## State of Charge - 4MJ

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
BassVirolla
BassVirolla
2
Joined: Fri Jul 20, 2018 10:55 pm

### State of Charge - 4MJ

Hi,

Under the discussions taken in the Ferrari PU Topic, a question arised to my mind:

What does State Of Charge (SOC) means exactly?

Could the teams deploy more than 4MJ per lap as long as they can recover more than 4MJ per lap? (via MGUH -> ES or "extra harvest" MGUK -> MGUH -> ES)

For example lets start with a full charged battery, where C = charge and D = Deploy:

SOC: 4MJ
D: -2MJ
SOC: 2MJ
C: +2MJ
SOC: 4MJ
D: -4MJ
SOC: 0MJ

Total discharge: 6MJ. While SOC always remained between 0 and 4 MJ.

Is this allowed? Could it be possible and / or useful?

turbof1
Moderator
Joined: Thu Jul 19, 2012 8:36 pm
Location: MountDoom CFD Matrix

### Re: State of Charge - 4MJ

BassVirolla wrote:
Wed Jul 25, 2018 10:59 am
Hi,

Under the discussions taken in the Ferrari PU Topic, a question arised to my mind:

What does State Of Charge (SOC) means exactly?

Could the teams deploy more than 4MJ per lap as long as they can recover more than 4MJ per lap? (via MGUH -> ES or "extra harvest" MGUK -> MGUH -> ES)

For example lets start with a full charged battery, where C = charge and D = Deploy:

SOC: 4MJ
D: -2MJ
SOC: 2MJ
C: +2MJ
SOC: 4MJ
D: -4MJ
SOC: 0MJ

Total discharge: 6MJ. While SOC always remained between 0 and 4 MJ.

Is this allowed? Could it be possible and / or useful?
State of charge refers to the difference between the lowest charge and the highest charge on your Energy Store. Compare it a fuel tank which is filled with joules. Say your Energy Store tank capacity is 16 MJ and you start the race with 12MJ. The difference between the maximum and minimum charge can only be 4MJ across the entire race, but thath difference can be something like
-minimum 8MJ and maximum 12MJ
-minimum 12MJ and maximum 16MJ
-minimum 10MJ and maximum 14MJ
-...

This is no way a limitation on its own how much energy you deploy on a lap. It only forces you to consume energy before reaching a net 4MJ or store energy when your consumption is about to dip 4MJ below the maximum. For instance if you generate 2MJ 6x a lap and you consume 2MJ 6x a lap inbetween your generation points, you effectively generated and consumed 12MJ that lap (this is hypothetical and nowhere near a reflection of how much energy is generated and stored real life).

So yes, you got the correct interpretation of it.

The question that arises: is it even profitable to have more ES capacity than 4MJ? Pure performance wise it isn't in theory. However, ES have to do roughly 10 races. Since its needs at minimum 20kg of weight, it is beneficial in terms of reliability to have extra but unused capacity just in case energy cells break down, without weight or CoG drawbacks.
#AeroFrodo

BassVirolla
BassVirolla
2
Joined: Fri Jul 20, 2018 10:55 pm

### Re: State of Charge - 4MJ

Thank you very much.

So we can assume the full story of the 120kw - 33s (or whatever proportion; double time is half power) is total misinformation since the day the technical regulations were revealed.

I was suspecting it for a long time. Thank you another time.

turbof1
Moderator
Joined: Thu Jul 19, 2012 8:36 pm
Location: MountDoom CFD Matrix

### Re: State of Charge - 4MJ

BassVirolla wrote:
Wed Jul 25, 2018 1:02 pm
Thank you very much.

So we can assume the full story of the 120kw - 33s (or whatever proportion; double time is half power) is total misinformation since the day the technical regulations were revealed.

I was suspecting it for a long time. Thank you another time.
Yes. 4MJ is 120kw for 33.33s, but even if the ES was only allowed to supply 4MJ across one lap, people forget the MGU-H can immediately put generated energy onto the MGU-K for deployment on the driveshaft, resulting in a longer period of 120kw of power.
#AeroFrodo

AJI
AJI
38
Joined: Tue Dec 22, 2015 8:08 am

### Re: State of Charge - 4MJ

BassVirolla wrote:
Wed Jul 25, 2018 1:02 pm

So we can assume the full story of the 120kw - 33s (or whatever proportion; double time is half power) is total misinformation since the day the technical regulations were revealed.
It wasn't really misinformation, it was more an over simplification (mainly by F1 commentators and ex-drivers), and as turbo said, it doesn't take direct H-K transfer into account.
IMO, the 120kW for 33.333 thing is just a hangover from pre-2014 when it really was a maximum of 60kW for 6.666 seconds per lap.

Sevach
Sevach
856
Joined: Thu Jun 07, 2012 4:00 pm

### Re: State of Charge - 4MJ

The 160 hp for 33s was the press needing to put a number that the average joe could understand.

