F1 Energy store density for 2026 and hot swap batteries

[wuzak]

Yes of course additional power can be fed from the MGU-H to the MGU-K. But while it can compensate for lack of ES stored output, it cannot 'AXTEND', and by that I mean, 'ADD', to the maximum MGU-K output deployment per lap by the rules.

The rule specifically states a maximum of 4MJ can be deployed from the ES to the MGUK, 2MJ can be recovered from the MGUK to the ES, and unlimited energy can be transferred from the MGUH to the MGUK.

So the limit would only be 4MJ if the MGUH couldn't recover more than 2MJ, the difference between maximum MGUK-ES recovery and ES-MGUK deployment.

A note. You certainly have a very low opinion of the higher end technical people involved in F1.

First case: RBPT engineer, head of ICE development clearly has expertise in his field. His field, however, was not, at the time of recording at least, ERS or its integration and race usage.

It would be interesting to ask him on this point again, to see if he still believes that it will not be allowed to charge the battery using the ICE.

Second case: I was talking about journalist covering F1, most of whom or not that technically minded. Taffin was giving an explanation that could be understood by most people, but may not have reflected how the MGUK is used in reality.

[wuzak]

''History repeating itself'' At introduction of the present PU formula after it had been agreed upon by all concerned, and outed specification of its mandated ERS, Very few if any outside of those agreed to the new formula, and that includes most people from on here, could figure-out or see how was the new mandated ERS going to sustain ERS deployment for any reasonable length of time around a lap. It didn't took a long time for teams to come out claiming that they could deploy mostly all around a lap. And all this was achieved with the power unit formula devised/designed around the capturing of two different heat energy source that in the previous formula went to waste, namely braking heat (rear wheels only) and exhaust gas heat. What confused most if not all, were the permitted recovery by brakes and ES maximum capacity plus the MGU-K maximum permitted deployment time per lap. We are now going exactly through the same doubtful and conjecture/speculative process, even when experts involved comes out from time to time and say "this or that will not be permitted". because of our lack of knowhow and so build-in doubt, we promptly pronounce the lack of technical knowledge of said experts.

The rules state:
9MJ of energy can be recovered by the MGUK per lap at a maximum of 350kW.
MGUK energy deployment is unlimited.
4MJ can be stored at any one time.
When maximum torque is demanded by the driver the power output can be reduced by 100kW per second, up to a maximum of 450kW.

What can we infer from these rules.
The track with the most braking time is Singapore, with about 25s. If all that braking is hard enough for the rear wheels to recover at 350kW, that means approximately 7.5MJ could be recovered in a lap.

So either there is another way of recovering energy, or the rules are stupid.

What of this power reduction rule? Why does it allow the power to be reduced more than the power of the MGUK?

Could it be that it is allowing the recovery of energy when the driver is at full throttle?

[Tommy Cookers]

'And all this was achieved with the power unit formula devised/designed around the capturing of two different heat energy source that in the previous formula went to waste, namely braking heat (rear wheels only) and exhaust gas heat.

What confused most if not all, were the permitted recovery by brakes and ES maximum capacity plus the MGU-K maximum permitted deployment time per lap.

you and your (imaginatively translated ?) friend Taffin are mistaken

this is not a class in moral philosophy
there is no capturing of braking heat

and there is no MGU-K maximum permitted deployment time per lap

[diffuser]

Everyone is going to be roughly the same in the end and optimum deployment locations for limited reserve will be dictated by computer simulations.

My point was, without being able to drive the MGU-K with the ICE, you're gonna only have slightly more than 11seconds of deployment. The car might be faster without having to carry around the battery and MGU-K.

For 2026 the deployment is unlimited.

However, energy recovery allowed is 9MJ maximum, while storage is 4MJ maximum.

If 9MJ can be recovered, then 25.7s of deployment at 350kW would be possible, and maybe 37.1s is possible for qualifying (4MJ storage + 9MJ recovery).

It is likely that the full power usage is much more limited than that, and the bulk of the deployment would be 150-200kW.

