Many year lurker here, nice to finally interact with you all. This is a topic I ambivalently care a great deal about. While uncomfortable to me, at least it keeps me somewhat objective on the pros and cons,
This will be nerdy and long but hopefully still accessible to many.
Those who prefer shorter posts, just skip this one. You're welcome and appreciated.
I've been an intent follower of the rise of BEVs, startups and legacy brands, and the design decisions made.
Formula E season 1 almost had the right idea. They should not have changed the car, but rather the battery.
Think about it. In our everyday lives, we change batteries a lot. Nowadays even on vehicles that are vital for our life style. Electric skateboards, kick sooters, ebikes, etc. The electric rent mopeds than litter the sidewalks, have drive batteries that are swapped in seconds. Many privately owned mopeds are the same. You carry the battery up to your apartment to charge it near the front door.
Main exception: laptop and phone makers are collectively pushing us away from battery swaps. Battery dies, laptop dies, 'mkay? You want an updated model anyway, right? Only makes sense to make the battery more integral the phone/laptop, light and sleek as you like it.
Race cars being so far from a consumer product, for all it's "road relevance", might as well be designed around a hot swappable drive battery. Manually operated jacks could lift and pull them out/push in. To lock the battery in place, I can see the wheel guns used. Next to each bolt a light comes on when it's done up properly. Car won't even go into drive until all bolts are showing green.
With a clear vision, such cars need not be ultra heavy. Already "long range" BEVs on the road are similar in weight to PHEVs. The biggest Tesla saloon, real peppy on a short track session, faster than most 4-doors ever made, doesn't really weigh more than a PHEV saloon from BMW, Mercedes, Audi or Porsche. That is to say, PHEVs are made in a way that has them be porkers just like BEVs.
Some car brands are claiming that the structural integrity of the battery is adding to that of their BEV. Not unlike ICEs have been for (race)cars for several decades.
In an open formula, designers would undoubtedly explore this. Without battery, the car is strong enough to be wheeled around and be worked on, but not to take a curb stone or protect the driver. Little bit (really not a lot, with carbon monocogs) saved in total weight there. The battery being swappable in theory adds weight, but that difference would diminish over time.
Having hot swappable batteries (and yes, for safety a drive battery could be low voltage when outside the car, only close relays to go high voltage when well installed) would remove the whole fast charging debacle that FE has worked on....and backed out of. With over a decade of successful fast charging in the consumer market....but only with one brand who took it seriously, with a passion.
I watch Indycar, I like Indycar. Actually, their stints are quite short. The cars are rather fuel mileage limited than tyre life limited, it seems. Much like BEVs being races, then. According to my estimates, a BEV race car designed with proper commitment, at least one continent away from Paris where good racing ideas seem to die in their infancy...we could have Indycar/F2/LMP1 level racing on all-electric drive. Just takes the hot swap and a central design of aerodynamics. "Open wheel" is what FIA granted FE it's 25 year green monopoly for, as if open wheels is such a fringe way of making cars. And it is. Near zero road relevance is left, and it's exceedingly bad aerodynamically. An LMP style body needs so much less power to cruise at 300 kph, it's not even funny. The Hypercar rules are making closed wheel aero seem horrible, but it's actually been amazing in decades past.
Indycar and F2 are spec series, LMP2 effectively as well. A central designer could simply (yes, simply) try harder on aero than on "make it look open wheel", and our BEV racer would be exceedingly efficient at high speeds. Allow active aero? Well that makes it even more interesting, technically. And even slightly road relevant, as that feature is actually on sale for cars with license plates. Where Hypercars can't have better than 4:1 lift to drag, the spec racer could be 6:1 probably, with active aero to reduce drag more on straights and increase downforce more in the few seconds around the lap where that is most crucial. Brake zone, corner, and maybe exit.
In sci-fi terms, the ideal BEV racer (stuck with a super energy un-dense power source) would have memory skin that shifts between the looks of an Mercedes EQXX style streamliner and a Porsche 919 Evo (LPM1, but no rules, full F1 level lap times with much higher top speeds). It would even get narrower down straights. None of that is practical today of course, but it's to paint the kinds of things that would make batteries less terrible an idea for a race car.
Personally, I feel F1 is faster than it needs to be. We can afford to have F1 take 10 seconds longer per lap. Just please don't let any FE-ness trickly into F1 because someone at the top heard something about hybrid to fuel ratios and wanted it.
Batteries being so exceedingly heavy, potentially dangerous, and vastly different between consumer car brands, a non-normalized series would have one car slaughter the field, but perhaps it would be a different car depending on the circuit. Winning Monza and Monaco are obviously different tasks.