Even forgetting the MGUH factor cars have highly complex deployment strategies, gear, speed and even timing/sequencing dependent(last year Alonso "broke" his car programming by going full throttle into Pouhon).
Aka you don't need full power in 2nd you'll just waste it spinning the tires.

Why the Mercedes pr department still uses the 33s figure?
Because there's no limit to the MGUH, it's not in their best interests to reveal just how effective their system is.

Even keeping their cards close to their chest you can see little tidbits of truth when a real tech guy speaks.
Here's Andy Cowell
https://www.autosport.com/f1/news/13594 ... --mercedes

60% of the energy used comes from the MGUH(which might be underselling it) and the Ferrari system is suppousedly better than that.

BassVirolla
BassVirolla
2
Joined: Fri Jul 20, 2018 10:55 pm

### Re: State of Charge - 4MJ

If 60% comes from MGUH, and we suppose that the MGUK is able to recover the full 2MJ allowed, this leaves an amount of 5MJ per lap.

This enforces the fact that the "33,3s thing" has no sense.

And, as you well say, improbably Mercedes is revealing al the truth and numbers. Possibly my initial example of 6MJ deployed in a lap is not too optimistic (in qualy mode?).

Sevach
Sevach
856
Joined: Thu Jun 07, 2012 4:00 pm

### Re: State of Charge - 4MJ

BassVirolla wrote:
Thu Jul 26, 2018 8:41 am
If 60% comes from MGUH, and we suppose that the MGUK is able to recover the full 2MJ allowed, this leaves an amount of 5MJ per lap.

This enforces the fact that the "33,3s thing" has no sense.

And, as you well say, improbably Mercedes is revealing al the truth and numbers. Possibly my initial example of 6MJ deployed in a lap is not too optimistic (in qualy mode?).
If they indeed can harvest 3MJ through the H that's conservative even.

Tzk
Tzk
24
Joined: Sat Jul 28, 2018 11:49 am

### Re: State of Charge - 4MJ

turbof1 wrote:
The question that arises: is it even profitable to have more ES capacity than 4MJ? Pure performance wise it isn't in theory. However, ES have to do roughly 10 races. Since its needs at minimum 20kg of weight, it is beneficial in terms of reliability to have extra but unused capacity just in case energy cells break down, without weight or CoG drawbacks.
Yes, it‘s profitable to have more than 4mj capacity. LiFe, LiIon and LiPo batteries can get charged fastest between ~20 to ~85% charge. They also tend to last longer (regarding capacity and number of charge/discharge cycles). You also want to avoid changing the complete ers due to a single dead cell.

If i had to build an ERS, i‘d try to stick as many cells into it as possible while sticking to the minimum weight as close as possible. So 20kg, maximum capacity.

gruntguru
gruntguru
455
Joined: Sat Feb 21, 2009 6:43 am

### Re: State of Charge - 4MJ

BassVirolla wrote:
Wed Jul 25, 2018 1:02 pm
So we can assume the full story of the 120kw - 33s (or whatever proportion; double time is half power) is total misinformation since the day the technical regulations were revealed.
Not at all. The ES can only send a maximum of 4 MJ/lap to the K and that is the origin of the 120 kW - 33s example.
je suis charlie

saviour stivala
saviour stivala
-18
Joined: Wed Apr 25, 2018 11:54 am

### Re: State of Charge - 4MJ

The ERS-K is the only element of the ERS system that is allowed to transfer electrical power to the crankshaft (the electrical engine of the hybrid power unit). What goes out of it to the crankshaft is limited to 120KW.
The ERS ES is the only energy store (battery) of the ERS system where harvested electrical energy can be stored, only 4MJ of harvested electrical energy can be stored inside it, and only 4MJ electrical energy can be deployed/discharged from it.
With all respect to all on here, but I just cannot understand why bigger numbers deployed than those stipulated by the rules/regulation are still in this fifth year of the ERS system being pushed out by some.

saviour stivala
saviour stivala
-18
Joined: Wed Apr 25, 2018 11:54 am

### Re: State of Charge - 4MJ

turbof1 wrote:
Wed Jul 25, 2018 12:57 pm
BassVirolla wrote:
Wed Jul 25, 2018 10:59 am
Hi,

Under the discussions taken in the Ferrari PU Topic, a question arised to my mind:

What does State Of Charge (SOC) means exactly?

Could the teams deploy more than 4MJ per lap as long as they can recover more than 4MJ per lap? (via MGUH -> ES or "extra harvest" MGUK -> MGUH -> ES)

For example lets start with a full charged battery, where C = charge and D = Deploy:

SOC: 4MJ
D: -2MJ
SOC: 2MJ
C: +2MJ
SOC: 4MJ
D: -4MJ
SOC: 0MJ

Total discharge: 6MJ. While SOC always remained between 0 and 4 MJ.

