Enjoyment of driving the Mk4 Jazz

[Jeff15]

The Jazz is an amazing piece of Engineering and technology.....

[richardfrost]

I've seen posts on this forum which seem to suggest that the use of the brake, going downhill or whatever, during the regeneration mode, adds to the effect and increases the charge in the HV battery.
No, I believe the exact opposite happens, since energy is used up by the brakes, leaving less available for regeneration.
It would be interesting to know, whether Time and/or Speed come into the equation, by that I mean whether going down a hill slower, hence taking longer, makes any difference?
In fact what are the optimum parameters, for extracting maximum charge, from a given regeneration situation?

Regenerative braking is what hybrids are all about. I think you are wrong.

[nowster]

Regenerative braking is what hybrids are all about. I think you are wrong.

I agree. There will be a braking force below which regeneration will be exclusively used if it is available.

The brake pedal in cars has had various assist devices for several decades, not least being ABS.

[Kenneve]

Regenerative braking is what hybrids are all about.

Hi Richard, Yes I accept what you say, I think I was trying say, that use of the brake pedal does not increase the regenerative braking, or the amount of charge obtained.
I suppose its true to say that the amount of regeneration charge, is simply determined by the steepness and length of the hill, or the severity of braking.

[sportse]

The battery pack is very small in the Jazz and fast charging, so it's easy to fill it up and then any regen beyond that is wasted unfortunately.

There is a 2km+ hill near me with a steep section to start in a 40mph zone, by the time I've not even gone half way the battery pack is already full.

[richardfrost]

Regenerative braking is what hybrids are all about.

I was trying say, that use of the brake pedal does not increase the regenerative braking, or the amount of charge obtained.

I can't speak for the Honda system, my Jazz is a 2005SE, but my Toyota absolutely regenerates more the harder you brake using either the pedal or the simulated gear changes. It is the only way it charges.

[John Ratsey]

There is a 2km+ hill near me with a steep section to start in a 40mph zone, by the time I've not even gone half way the battery pack is already full.

If it's a hill that you regularly visit then you can explore different driving techniques as you approach the hill with the objective of starting the descent with the battery at the low end of the charge range.

However, I agree that more battery capacity would be welcome, not only to accommodate more regeneration on longer descents but also pushing further into the future the time when battery wear starts to adversely affect the overall efficiency.

[Jazzik]

...but my Toyota absolutely regenerates more the harder you brake using either the pedal or the simulated gear changes. It is the only way it charges.

...and this means that there is either something completely wrong with your Toyota Hybrid, or you don't really understand how it works...
Watch this:

The battery is also charged by the generator, driven by the petrol engin!

[richardfrost]

...but my Toyota absolutely regenerates more the harder you brake using either the pedal or the simulated gear changes. It is the only way it charges.

...and this means that there is either something completely wrong with your Toyota Hybrid, or you don't really understand how it works...
Watch this:

The battery is also charged by the generator, driven by the petrol engin!

Should have said, regeneratively. Of course it charges by the engine. Fact is, it is so hilly where I live the engine charging doesn't happen that much in my normal use. E.g. today I shopped at a Farm Shop on the moors and drove the 5 miles home completely on electric and also totally filled the battery. No petrol was used at all.

[guest9814]

There is a 2km+ hill near me with a steep section to start in a 40mph zone, by the time I've not even gone half way the battery pack is already full.

If it's a hill that you regularly visit then you can explore different driving techniques as you approach the hill with the objective of starting the descent with the battery at the low end of the charge range.

However, I agree that more battery capacity would be welcome, not only to accommodate more regeneration on longer descents but also pushing further into the future the time when battery wear starts to adversely affect the overall efficiency.

There is enough space to put 1.8kw battery, as only half of spare tyre used by hybrid battery with all it's electronic staff.
By the way how big in kwh battery may by put in place of gasoline tank ?
If the battery by placed under seats and fuel tank in place of spare tyre we will get some alternative to BMW i3 REX 

[sportse]

Yes, assuming the development of cheap and fast charging battery packs, it would be very easy to bring out a full EV Jazz - just replacing the engine & fuel tank spaces with batteries.

There's also some more space in the boot underfloor, and if they really wanted to they could give up the magic seats and put more batteries under the rear seats too for a huge range.

[guest9814]

Yes, assuming the development of cheap and fast charging battery packs, it would be very easy to bring out a full EV Jazz - just replacing the engine & fuel tank spaces with batteries.

There's also some more space in the boot underfloor, and if they really wanted to they could give up the magic seats and put more batteries under the rear seats too for a huge range.

Honda played with Fit EV in USA in 2012

That FIT have 22kwh battery and 123hp electric motor

[John Ratsey]

There's also some more space in the boot underfloor, and if they really wanted to they could give up the magic seats and put more batteries under the rear seats too for a huge range.

Honda might not want to extend the battery further backwards but is keeping that underfloor cavity as part of the crumple zone. I reckon that the magic seats could be moved at least 2" forwards and still have excellent rear seat legroom while creating space for a slightly larger battery (and would increase boot capacity when the rear seats are up).

A 40 litre fuel tank is 100cm x 40cm x 10cm (or any other dimensions that give the same total) which I don't think is bigger than the current battery pack.

 A battery that gives good EV range might need to be built into the floor pan. The slab shape probably also helps with heat management.

[Kenneve]

Hi Guys
Today I reached the 5000 miles point on my Mk4, since purchase in April.
The attached photo shows the fuel consumption over that distance as 68.6 mpg, covering a wide variety of roads. narrow single track to motorways. This figure represents an improvement in consumption of around 25%, as compared with my previous Mk3 Jazz, which is probably just as well, given the current cost of fuel.

Do I still like the car? Yes, I still think it is the best Jazz yet and just a very nice place to be.

My only real concern, like so many others on this forum, are the so called safety gizmos and in particular the RDMS. Concerns expressed by other members, range for annoying to downright dangerous, I've mentioned before about the 'Hand of God' intervening on narrow country lanes and attempting to steer me into the path of an oncoming car. In my view the feature is totally unsuited to the vast majority of UK roads.

Do Honda actually read these posts. They really need to issue a software update, whereby the RDMS can be permanently disabled, at the discretion of the driver, much like LKAS. Having to disable it at every start-up is a real PITA.

Honda, please do something about it !!!!

[Kremmen]

Purchased in April and 68.6 is a good Summer mpg.

I bet that drops through Winter.