S-plus - Is it really 'fake'

[Liverfluke3]

And as a reminder, when considering this stuff, the battery in the Prelude is tiny compared to that in EVs and ‘range extender’ hybrids.
I have a little electric outboard motor with a 1kWh battery. That battery is about the same size and weight as a heavy duty conventional 12v car battery.

 

[Alfettaman109 1]

And as a reminder, when considering this stuff, the battery in the Prelude is tiny compared to that in EVs and ‘range extender’ hybrids.
I have a little electric outboard motor with a 1kWh battery. That battery is about the same size and weight as a heavy duty conventional 12v car battery.

The 1.1 kWh capacity is really the only thing it has in common with a conventional 12 V lead-acid accumulator.

72 lithium ion cells (instead of six lead-acid ones!), 260V, and capable of ultra high charge and discharge rates. It can also deep-cycle without any ill effect, so at least 85% of its theoretical capacity can be used routinely. In the UK, this HV battery is guaranteed to retain at least 70% of its 'as new' capacity for eight years.

 

[Liverfluke3]

The 1.1 kWh capacity is really the only thing it has in common with a conventional 12 V lead-acid accumulator.

72 lithium ion cells (instead of six lead-acid ones!), 260V, and capable of ultra high charge and discharge rates. It can also deep-cycle without any ill effect, so at least 85% of its theoretical capacity can be used routinely. In the UK, this HV battery is guaranteed to retain at least 70% of its 'as new' capacity for eight years.

Understood.

What I am really trying to say is that the battery is just a buffer between the ICE+generator and the traction motor.
It’s easy to think of the battery as the source of power and the ICE as there to charge the battery. I certainly saw it that way until I got some miles under my wheels.
But better, perhaps, to think of the ICE+genny as the source of power, with the battery as a buffer that fills in the gaps between traction demand and ICE delivery.

The battery and eCVT makes it possible for the ICE to run in Atkinson cycle, giving almost double the thermal efficiency of a conventional Otto cycle ICE.

 

[Alfettaman109 1]

Understood.

What I am really trying to say is that the battery is just a buffer between the ICE+generator and the traction motor.
It’s easy to think of the battery as the source of power and the ICE as there to charge the battery. I certainly saw it that way until I got some miles under my wheels.
But better, perhaps, to think of the ICE+genny as the source of power, with the battery as a buffer that fills in the gaps between traction demand and ICE delivery.

The battery and eCVT makes it possible for the ICE to run in Atkinson cycle, giving almost double the thermal efficiency of a conventional Otto cycle ICE.

Exactly right. Honda's hybrid system uses the HV battery as a way to temporarily dissociate power demand from power generation - allowing the use of a more efficient (Atkinson) generator, and delivering peak power that exceeds the maximum output of the ICE.

All of the power delivered ultimately comes from the fuel (gas) tank, but ironically the car is electrically propelled most of the time. And most of that electrical energy doesn't pass through the HV battery but is supplied directly to the electric propulsion motor.

 

[Alfettaman109 1]

To put the very modest size of our Prelude's HV battery into context.....

• 228 kg: the 35.5 kWh 335V lithium-ion battery in my fully-electric (and very small!) Honda e
• 36 kg: the 1.1 kWh 262V lithium-ion Prelude HV battery
• 19 kg: a typical 1 kWh 12V lead-acid conventional car battery

The long range battery pack for a Tesla can weigh over 750 kg, so I think the little battery in our 6G Prelude more than 'pulls its weight'!

 

[rexracer23 24]

Had to make some updates to my post for clarification, 200hp never happens because it literally can't. 184hp is the limit, 200hp is fantasy math that the regulations allow to sneak through.

Are you saying the Prelude is actually making les power than the 200hp advertised?

 

[PR76UDE108 49]

Are you saying the Prelude is actually making les power than the 200hp advertised?

Yes, it makes 184.

 

[rexracer23 24]

The 1.1 kWh capacity is really the only thing it has in common with a conventional 12 V lead-acid accumulator.

72 lithium ion cells (instead of six lead-acid ones!), 260V, and capable of ultra high charge and discharge rates. It can also deep-cycle without any ill effect, so at least 85% of its theoretical capacity can be used routinely. In the UK, this HV battery is guaranteed to retain at least 70% of its 'as new' capacity for eight years.

Does that mean performance and mpg drop?

 

[PR76UDE108 49]

Does that mean performance and mpg drop?

As the battery loses capacity you'll see a mild MPG drop, and eventually a lower  sustained performance. As in it'll more quickly have to back off on power. Neither of which I'd imagine will be really noticeable unless the battery has severely degraded.

 

[GoZoner72 71]

Out of curiosity, what happens if you just hold the paddle?

Mentioned in another thread (was it you?) the ‘gear’ drops down to the lowest possible. So, for example, if you are in 6th, holding the paddle will drop you to 3rd instantly. Said another way, holding the paddle gives you the maximum engine RPMs possible (while respecting the ‘gear’ to RPM mapping).

That is a great feature.

 

[rexracer23 24]

As the battery loses capacity you'll see a mild MPG drop, and eventually a lower  sustained performance. As in it'll more quickly have to back off on power. Neither of which I'd imagine will be really noticeable unless the battery has severely degraded.

I have not researched it. How is the Prelude’s hybrid technology been holding up in the Civic Hybrid? How long has the same Civic Hybrid technology been around and used?

 

[Alfettaman109 1]

I have not researched it. How is the Prelude’s hybrid technology been holding up in the Civic Hybrid? How long has the same Civic Hybrid technology been around and used?

Honda's first implementation of the iMMD hybrid system was in the 2019 Honda CR-V. I bought one of the very early ones, which I still own. Seven years on, The hybrid system still seems to work perfectly and I've not noticed any degradation of performance or economy - we can still achieve 55+ mpg [UK]....

 

[rexracer23 24]

Yes, it makes 184.

I have no idea of how hybrids are calibrated or rated. Thanks for the information.

 

[PR76UDE108 49]

I have no idea of how hybrids are calibrated or rated. Thanks for the information.

I think it's just down to the American measurement system not being designed with series hybrids in mind. Though the system Europe uses isn't without its flaws either as it potentially does under-report the power of hybrids.

I have not researched it. How is the Prelude’s hybrid technology been holding up in the Civic Hybrid? How long has the same Civic Hybrid technology been around and used?

I've not done a ton of research into it either but I wouldn't be worried. I believe the drivetrain is about 5 years old now, and is based on some sound engineering. Likely not cycling the battery beyond 30% on the low end and 80-90% on the top end so it's not particularly strained, and it lives within the cabin technically so has reasonable temperature management. I wouldn't really start worrying about it til the car is ~10 years old, and even then it shouldn't be a problem nor too expensive to replace if it had started to fail given there's millions of cars build with the same hardware.

 

[GoZoner72 71]

Interesting to compare with this video from a 2025 European press event:

That really is a superb video/presentation.

 

[SSV85]

Agree - very good presentation which I've only just watched. Interesting that fuel economy in S+ appears to better in GT mode than Comfort according to the slide from 15min 54 secs

 

[nyon45 3]

Agree - very good presentation which I've only just watched. Interesting that fuel economy in S+ appears to better in GT mode than Comfort according to the slide from 15min 54 secs

What would make it such that Comfort would get fewer mpg than GT, S+ or not? I drive almost entirely Comfort and my MPG’s are low for this car.