Formula E

[Andres125sx]

and low power? the cars mentioned above are able to run a complete race distance whilst being much heavier.

I´m sure you know those mileage numbers are the best possible they can achieve, but at racing pace they will be reduced maybe to 1/3 or 1/4, so no, they cannnot run a complete race distance even when they´re much heavier

Volkswagen claims his Golf can do 1000km, and it can, but at racing pace (wich is different to driving fast) I´d be surprised if it can do 400km

Maybe FE could have avoided the car change with double the batteries, but then they´d be a brick with four wheels...

Maybe they´re keeping in mind LiS and LiO batteries, replacing current batteries with LiS batteries they´d be able to run the whole race without any car change, and they´d be keeping more or less the same weight they´re now

[autogyro]

The initial technical purpose of FE is to encourage the development of better batteries.

[henra]

~25% of the 30kWh that the final cars should have.

30kWh?
seriously?

That's not much mocre than the amount you would use in a Smart City Road Car.
The Tesla has 50-60kWh IIRC, and that is existing since quite a few years.
You would have thought that an electric Formula Racing series starting in 2014 would move a little further.
I would have thought they would use somewhere between 50 and 100 kWh.
This is ridiculous.

[henra]

The low power is probably due to a combination of range and cost concerns with respect to the size of the batteries.

Come on!
When using available LiPo technology, an 80kWh battery would be somewhere around 30k€.
Compared to the general cost of participating in a racing series that is completely peanuts.
Problem is more related to the weight.
An 80kWh battery will be around 400 - 450kg.
At least 40-50kWh would have been desirable IMHO.

[theblackangus]

The low power is probably due to a combination of range and cost concerns with respect to the size of the batteries.

Come on!
When using available LiPo technology, an 80kWh battery would be somewhere around 30k€.
Compared to the general cost of participating in a racing series that is completely peanuts.
Problem is more related to the weight.
An 80kWh battery will be around 400 - 450kg.
At least 40-50kWh would have been desirable IMHO.

From my basic reading Lipo's are very dangerous batteries. (Looking to learn more here)
They have to be charged very carefully, and the risk of failure from impact/defects/charging issues is higher than other LiX batteries. (?)
Lipo's are used for various RC vehicles, there are videos of helicopters burning up mid air for no apparent reason. (I believed this is caused by cell charge imbalance.)

Anyone know enough to talk to the differences between battery types and why FE chose the type they use?

[Andres125sx]

~25% of the 30kWh that the final cars should have.

30kWh?
seriously?

That's not much mocre than the amount you would use in a Smart City Road Car.
The Tesla has 50-60kWh IIRC, and that is existing since quite a few years.
You would have thought that an electric Formula Racing series starting in 2014 would move a little further.
I would have thought they would use somewhere between 50 and 100 kWh.
This is ridiculous.

IMHO ridiculous would be using a battery that weighs 500kg into a single seater, and a 100kWh battery must be around 800kg

Tesla Roadster battery is 53kWh and weight 400-450kg, so I guess FE battery must be around 200kg, what I think is reasonable for a car this type

Battery technology is supposed to improve soon, and I think they have this in mind. If they want to use current batteries for the whole race then it would be 400kg heavy, probably too much for a car this size. And when LiS batteries are finally available the battery weight will be reduced to a half, and reducing 200kg of weight would change the cars too much

But if they put a battery for half the race now, when LiS batteries are available they will be able to do the whole race in a row with a battery the same weight they are now (more or less), so the cars wouldn´t change. This is just speculation, but I think it make sense, there´s no reason to build a new car around a battery technology you know will be out-dated soon

IMO FE will be some sort of test bench to evolve the techonolgy and cars, but current batteries are not good enough yet and force to do weird things like the car change for a decent distance race. It will be with LiS or LiO batteries when IC engines will be definitely obsolete both for racing and for production cars, right now the weight of the battery and/or the little mileage are too big cons, but with lighter batteries every single aspect will be better on EVs, cost, lifespan, maintainance, perfomance, ease of use, smoothness, weight, handling.... so it´s worth to start introducing into this new technology asap

[Lycoming]

I believe they would be using LiFePO4 batteries. At least, that's what they should be using. Absolutely not the best power density available, but it's less prone to randomly lighting on fire, thermal runaway, etc.

