Interesting as what you say is, I have some trouble with those numbers. I took the SLS AMG Electric Drive for comparison to get a rough idea how energy relates to weightdren wrote:OK, found that a typical KERS system weighs 35kg from Formula 1 official website. I'm guessing this is a bit high by todays standards, but I have no idea. The max ES is 400kJ. The increase for 2014 is to 4MJ, 10x. I don't know how energy storage weight increases vs energy capacity. I'll make an assumption that the battery part is roughly a third of the weight, that's 10kg for batteries to store 400kJ. Increase the capacity to 4MJ and if weight increase is linear, that's 100kgs worth of batteries.
The MGUs will be fairly heavy with 120 kW and and perhaps 45 kW respectively. Have a look what what a conventional AC servo motor of that power weights.tim|away wrote:A couple of thoughts on the weight changes for 2014:
- the minimum weight has been increased to 690kg, up from 642kg this year
- fuel load will be down by roughly 50 kg (see my post above)
That leaves us with at least ~100kg for ERS and the turbo and the additional cooling. Worse still, this allowance doesn't take into account that the engines will be lighter due to fewer cylinders or the lack of KERS unit in 2014. Having said that, even a 100 kg allowance for the turbo, ERS and addtional cooling does seem rather excssive if you consider that the whole V8 engines this year weigh slightly less than that (95kg) - realistically this allowance is probably more than 130kg even (and that is a somewhat conservative guess). Have they increased the weight limit a bit too much?
You cannot use that SLS AMG figure because the battery is designed to last several years. F1 batteries are throw away items. They will be exchanged for every race. It means that they can thermally stress the batteries much harder and have to carry much less weight.tim|away wrote:Interesting as what you say is, I have some trouble with those numbers. I took the SLS AMG Electric Drive for comparison to get a rough idea how energy relates to weightdren wrote:OK, found that a typical KERS system weighs 35kg from Formula 1 official website. I'm guessing this is a bit high by todays standards, but I have no idea. The max ES is 400kJ. The increase for 2014 is to 4MJ, 10x. I don't know how energy storage weight increases vs energy capacity. I'll make an assumption that the battery part is roughly a third of the weight, that's 10kg for batteries to store 400kJ. Increase the capacity to 4MJ and if weight increase is linear, that's 100kgs worth of batteries.
"The high-voltage battery in the SLS AMG Coupé Electric Drive boasts an energy content of 60 kWh, an electric load potential of 600 kW and weighs 548 kg" (source)
That's 216 MJ at 548 kg if I'm not mistaken. If we were to go by this number and the relation between energy storage and weight was linear, the batteries to store 4 MJ would weigh in at around 10 kg. That's a factor 10 off of your figures.
I am very well aware of that, but that would reduce the weight even more and supports my point. As for your previous post (which was very interesting by the way), I also looked up the powertrain of the SLS AMG electric drive for comparison.WhiteBlue wrote:You cannot use that SLS AMG figure because the battery is designed to last several years. F1 batteries are throw away items. They will be exchanged for every race. It means that they can thermally stress the batteries much harder and have to carry much less weight.
http://www.greencarcongress.com/2010/11 ... -7-kg.htmltim|away wrote:Interesting as what you say is, I have some trouble with those numbers. I took the SLS AMG Electric Drive for comparison to get a rough idea how energy relates to weightdren wrote:OK, found that a typical KERS system weighs 35kg from Formula 1 official website. I'm guessing this is a bit high by todays standards, but I have no idea. The max ES is 400kJ. The increase for 2014 is to 4MJ, 10x. I don't know how energy storage weight increases vs energy capacity. I'll make an assumption that the battery part is roughly a third of the weight, that's 10kg for batteries to store 400kJ. Increase the capacity to 4MJ and if weight increase is linear, that's 100kgs worth of batteries.
"The high-voltage battery in the SLS AMG Coupé Electric Drive boasts an energy content of 60 kWh, an electric load potential of 600 kW and weighs 548 kg" (source)
That's 216 MJ at 548 kg if I'm not mistaken. If we were to go by this number and the relation between energy storage and weight was linear, the batteries to store 4 MJ would weigh in at around 10 kg. That's a factor 10 off of your figures.
I was guessing 10kg for batteries now in 2013... I'm assuming you're refering to me?WhiteBlue wrote:No way! We have pretty solid data that the batteries are 35 kg in 2014 for a capacity of 4MJ.
WhiteBlue wrote:No way! We have pretty solid data that the batteries are 35 kg in 2014 for a capacity of 4MJ.
2.25 kg/MJ compared to the SLS AMG figure of 2.53 kg/MJlangwadt wrote:sounds very heavy, I looked up the Tesla battery 450Kg- 200MJ, so 9Kg - 4MJWhiteBlue wrote:No way! We have pretty solid data that the batteries are 35 kg in 2014 for a capacity of 4MJ.
The battery capacity of an F1 is not determined by the unloading or drainage speed but by the loading speed. You have 55s to drain 4MJ but you have only 8s to load 2 MJ because of the limited braking time. So the critical transfer rate is 225 kJ/s or 225 kW charging power. If you compare that to the Tesla motor that drains at 306 kW you get a percentage of 72.6%. The F1 battery would have to weight 400 kg. or the installed capacity would be 223 MJ. I think F1 is not doing so bad with 35 kg for this kind of charging rate.dren wrote:http://www.teslamotors.com/fr_CA/forum/ ... -battery-0
Model S:
Largest battery holds 85kWh (306MJ). Motor makes 310kWs.
They are estimating 535kg to 556kgs, but I can't find an actual number.
You are jumping to the wrong conclusions IMO.dren wrote:Right. If you use the 93% generating efficiency the Honda KERS had, you're looking at a time of 18 seconds needed during a lap to charge 2MJ, and that's assuming the motor will be designed for the full 120kW output. And like I stated before, all 100% braking energy will not go into the MGUK during braking. So we are either looking at a much smaller battery storage system, a much larger recovery from the MGUH, or an overall reduction in the ERS size, weight and output.