Bit of electronics for a change, circuits, chips! yummy jummy! (2023 Update)

It was something really odd like 42 volts from three 12 volt batteries. Real solid math behind all of it, no matter sort of weird floating charge fantasy math they were using.

It's really not even clear what the goal was. 24 volts would have been easy enough to implement. without some really goofy battery setups.

That would be hard on the battery. I wonder how good the warranty is. ;)

Depends on what the actual current is. My 80 kW motor typically draw around 70A (28kW) on local driving. Anyone got data on other EVs?

Formula E is racing, there's a 52kWh net energy allowance for a 45 minute race and afair they claim regen adds about 40%

What's the typical power/current draws? 52kWh/0.75 = 70 kW average?

600kW is beyond the output of my model X, even in Ludicrous mode. I've never seen the car charge at faster than about 170 kW. I don't give a damn what the current is. The battery is not remotely designed to charge at 600kW! That might well rip all the tires loose from the pavement, if the traction control didn't kick in reducing the regen. It certainly feels like the regen is kicking in when it goes all out on acceleration at ~500 kW and 600+ HP. The car has a subtle side to side shift.

Not for charging. 600W (1500A) max discharging/driving. But we want to know the typical, not just the max.

it is racing so pretty much constantly switching from max power to max regen

they claim ~40% of the energy used is regen, so 52kWh battery + ~35kWh regen = 87kWh , so ~116kW average

That's pulling regen energy out of nowhere. I think it just mean more distance out of the 52kW battery.

it is not energy out of nowhere, it is reusing the energy rather turning it into heat in the brakes

netto, if they didn't have regen they would need a battery nearly twice the size to go as fast

So, if we go constantly on flat land, we have 52kWh battery. But if we go over a hill, we got 87kWh battery?

many hills. e.g. if it takes 5kWh to get up the hill you can go up and down the hill 10 times with a 50kWh battery if you can regen 3kWh every time you go downhill, you can go up and down the hill the same 10 times with just a 20kWh battery

What use is the average as calculated from the battery and the regen use? Is this about determining the cooling requirement?

The motor sees the energy from the battery, then the energy from regeneration, twice, once in each direction.

What are you trying to figure out???

The motor uses extra energy to go up the hill, then regen back the extra energy. But it's the same 52kWh, not an additional 35kWh.

Where that extra 35kWh is coming from.

more like three times, battery to motor, then motor to battery, and finally battery to motor

they spend all the energy allowed, you can on the last lap they are all close to zero percent left of the 52kWh net allowance

it isn't "extra" it is saved by not heating the brakes. So you do 87kWh worth of acceleration using 52kWh of energy

But you know where it comes from, the regen. If you simply reject the idea that regen gives you an extra 35 kW, then you can't understand, by definition.

I saw a review of a BMW BEV which claimed more than 100% efficiency because they were adding some percentage for the regeneration. They obviously were not trying to say the car generated energy from nowhere. It was simply a fall out of accounting for the fact that energy which would have been wasted in a car without regeneration, would have used a lot more energy. Figuring it the way they did as "efficiency" is bogus. However, counting it as 35 kW of "free energy" is totally accurate. It's no different than if you had an extra 35 kW battery and no regen.

This is just a comparison to a car without regen. That car wastes the 35 kW by making heat somewhere, in the brakes usually, or in the engine if using engine braking.

This is not the Monty Hall problem. It's not impossible to understand unless you simply refuse to understand.