F1technical.net

no surprise... i think mclaren had an advantage in weight and low COG......they lost that this year and it shows in the handling...

subcritical71 wrote: ↑

11 Oct 2018, 15:32

Interesting comparison between the Honda and Ferrari battery posted on the Honda forum. If they do indeed both use the same Saft batteries there is an obvious difference in implementation! It could just be perspective, but the size of that Ferrari battery is staggering in comparison

Speculation. Are we looking at the difference between a Ferrari combined ERS with control unit, and the Honda which is a discrete unit?

turbof1 wrote: ↑

11 Oct 2018, 14:26

At this level I honestly think it goes a bit deeper than that. I don't think it is like "here you go, these are our cells. Here's our advice on how to use them". Ferrari will have specific requests on shape, charge and discharge, on how to integrate them with their control unit software. That requires a strong partnership, not just a supply/demand contract.

If it's a strong partnership, the depth of cooperation knows almost no limits. It could go as granular as how to best ramp up and ramp down the the charge/discharge interaction to increase cell longevity. Companies can make huge strides when they start openly sharing IP.

dans79 wrote: ↑

11 Oct 2018, 17:23

turbof1 wrote: ↑

11 Oct 2018, 14:26

At this level I honestly think it goes a bit deeper than that. I don't think it is like "here you go, these are our cells. Here's our advice on how to use them". Ferrari will have specific requests on shape, charge and discharge, on how to integrate them with their control unit software. That requires a strong partnership, not just a supply/demand contract.

If it's a strong partnership, the depth of cooperation knows almost no limits. It could go as granular as how to best ramp up and ramp down the the charge/discharge interaction to increase cell longevity. Companies can make huge strides when they start openly sharing IP.

Fully agree there.

Vortex37 wrote: ↑

11 Oct 2018, 17:15

subcritical71 wrote: ↑

11 Oct 2018, 15:32

Interesting comparison between the Honda and Ferrari battery posted on the Honda forum. If they do indeed both use the same Saft batteries there is an obvious difference in implementation! It could just be perspective, but the size of that Ferrari battery is staggering in comparison

Speculation. Are we looking at the difference between a Ferrari combined ERS with control unit, and the Honda which is a discrete unit?

Being supplied by the same makers of battery cells does not mean being supplied with the same specifications and shape of battery cells and neither does it mean that the ES as a unit will end up having the same configurations. People in the know said that within the rules/regulations as to weight and size a formula one battery capacity of 12mj is possible.

saviour stivala wrote: ↑

11 Oct 2018, 20:12

Vortex37 wrote: ↑

11 Oct 2018, 17:15

subcritical71 wrote: ↑

11 Oct 2018, 15:32

Interesting comparison between the Honda and Ferrari battery posted on the Honda forum. If they do indeed both use the same Saft batteries there is an obvious difference in implementation! It could just be perspective, but the size of that Ferrari battery is staggering in comparison

Speculation. Are we looking at the difference between a Ferrari combined ERS with control unit, and the Honda which is a discrete unit?

Being supplied by the same makers of battery cells does not mean being supplied with the same specifications and shape of battery cells and neither does it mean that the ES as a unit will end up having the same configurations. People in the know said that within the rules/regulations as to weight and size a formula one battery capacity of 12mj is possible.

Up to now the FE battery, supplied by Williams, was 100mJ weighing 200kg. With this technology 25kg of F1 battery would, as you say, be around 12MJ.

Next seasons FE battery, supplied by McLaren, will be 195mJ with “similar” weight. For some reason the FIA omit article 8 covering the ES from the published regulations so I can’t find the actual weight.

So state of the art for F1 is likely to be rather more than 12MJ.

henry wrote: ↑

11 Oct 2018, 23:34

So state of the art for F1 is likely to be rather more than 12MJ.

"Energy density: up to 385 Wh/l and 180 Wh/kg" - Saft
So 13MJ for 20kg battery

sosic2121 wrote: ↑

12 Oct 2018, 01:15

henry wrote: ↑

11 Oct 2018, 23:34

So state of the art for F1 is likely to be rather more than 12MJ.