[Blanchimont]

The technical regulations: http://www.fia.com/sites/default/files/ ... 2013_0.pdf

The battery/capacitor must not be heavier than 200kg and the total car weight has to be no less than 800kg (§5.1). At first this looks like the car with the best power and energy density will win, but $7.6 limits the total power to 200kW and the total energy available to 28kWh plus the energy that can be recovered under braking. I'd like to see a change in this article so that the total weight stays at 800kg, but the battery limit is gone. Or the total weight limit could be claculated as 600kg plus the battery weight. Or both weight limits stay and the amount of energy could be free.

Article 10.4 forbids torque vectoring, i hope this is changed for 2015.

[Andres125sx]

The low power is probably due to a combination of range and cost concerns with respect to the size of the batteries.

Come on!
When using available LiPo technology, an 80kWh battery would be somewhere around 30k€.
Compared to the general cost of participating in a racing series that is completely peanuts.
Problem is more related to the weight.
An 80kWh battery will be around 400 - 450kg.
At least 40-50kWh would have been desirable IMHO.

From my basic reading Lipo's are very dangerous batteries. (Looking to learn more here)
They have to be charged very carefully, and the risk of failure from impact/defects/charging issues is higher than other LiX batteries. (?)
Lipo's are used for various RC vehicles, there are videos of helicopters burning up mid air for no apparent reason. (I believed this is caused by cell charge imbalance.)

Anyone know enough to talk to the differences between battery types and why FE chose the type they use?

One of my hobbies is RC planes, and I´m using LiPo batteries for more than 10 years now. 10 years ago there was a lot of scare about LiPo batteries, and there were videos all around about batteries in flames....

But that was only a combination of two factors, new batteries and people using them as NiCd batteries. First LiPos did lack discharging rate, at 10/15C they were pushed too hard too frequently. And people was not used to soft batteries that are damaged easily in a crash (NiCd batteries have a hard case and can take a lot of abuse so people was not used to worry about the battery), so when you use a damaged battery and push it hard.... it may go in flames.

Another point was the charger. If you charge a Lipo battery at a different program (NiCd, NiMh, Pb...) it will go in flames too.

But those are normal problems for new batteries, remember I´m talking about 10 years ago. Now I don´t see a video of a Lipo in flames or hear about it for a lot of years. Now batteries can take discharge rates of up to 60C so they are much more difficult to push, and people know how to use them properly

I´m using cheap chinese Lipo batteries for those 10 years and have never had any single problem. Once I even tried to cause a shortcircuit with an old battery I was going to retire to see if it goes in flames... and nothing. I think safety of Lipo batteries did improve more than enough some years ago, now they´re as safe as any other battery, if you know how to use them there´s no problem. And my experience is with Lipos from a sector were I+D is quite low compared with automotive industry, and into that sector I´m using the cheapest batteries I can find (1/3 of first brands price) so a Lipo built for a car with the proper quality controls I think would be pretty safe

But I´ve wondered why they use LiIon instead of Lipo many times, so there must be something I´m missing...

I believe they would be using LiFePO4 batteries. At least, that's what they should be using. Absolutely not the best power density available, but it's less prone to randomly lighting on fire, thermal runaway, etc.

LiFePo4 or A123 batteries are much easier to use than LiPo or LiIon because they can be charged much faster without any problem, and also they can be discharged to 0 volts without any damage for the battery (LiPo and LiIon should never go below 3 and 2,7 volts or they will be damaged) so they don´t need any special care.

But energy density is a bit lower than LiPo and LiIon batteries, and that´s the main problem for current batteries so LiFePo4 actually don´t solve the problem, they only are another option to LiPo and LiIon.