It's quite doable to up Formula E's battery from 40 kWh usable (really tiny in road relevance terms) to 80 kWh usable, shorten the stints, add proper slicks, add real aero with strong DRS, and get stints at the pace and length of Indycar.
Touring cars/GT: Various road BEVs have between 70 and 92 kWh usable. Redesigning those to allow for in-race battery swaps on par with reasonable refueling...can be done, but would kind of ruin the "I have that car" vibe of touringcars. Trying to get 1-hour races from that would be a great way to make BEVs look useless to the 5 or 6 people that show up to watch the race. 3x 20 minutes with not too gimmicky twists would allow for casual fast charging rather than in-race which would not be something I'd want to be connected to with sponsorship or reputation. You think Hockenheim 1994 was bad due to racers wanting a quicker fill-up?
With swappable batteries, whichever race series, the races can be long, even 24h long. Even Dakar long.
In GP style racing, the batteries could come in weight groups. Say, 300kg, 400kg and 500kg. If different dimension to fuel loads and tyre compounds, for instance. Nowadays we can test race such concepts long before we make the effort of actually designing it. Yes, rule could be that you start the race on the battery you used for qualifying. Let's say, on full charge to make it less stressful. Use each battery in the race? Or, use at least 2 and fast-charge mid-race at a modest nominal power level. The swapping concept opens for many design choices that can positively impact racing.
Another option is to have a small power cell battery (like in plug-in hybrids) bolted to the chassis. This works like the traction battery in F1 and LMP1. Charge under braking, discharge out of corners of for extra top speed. At times, charge at the cost of ICE or larger drive battery. A small battery like this is very weight-efficient. Adding a no-rules ERS system to an ICE race car, will just make it faster and/or use less fuel. Depending on the actual state of the art of "range cell" battery technology, having this on board power battery could save weight and have larger swappable drive batteries be stressed less. Example: max regen into on board small battery 400 kW, output maximum 200 kW, no limits per lap. Drive battery unlimited regen, deployment 400 kW. 600 kW peak = 800 hp, good for Indycar and F1 and LMP1 style racing. Stint length will be under pressure with such output, obviously, but such drivetrains can be made. Regardless of whether I feel it actually makes sense.
As you'll get from the subtext, I'm thoroughly obsessed with BEVs for what they are. Much less so for what they're made out to be socially and politically. Batteries are barbaric quasi-tech objects in my opinion, and the better alternatives (wireless power transmission over distance for instance) described by true science legends are simply not pursued with grant money or startup billions. The only thing "better" than a car with a big battery, is a car without a big battery. And oh do I ever lust after big battery vehicles... Just one of those human obsessions, doesn't make the object of it a good thing.
Various companies are developing battery cells with vastly better specifications than commercially used today, for instance by car brands and Formula E.
Racing ought to be right on top of those developments and acquire batches of cells to go racing with. Pushing the envelope, remember that?
Let's say Formula E used 250 Wh/kg cells, when they might well be able to acquire or produce enough cells with 400 Wh/kg to build a fleet of cars with. Just removing the old battery and sticking in the new would allow much harder racing for the same number of laps with much less or no cycling peloton driving. Or take those 45 minute races to GP spec Monza. And frankly, they could add some weight, get LMP level slicks and lap much faster still. The next step to swappable batteries would then make full distance GPs possible, at GP style speeds. Not today's F1, that's just not possible even if I stretch my imagination. But F2 pace, that is a lot more accessible.
With BEV style race cars, one lap pace isn't the issue, it's longer race pace. It just takes a lot of energy to race any amount of time, hence large tanks on race cars and where we can drive for 5-10 hours before refuelling, race cars barely last an hour on an extra large tank. Batteries are a bad idea for racing, but it can be done. I just don't seem people with any vision that would self-serve involved. The things I see appear to be there to slow down BEVs ascension to normalcy. We can't do a lot about the sound (unless we fake it with speaker), but the racing is possible to any level we reasonably want. I think 1994 F1 cars were pretty awesome. The speed I can give with on battery power, the sound not really.
In closing, I love the McMurtry Speirling concept. Its main flaw is the non-swappable battery, obviously. It's narrow, but fun. Fan ground effect, need I say more? I want to see 20+ of these duke it out around various GP tracks and perhaps more curious tracks. Less tractive power, half even, would probably be fine still.
Can touring cars be modified to have a McMurtry style ground effect system? Then surely it can be made to work with a large battery. Yes, please!
Imagine it, sleek true silhouette touring cars with tons of fan car ground effect for spectacular cornering and Super GT like lap times..
