Failed to start... again

[Jazzik]

Yes, all except the SE. From page 41: https://brochures.honda.co.uk/cars/jazz-hybrid/?page=42

[embee]

I have heard that  'connected' cars  do consume more battery power  when parked due to their communicating with stuff.  Not much, but it all adds up over time.  I wonder if activating the Honda +  bag of tricks  ,increases the load significantly .

Not strictly related to this, but it can certainly be tricky to determine the "quiescent" current drain on modern cars because of the things they do. I had need to try to find out why someone's Hyundai battery kept going flat in relatively short periods of standing idle.
In older cars the current drain was easy to measure, just fit an ammeter between the battery and earth and see what it was reading. On the Hyundai I noted that the current would vary significantly for quite a long period after switching everything off. Clearly the car systems were doing things "behind the scenes".
Eventually that was a simple fix, the owner had previously had an insurance "black box" fitted, though no longer used that insurance method, but the box was still plugged in and powered. Unplug it, check everything still worked, fit new battery and all was well.
Are modern cars a bit too clever for their own good? Maybe .......

[Lord Voltermore]

Perimeter alarm. Really?

Not the correct terminology. Poster is referring to an alarm that detects movement inside the car. The normal way to break into a vehicle is to smash a window, open a door and get in. Honda alarm goes off on the door opening . If a thief smashed a window and reaches in the alarm doesn't go off. Good alarm systems detect movement inside the car and would sound when a window is smashed and or a hand thrust inside.

Fancy alarms  can be more trouble than they are worth. I once had a professionally fitted alarm that could detect a broken window and movement of the car. It was a pita. It would go off in  a high wind, heavy rain, passing lorry, and a granny who leaned on the car nearly had a heart attack when the alarm went off.  (gangsta granny ?) I couldnt get the sensitivity calibration just right.   And back then false alarms were so common folk tended to ignore them, and Starlings imitated them. (I wonder how many starlings  never got born because their potential mothers rejected their father in favour of a Ford Escort     ) And to cap it all  it regularly flattened the car battery.   

Crooks doing  a smash and grab for something in the car would do it anyway, and leg it.  The damage already done.  Might as well wait until they open a door.     They might carry on anyway  - Cat converter thieves dont seem to care if they are spotted.   

[Lord Voltermore]

Just checked my EX. The battery was  showing  11.8 Volts  .   Last driven on 15 October  (and that was a very long journey.)   But about a week ago I had it powered up for about 20 minutes on the driveway  which pumped in 14.4 volts and will have  topped it up a bit.   Plan to drive it on tuesday.    (I have the use of another car at the moment so no sense adding unnecessary  miles to the Jazz.  ) 

[Jazzik]

no sense adding unnecessary  miles to the Jazz.  )

What about adding unnecessary Volts?

[Lord Voltermore]

no sense adding unnecessary  miles to the Jazz.  )

What about adding unnecessary Volts?

Voltermore likes more volts.   Unlike my twin Brother Lord Revolt-her-more, whos is not as popular as me with the Ladies.   

[John Ratsey]

Has anyone with a 12V battery problem tried disconnecting and reconnecting the battery? This should get the car to think there's a new battery which needs to be properly charged. Disconnect / reconnect was one way to fix the autostop not working in the Mk 3 Jazz due to low battery. One cause of this was that the car, aided and abetted by the intelligent battery sensor, wasn't putting enough charge into the battery because it reckoned the battery was well charged already and adding unneccessary extra charge was wasting energy. Does the Mk 4 Jazz a similar problem?

[5thcivic]

My old Civic battery went dead when I was in hospital with Covid in 2019. After charging up, the car started but only half the displays were working. I disconnected the battery and connected again but it was the same. Rang the dealer service dept, described the symptoms and they advised straight away to leave the battery disconnected for at least 15 minutes for all the internal caps to discharge completely for a full reboot. Did that and problem solved. Worth bearing in mind for a similar situation.

[FMIB]

Without knowing the exact battery charging mechanics of a hybrid whilst running, I can imagine that lots of short journeys around town when the car spends significant time in EV mode or with the engine running at low revs, can have a significant drain on the battery.
Whilst running in EV mode, I assume many of the cars auxiliary components(12V) will need to run off the battery as the voltage from the traction battery is too high, same as full EV cars. When the engine chimes in, it will tend to be at lower revs most of the time compared to a convention ICE and hence there is likely to be less continuous charge from, I assume the generator(or separate alternator?), to charge the battery.
Just my thoughts as why the battery is often reading low voltages.

