbocharger to up power to 120 kW (161 hp) for larger D-segment and light commercial EVs. It doesn't list the dimensions of that one, so we'll spec it at "definitely larger and lumpier than a briefcase."

Aimed at integration by automakers and powertrain OEMS, the C15 units are designed to be installed horizontally or vertically and fit into the front or rear of the vehicle. The idea is to give manufacturers plenty of flexibility in transforming battery electric vehicle (BEV) platforms into range-extended series hybrids.

Beyond simply increasing range at the vehicle level, the C15 is also designed to allow OEMs to develop platforms around smaller battery packs, cutting overall weight and cost without an accompanying decrease in total driving range.

"Range-extended EVs (REEVs) are the fastest-growing powertrain category in many global markets," said Horse CEO Matias Giannini. "The Horse C15 range extender solution offers OEMs a straightforward and cost-effective way to tap into this opportunity and adapt their native BEV platforms into REEVs. We believe demand for REEVs will continue to grow; Horse C15 will play a critical role in this transition."

Like the Future Hybrid Concept powertrain Horse previewed at Auto Shanghai in the spring, the C15 is designed around multi-fuel capability. It can be powered by gasoline, ethanol and methanol flex fuels, and synthetic fuels, giving manufacturers another flexible tool in making vehicles cleaner and more efficient overall.

Horse plans to give the industry its first full look at the C15 series at IAA Mobility 2025, which starts in Munich on Monday. We'll see if the company doesn't have more details and performance estimates once the C15 makes its full premiere.

Source: Horse Powertrain

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17 comments
17 comments
Nobody
I have always said that every EV should have a trailer hitch to pull a small generator and fuel supply for extended ranges. Perhaps that won't be needed around town but many of us travel considerable distances on a regular basis. Range anxiety is a real thing that could be easily addressed for a reasonable price. Perhaps much cheaper than a hybrid vehicle.
Electrowin
Seems a more accurate description would be “carry-on size.” At least an analogy that more people would recognize.
Snevo61
The article doesn't say potential kwh charging rates? A 70kw ICE sounds over generous, as wouldn't it be able to put out at least half that (35kw) in electrical power? All sound ok, but the "briefcase " still needs a fuel tank, air intake / air cleaner, exhaust system, cooling system / radiator, heat protection etc. There are already many small cars with small 3 and 4 cylinder motors that, once stripped of gearbox and all of the above, would probably be about the same size. Why is this engine any different?
I do like the concept though, at least if you ran out of battery power and no charger within coo-ee, at least you could get going again after a couple of hours hopefully?
JGTinNJ
Dwelling too much on the briefcase description for size. If it is ultra compact compared to other solutions one could imagine using "pocket sized". It sounds like a good concept, although I suspect there are different ICE technologies that would make that portion of the unit even more compact.
JøhP
A 70 kW engine in a series hybrid is a significant over-provision for its role as a generator, which only needs to supply the power for the vehicle's electrical consumption. The average EV uses between 15 to 20 kWh per 100 km, meaning its average power draw is well under 20 kW. The proposed 70 kW engine is likely two to three times larger than what is actually needed for efficient operation. Intermittent operation prevents the engine from consistently reaching its thermal optimum, the specific temperature range (typically 80-120°C) where it operates most efficiently. This stop-and-go thermal cycling would compromise fuel efficiency.
SteveMc
The Euro 7 classification is the only really interesting part of this information. ‘What kWh rate does it charge the vehicle’ is the important data. The suggestion of 35 kWh is doubtful, to say the least. Keeping the generator compact, I’m guessing at kWh? Ive seen plenty 35kWh generators and some are as heavy as a small car and almost the same size!
SquareStem
Now you have to maintain 2 power trains and you can bet the stealership and manufacturer's warranty terms will still need you in at the same intervals for oil changes, timing belts, tuneups etc even though you may hardly have used the ICE. Still a nice little air polluter too. What is needed in the EV context for the relatively few people who routinely drive long distances is faster charging, with decent availability. And only 2-5% of people do more than 125 miles per day in the US so this whole discussion is for a small niche of the market. That said, the need is still legitimate but the hybrid 'solution' isn't the best way to do this IMO.
BanisterJH
I think the notion of a generator set with a physically small engine for range extending is a good one. You could easily remove it and do repairs on the bench, or repair shops could easily swap in loaner engines so vehicle owners don't have to wait. However, I'd rather see them using a free piston engine. You don't have to go round and round to make DC. Koenigsegg's electrically actuated valves and a set of double ended free pistons would make for a lot fewer moving parts.
martinwinlow
@ Nobody - Sorry but you are about 5 year behind 'everyone' else. Modern EV range is entirely adequate for the vast majority of motorists *now*. Hybrids (of whatever type) have their uses but it is a small and dwindling market... and good riddance to it.
Captain Danger
@Snevo61 50% efficiency sounds pretty low to me but even at 50% that's 40 hp which is plenty to keep a car moving. The batteries can fill in for accell. and in slower or stationary conditions excess power can be used to charge.
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