"Energy density: up to 385 Wh/l and 180 Wh/kg" - Saft
So 13MJ for 20kg battery

Probably a bit less given there's mass in sensors, cables, cooling, etc. Probably more like 12MJ for a 20kg battery, which seems about right. That is enough reserve capacity to do half a season.

sosic2121 wrote: ↑

12 Oct 2018, 01:15

henry wrote: ↑

11 Oct 2018, 23:34

So state of the art for F1 is likely to be rather more than 12MJ.

"Energy density: up to 385 Wh/l and 180 Wh/kg" - Saft
So 13MJ for 20kg battery

A good recent article (http://www.powersourcesconference.com/P ... s/21-3.pdf) on Saft pouch type battery testing. Figure 1 shows the tradeoff between specific energy and power which may greatly effect battery performance. Of note is the last page in the article where it talks about solid state batteries. This could be (or maybe already is) technology F1 will adopt.

turbof1 wrote: ↑

12 Oct 2018, 11:38

sosic2121 wrote: ↑

12 Oct 2018, 01:15

henry wrote: ↑

11 Oct 2018, 23:34

So state of the art for F1 is likely to be rather more than 12MJ.

"Energy density: up to 385 Wh/l and 180 Wh/kg" - Saft
So 13MJ for 20kg battery

Probably a bit less given there's mass in sensors, cables, cooling, etc. Probably more like 12MJ for a 20kg battery, which seems about right. That is enough reserve capacity to do half a season.

You are right but I believe rules dictate battery pack to be between 20 and 25kg.
It's hard to guess if they are at upper or lower limit.
Lower improves Cog,
upper improves ES efficiency (this would be my guess).

On average a F1 Lithium ion battery pack is fully charged and discharged over 70 times during each GP. Energy flows in and out of the battery takes place in response to driver throttle and braking inputs.

You absolutely go for the upper limit, it's a no brainer. More cells means more headroom for discharge/charge rates.

subcritical71 wrote: ↑

12 Oct 2018, 13:03

A good recent article (http://www.powersourcesconference.com/P ... s/21-3.pdf) on Saft pouch type battery testing. Figure 1 shows the tradeoff between specific energy and power which may greatly effect battery performance. Of note is the last page in the article where it talks about solid state batteries. This could be (or maybe already is) technology F1 will adopt.

I don't know all the in's and out's of battery technology but by graphing out Figure 1 of the above pdf you can see the tradeoff the manufacturers can be faced with.

1) The chart is a bit busy, but solid lines would be battery weight of 25 kg, dashed lines is 20 kg.
2) Data points (x-axis): 1st - High Energy Cell, 2nd - Power Cell, 3rd - Very High Power Cell, 4th - Ultra High Power Cell
2) Looks like the best use scenario for the Saft battery is to use their Power Cell technology. This gives the following;
-20 kg battery can discharge 120 kW and have a total capacity of ~8.6 MJ
-25 kg battery can discharge 150 kW and have a total capacity of ~10.8 MJ
3) This has me thinking, could the suspected Ferrari dual battery have two types of cell technology. Maybe the Power Cell for the MGU-K where exactly 120 kW charge / discharge is needed, and another for the MGU-H which would be sized based on its use scenario?

Weight restrictions only take into account the cells and electrical connections), I'm not sure if Safts' figures include these extras:

5.4.3 The total weight of the part of the ES that stores energy, i.e. the cells (including any clamping plates) and electrical connections between cells, must be no less than 20kg and must not exceed 25kg.

saviour stivala wrote: ↑

12 Oct 2018, 19:16

On average a F1 Lithium ion battery pack is fully charged and discharged over 70 times during each GP...

No, it isn't...

godlameroso wrote: ↑

12 Oct 2018, 19:54

You absolutely go for the upper limit, it's a no brainer. More cells means more headroom for discharge/charge rates.

With only 2 ES per season I'd tend to agree. 25kg is the more likely number