One of the reasons for this is that the deployed power is reduced at 5kW per km/h over 300km/h, up to 340km/h, where the output limit is 150kW.

9MJ per lap?

These ICEs idle at 5K prm. That MGU-K could regenerate alot of power just at Idle.

[saviour stivala]

As I said, history is repeating itself. speculations/assumptions/plus gloom and doom left right and center. "could it be that that it is allowing the recovery of energy when the driver is at full throttle?''. Apart from this question being asked right after assuring one and all that rules says nothing against recovering under power, This means recovery when ICE is under power. I know that I have been told that the RBPT power unit project leading engineer does not know/understands the new for 2026 ERS rules, but I personally still believe in his rejection of the above mentioned recovery possibility when he said not possible to harvest under ICE power, as that possibility is a no-go as things stays as are at present, meaning even at present that possibility of MGU-K recovering under ICE power is not allowed.

[wuzak]

My point was, without being able to drive the MGU-K with the ICE, you're gonna only have slightly more than 11seconds of deployment. The car might be faster without having to carry around the battery and MGU-K.

For 2026 the deployment is unlimited.

However, energy recovery allowed is 9MJ maximum, while storage is 4MJ maximum.

If 9MJ can be recovered, then 25.7s of deployment at 350kW would be possible, and maybe 37.1s is possible for qualifying (4MJ storage + 9MJ recovery).

It is likely that the full power usage is much more limited than that, and the bulk of the deployment would be 150-200kW.

One of the reasons for this is that the deployed power is reduced at 5kW per km/h over 300km/h, up to 340km/h, where the output limit is 150kW.

9MJ per lap?

These ICEs idle at 5K prm. That MGU-K could regenerate alot of power just at Idle.

But how much power do they make at idle?

[saviour stivala]

"But how much power do they make at idle?" I say Not enough to even move the car off the line, trying to move the car off the line at idle the power unite will in most probability stall. And I am not quoting any expert directly involved, to eliminate the possibility of branding such people directly in the know as not knowledgeable by other experts commenting on here.

[wuzak]

The Mercedes AMG One gives a little insight into the current rules.

It has a development of 2015 F1 engine. It has an MGUH rated at 90kW (122hp).

Whether it can recover at that power is unknown.

Let's say for F1 that the recovery power is half, or 45kW.

At Spa, for an extreme example, the cars are at full throttle for 82% of a lap, which is roughly 105s long.

If we say that the MGUH can recover at full potential for 70% lap, we have:

70% x 105s = 73.5s.

73.5s x 45kW = 3.31MJ.

Presuming that the MGUK can recover the allowed 2MJ back to the battery, that means that the total energy recovered is 5.3MJ, which would allow full power to the MGUK for 44s.

[diffuser]

"But how much power do they make at idle?" I say Not enough to even move the car off the line, trying to move the car off the line at idle the power unite will in most probability stall. And I am not quoting any expert directly involved, to eliminate the possibility of branding such people directly in the know as not knowledgeable by other experts commenting on here.

Doesn't really matter does it? You could adjust the duration or whatever to generate more power at idle...or even raise the idle speed.

I guess at the end of the day, it comes down to whether you burn more fuel energy than you generate in electrical.

[Hoffman900]

The Mercedes AMG One gives a little insight into the current rules.

It has a development of 2015 F1 engine. It has an MGUH rated at 90kW (122hp).

Whether it can recover at that power is unknown.

Let's say for F1 that the recovery power is half, or 45kW.

At Spa, for an extreme example, the cars are at full throttle for 82% of a lap, which is roughly 105s long.

If we say that the MGUH can recover at full potential for 70% lap, we have:

70% x 105s = 73.5s.

73.5s x 45kW = 3.31MJ.

Presuming that the MGUK can recover the allowed 2MJ back to the battery, that means that the total energy recovered is 5.3MJ, which would allow full power to the MGUK for 44s.