Questions for current owners, if you power the car on and its in EV mode and sit in it stationary, how long before the engine starts up? If you do the same, switch on the radio, headlights,  heated seats etc, one by one, does the engine fire up quicker?

[Kremmen]

If you powerup and turn on the heater when it's colder inside than the temp set then the engine does fire up almost immediately.

My routine is to turn off the heater/aircon when I powerup in the garage then turn it on at the end of the street.

[Lord Voltermore]

My understanding is when the engine is running  its generator  charges up the HV battery.   When the Hv battery needs charging the I.C.E engine starts  .  When it doesnt need to be charged the  engine stops and the car is in EV mode.
The engine driven generator  (or whatever regenerative braking generation is available )  does not charge the 12v battery directly.  This receives   its charge   from the HV battery   which gives it a charge of up to 14.4 volts or so, regardless of whether the engine is running or not.  Or in other words its charged by another battery, rather than an engine driven alternator as in a conventional car  (which also typically charge at 14.4 volts)

If the demand from 12v systems in the car is higher  the 12v battery needs to draw more power from the HV battery  , Its the need to keep the HV battery topped up that indirectly causes the engine to start  sooner and for longer ..  Its not to directly charge the 12v Battery.     

Sorry , I gave up long ago trying to predict when the engine will start and when it wont .  Its smart, and seems to defy logic.  it will often start when there are plenty of charge bars on the HV battery.
In warm weather  on first powering up you may be able to drive off without the engine starting at all   until a mile or so into your journey.    But if you have air con on it seems to predict power will be needed soon and the engine almost always starts up immediately, even if the HV battery is more or less fully charged.   

The HV battery charges up very quickly.  But the 12v battery is a conventional lead acid battery that takes longer.  Short and infrequent journeys dont give a long enough time for the HV battery to fully charge it.   

[Kremmen]

Yep, that's how I see it and how mine seems to perform

[FMIB]

My understanding is when the engine is running  its generator  charges up the HV battery.   When the Hv battery needs charging the I.C.E engine starts  .  When it doesnt need to be charged the  engine stops and the car is in EV mode.
The engine driven generator  (or whatever regenerative braking generation is available )  does not charge the 12v battery directly.  This receives   its charge   from the HV battery   which gives it a charge of up to 14.4 volts or so, regardless of whether the engine is running or not.  Or in other words its charged by another battery, rather than an engine driven alternator as in a conventional car  (which also typically charge at 14.4 volts)

If the demand from 12v systems in the car is higher  the 12v battery needs to draw more power from the HV battery  , Its the need to keep the HV battery topped up that indirectly causes the engine to start  sooner and for longer ..  Its not to directly charge the 12v Battery.     

Sorry , I gave up long ago trying to predict when the engine will start and when it wont .  Its smart, and seems to defy logic.  it will often start when there are plenty of charge bars on the HV battery.
In warm weather  on first powering up you may be able to drive off without the engine starting at all   until a mile or so into your journey.    But if you have air con on it seems to predict power will be needed soon and the engine almost always starts up immediately, even if the HV battery is more or less fully charged.   

The HV battery charges up very quickly.  But the 12v battery is a conventional lead acid battery that takes longer.  Short and infrequent journeys dont give a long enough time for the HV battery to fully charge it.

Thanks, I was not clear what charges the 12V battery. The high voltage battery seems pretty small to be able to take care of the 12V battery charging without supplementary charge support via the engine/generator.
I continue to be surprised, unless it's just a cost saving, that most EV's and hybrids continue to use lead/acid batteries rather than lighter Lithium batteries. The reliability of the 12V battery is not just a Honda issue, there are many complaints of flat batteries on all makes of EV's

I have a charger on hand should I need it since my Jazz(when it arrives) will be used mainly for very short in and out of town trips.

[madasafish]

Prpblem with lithium  batteries is limitation on number of charge cycles  and deep discharges tend to lower capacity.

Lead Acid batteries ok for huge  current draw of starting a cold engine with a cold battery. Cold LI batteries not so good.(EVs have sometimes batter heating for winter use)

[Jocko]

The drain on the 12v battery and subsequent charging from the Traction battery is minuscule compared to the drain on the Traction battery by normal driving. The draw on the Traction battery is designed not to have deep discharge cycles. The ICE kicks in to prevent that.  Also unlike an EV, there is no requirement to reach such a high state of charge in the Traction battery. The traction battery should last the life of the car though its efficiency will drop a little with age.