Is this allowed? Could it be possible and / or useful?
State of charge refers to the difference between the lowest charge and the highest charge on your Energy Store. Compare it a fuel tank which is filled with joules. Say your Energy Store tank capacity is 16 MJ and you start the race with 12MJ. The difference between the maximum and minimum charge can only be 4MJ across the entire race, but thath difference can be something like
-minimum 8MJ and maximum 12MJ
-minimum 12MJ and maximum 16MJ
-minimum 10MJ and maximum 14MJ
-...

This is no way a limitation on its own how much energy you deploy on a lap. It only forces you to consume energy before reaching a net 4MJ or store energy when your consumption is about to dip 4MJ below the maximum. For instance if you generate 2MJ 6x a lap and you consume 2MJ 6x a lap inbetween your generation points, you effectively generated and consumed 12MJ that lap (this is hypothetical and nowhere near a reflection of how much energy is generated and stored real life).

So yes, you got the correct interpretation of it.

The question that arises: is it even profitable to have more ES capacity than 4MJ? Pure performance wise it isn't in theory. However, ES have to do roughly 10 races. Since its needs at minimum 20kg of weight, it is beneficial in terms of reliability to have extra but unused capacity just in case energy cells break down, without weight or CoG drawbacks.
Technically speaking it is even regarded as dangerous to rapidly discharge/charge a battery more than 50% of its energy capacity.

seventhsin
16
Joined: Sun Jan 20, 2013 11:53 am

### Re: State of Charge - 4MJ

saviour stivala wrote:The ERS-K is the only element of the ERS system that is allowed to transfer electrical power to the crankshaft (the electrical engine of the hybrid power unit). What goes out of it to the crankshaft is limited to 120KW.
The ERS ES is the only energy store (battery) of the ERS system where harvested electrical energy can be stored, only 4MJ of harvested electrical energy can be stored inside it, and only 4MJ electrical energy can be deployed/discharged from it.
With all respect to all on here, but I just cannot understand why bigger numbers deployed than those stipulated by the rules/regulation are still in this fifth year of the ERS system being pushed out by some.
Incorrect. On many levels, again.

The component is the MGU-K, not ERS-K.

The ES is the most obvious place to store harvested energy however it's highly likely the teams are using other forms of brief storage as detailed in the Honda and Ferrari PU threads.

The ES can and almost certainly does store more than 4MJ. It's the State of Charge which cannot fluctuate more than 4MJ from minimum to maximum at any time the car is on track. This is different to MJ deployment per lap.

Finally for the umpteenth time, the ES is not limited to 4MJ per lap deployment.
.
Only deployment DIRECTLY from the ES to MGU-K is capped at 4MJ per lap.
AS stated countless times to you, the ES, MGU-K and MGU-H can deploy unlimited amounts of MJ between each other BEYOND the 4MJ cap that the ES sent directly to MGU-K. You can see this flow chart on many threads of this forum, or find it at the end of the F1 regulations. Perhaps the visual flow chart will help you understand.
As long as the State of Charge of the ES doesn't vary by more than 4MJ, everything above is all legal.

Your posts containing fallacious information have and will continue to be reported.
Your ignorance and erroneous statements have been polluting this forum for too long.
This site is of great value to those seeking to expand their knowledge of this fascinating sport, but knowledge takes twice as much reading and listening as it does speaking.

Sent from my SM-G950F using Tapatalk

gruntguru
gruntguru
455
Joined: Sat Feb 21, 2009 6:43 am

### Re: State of Charge - 4MJ

saviour stivala wrote:
Mon Jul 30, 2018 12:27 pm
The ERS ES is the only energy store (battery) of the ERS system where harvested electrical energy can be stored, only 4MJ of harvested electrical energy can be stored inside it, and only 4MJ electrical energy can be deployed/discharged from it.
With all respect to all on here, but I just cannot understand why bigger numbers deployed than those stipulated by the rules/regulation are still in this fifth year of the ERS system being pushed out by some.
Lets look at ES>H and H>ES because those paths are unlimited in terms of both power and energy.

Suppose the ES is at the bottom of its 4MJ SOC band.
Suppose during some period of reduced power, a lot of excess energy can be harvested from the H and 4MJ is transferred to the ES. The ES is now at the top of its SOC band so no further energy can be harvested.
Suppose the car rounds a corner and accelerates into another long straight. Electric supercharger mode is activated and 4MJ of energy is sent from the ES to the K. The ES is now at the bottom of its SOC band so no further energy can be deployed.
Suppose the last section of the straight is a good place to harvest and another 4MJ goes from H>ES. (Can you see where this is going).
Suppose there are 10 sections on the track where this cycle can be repeated. You have a total of 40MJ harvested and deployed in one lap.

OK, so the numbers are ridiculous but can you see that the rules do not limit the per-lap energy flow to the ES?
je suis charlie

saviour stivala
saviour stivala
-18
Joined: Wed Apr 25, 2018 11:54 am

### Re: State of Charge - 4MJ

I can see and fully understand your reasoning and thanks for trying to explain but am sorry I cannot agree with all that.