Hybrid battery fail.

[Neil Ives]

The engine will cut in and out as needed to keep both batteries charged

Ah, I'm glad you mentioned this. In a normal car I would always use Aux mode in a similar situation to save the ignition coil from overheating. I would like to know if the ignition is disabled in the MK4 Jazz when the engine is stopped during normal running. I guess it must be.

[coldstart]

... to save the ignition coil from overheating ...

What exactly makes you think the ignition coil would be overheating?

And if it was actually a problem: I would assume Honda's engineers would have thought about it?
(it's not their first car they are bulding)

After all: Non-accessory-mode is the normal  operating state of our Jazzes!

[Neil Ives]

... to save the ignition coil from overheating ...

What exactly makes you think the ignition coil  :-Xwould be overheating?

And if it was actually a problem: I would assume Honda's engineers would have thought about it?
(it's not their first car they are bulding)

After all: Non-accessory-mode is the normal  operating state of our Jazzes!

Will you read my text again please

[aphybrid]

From Lord Voltomore - "It might be possible to  replace the HV battery for not much more than a replacment clutch.Something the Jazz  Mk4 wont need replacing  because it doesnt have one."

There are two clutches in the system as explained by Prof Kelly in Weber State University Davis Youtube video, one is emergency breakaway but the other works every time via oil pressure when ICE only mode starts as I understand it.
since neither are subject to the vagaries of driver operation probably are designed lifetime of the system, whatever that is.

[Kremmen]

When I first got mine I knew the batteries would not be fully charged

As I also knew I'd be spending about an hour setting things up so I just left it in EV mode and let the engine kick in every now and again as I was draining it doing my initial setup

[Lincolnshire Rambler]

It could be interesting to see if the modest size of the HV battery -around 1kW and 200volts is (similar to toyotas HEV) due to how fast the charge is put in and taken out . Watching the power flow graphics it can switch quickly from putting the charge in to taking it out ..and then back again -is this need better provided by a smaller battery or isnt it relevent to the battery capacity. Unlike an EV most of tbe energy is flowing out between plug in charges with top ups from regen braking and they need bigger capacity for range ?

[ahavoja]

In reply to Lincolnshire Rambler:
In electrical way, a bigger battery would be slightly better (but not much), because all those charges and discharges would feel smaller, and happen at a slower rate compared to its big capacity, like lifting something heavy feels lighter and easier for a strong person.

However, a bigger battery also costs more, weighs more and reduces the boot space even more, so maybe Honda engineers thought that a bigger battery isn't worth those tradeoffs. The battery of Jazz doesn't need to have a large capacity like in an EV, because the petrol engine can charge it anytime when needed.