I think this paper does a much better job:

This paper is co-authored with Ferrari. Published in 2021. The authors also have other papers concerning aspects of the F1 hybrid PU’s.

https://www.mdpi.com/1996-1073/14/1/171

Abstract:
“Today, Formula 1 race cars are equipped with complex hybrid electric powertrains that display significant cross-couplings between the internal combustion engine and the electrical energy recovery system. Given that a large number of these phenomena are strongly engine-speed dependent, not only the energy management but also the gearshift strategy significantly influence the achievable lap time for a given fuel and battery budget. Therefore, in this paper we propose a detailed low-level mathematical model of the Formula 1 powertrain suited for numerical optimization, and solve the time-optimal control problem in a computationally efficient way. First, we describe the powertrain dynamics by means of first principle modeling approaches and neural network techniques, with a strong focus on the low-level actuation of the internal combustion engine and its coupling with the energy recovery system. Next, we relax the integer decision variable related to the gearbox by applying outer convexification and solve the resulting optimization problem. Our results show that the energy consumption budgets not only influence the fuel mass flow and electric boosting operation, but also the gearshift strategy and the low-level engine operation, e.g., the intake manifold pressure evolution, the air-to-fuel ratio or the turbine waste-gate position.”

[wuzak]

"But how much power do they make at idle?" I say Not enough to even move the car off the line, trying to move the car off the line at idle the power unite will in most probability stall. And I am not quoting any expert directly involved, to eliminate the possibility of branding such people directly in the know as not knowledgeable by other experts commenting on here.

Doesn't really matter does it? You could adjust the duration or whatever to generate more power at idle...or even raise the idle speed.

I guess at the end of the day, it comes down to whether you burn more fuel energy than you generate in electrical.

If you load the engine with the MGUK to generate a useful amount of energy, the engine isn't really at idle, even if it is at nominal idle speed.

[saviour stivala]

'And all this was achieved with the power unit formula devised/designed around the capturing of two different heat energy source that in the previous formula went to waste, namely braking heat (rear wheels only) and exhaust gas heat.

What confused most if not all, were the permitted recovery by brakes and ES maximum capacity plus the MGU-K maximum permitted deployment time per lap.

you and your (imaginatively translated ?) friend Taffin are mistaken

this is not a class in moral philosophy
there is no capturing of braking heat

and there is no MGU-K maximum permitted deployment time per lap

ERS comprises two motor generator units "K" and "H" that both convert mechanical and heat energy to electrical energy and vice versa. While the "K" that stands for motor/generator kinetic, have it's recovery limited to 2mj per lap, when acting in motor mode (deploying) it provides an additional 161hp to the crankshaft that can be used for33.33 seconds per lap.

[saviour stivala]

"But how much power do they make at idle?" I say Not enough to even move the car off the line, trying to move the car off the line at idle the power unite will in most probability stall. And I am not quoting any expert directly involved, to eliminate the possibility of branding such people directly in the know as not knowledgeable by other experts commenting on here.

Doesn't really matter does it? You could adjust the duration or whatever to generate more power at idle...or even raise the idle speed.

I guess at the end of the day, it comes down to whether you burn more fuel energy than you generate in electrical.

If you load the engine with the MGUK to generate a useful amount of energy, the engine isn't really at idle, even if it is at nominal idle speed.

When the engine is at "IDLE" the engine cannot be "loaded with the MGU-K to generate any amount of energy, because when the engine is at ''IDLE'' the car is not moving. Fertile imagination at its best.

[Tommy Cookers]

... ERS comprises two motor generator units "K" and "H" that both convert mechanical and heat energy to electrical energy and vice versa.

the present F1 rules assume 95% efficiency conversions between mechanical work and electricity and vice-versa so .....
the K system converts electricity 95% into mechanical work (useful) and 5% into losses eg heat and ....
converts mechanical work eg braking 95% into electrical work (useful) and 5% into losses eg heat

[saviour stivala]

As MGU-K recovers energy when braking. When driver steps on the brake pedal, the discs and the brake pads create friction as they meet, in turn friction creates kinetic energy that dissipates into environment in the form of heat.