It´s LiS what will be a significant change, they´re suposed to duplicate energy density of current LiXX batteries

And LiO are supposed to be the next step after LiS, they should improve energy density of current batteries by a factor of 4-6. Imagine current electric cars with a battery half the weight it has now, but with double the mileage... for example a Tesla Roadster 220 kg lighter than today (1000kg) and double the mileage it can do now (700km/440miles)...

[andylaurence]

Power density isn't the problem for electric cars though. We can already discharge at 60C. That's the whole pack dead in a minute. Even in my short sprints that's quick enough that I would need to recharge between runs. The energy density needs to increase. Carrying 200kg of batteries for a 20 minute race isn't much cop. That's a 50% increase in weight for any self-respecting single seater of under 300bhp.

I don't understand why they didn't go for a few 20 minute sprint races rather than a whole 60 minute race with two mandatory stops. When energy density increases significantly, then either drop the minimum weight limit or increase the race distance. I can't see people finding a running race in the middle of a motor race very exciting and there's a reason they stopped running to cars at Le Mans...

[Andres125sx]

Sorry you´re right, it´s energy density what I was talking about, my english...

I´ve edited the post, thanks andylaurence

[henra]

IMHO ridiculous would be using a battery that weighs 500kg into a single seater, and a 100kWh battery must be around 800kg

Tesla Roadster battery is 53kWh and weight 400-450kg, so I guess FE battery must be around 200kg, what I think is reasonable for a car this type

100kWh shouldn't be 800kg with the current Technology anymore.
When using cells with a continuous C- Rate<5 you should be able to squeeze 100kWh into 500kg.
So with a 300kg battery you should be able to get at least 60kWh.
When using DC electric Motors the drive unit itself shouldn't be too heavy (<50kg) and you don't need a shifting gear and the huge radiators, oil/water or other crap today''s F1 cars have to take along for the ride.
Therefore I would expect a Formula car with a 300kg battery to end up around 800kg max including Driver.

Re: dangerous LiPo/LiIon batteries: Indeed if crushing them seriously you might have an incresed risk of fire but the same applies to a 200 Liter full of High Octane Fuel.
Apart from damaging them in a crash the cells today are rather well understood and the risk was considered so low that they were accepted as Board Batteries on the newest Airbus and Boeing Airliners. Admittedly Boeing had some issues in that regard but still they were accepted in the first place by FAA and EASA. And those are normally way more picky than FIA.

[Andres125sx]

IMHO ridiculous would be using a battery that weighs 500kg into a single seater, and a 100kWh battery must be around 800kg

Tesla Roadster battery is 53kWh and weight 400-450kg, so I guess FE battery must be around 200kg, what I think is reasonable for a car this type

100kWh shouldn't be 800kg with the current Technology anymore.
When using cells with a continuous C- Rate<5 you should be able to squeeze 100kWh into 500kg.

Batteries with low discharging rates have a little bit better energy density, but never to almost duplicate it as you´re stating, 500kg for a 100KWh battery is way way too optimistic.

If you take FE batteries as a reference (they should be the best out there), a 100kWh battery should be 666kg heavy, 33% heavier than you say

[andylaurence]

Batteries with low discharging rates have a little bit better energy density, but never to almost duplicate it as you´re stating, 500kg for a 100KWh battery is way way too optimistic.

If you take FE batteries as a reference (they should be the best out there), a 100kWh battery should be 666kg heavy, 33% heavier than you say

I agree that 500kg might well be optimistic, but it only took me 5 minutes to find 590kg for 100KWh. Admittedly, you'll need BMS on top of that, but even 5C cells can deliver over 650bhp peak with that size of pack.

[Andres125sx]

I guess car batteries must include the cooling system, that pack is for an RC plane where it gets tons of cooling, but a car does need liquid cooling for the batteries

Manufacturers are the most motivated to reduce battery weight, so if there´s no car with those numbers there must be some reason like the cooling. They also need some shielding or protection to resist any accident, that may be another reason wich increase the weight and lower the energy density

I´m assuming the battery weight they declare is the complete package ready to run, not just the loose cells


BTW, what´s BMS?