Battery failure

[stani]

https://www.which.co.uk/news/article/revealed-the-surprising-fault-affecting-new-hybrids-and-evs-aWHWT7y2J77y

Honda not the worst but a problem we know

Yes, it's well written in that article. Now I know where the problem was with my Jazz - I drove very little in the winter (about once a week and a very short route) + then tried to update the system with the car not started.

[5thcivic]

Its obvious, manufacturers have over estimated the effectiveness of the main battery and have either just saved money on the 12V battery or under estimated the standby drain of all the electronic systems when switched off for circumstance at the end of the customer useage curve for low milage.

It would be a simple matter to monitor the 12V voltage when off and use the larger li-ion battery for a top up, but that would entail even more power useage when off, even if a intermittent timed measurement, say every hour. That power useage might affect the range figure, and that marketing number is now number one for advertising electric, and may just affect the mpg of hybrids too.

[stani]

5thcivic: A simple warning about the impending discharge of the 12V battery would be enough.
The system has a lot of warnings, but strangely not about the 12V battery.

[Jazzik]

https://www.which.co.uk/news/article/revealed-the-surprising-fault-affecting-new-hybrids-and-evs-aWHWT7y2J77y

Honda not the worst but a problem we know

Yes, it's well written in that article. Now I know where the problem was with my Jazz - I drove very little in the winter (about once a week and a very short route) + then tried to update the system with the car not started.

So, a clear example of point 2...

My two questions were:
1. Who among you has ever been unable to start the Jazz due to a dead 12-volt battery?
2. Was the battery perhaps discharged due to your own fault then? (Meaning: fumbling around with electricity consumers without having te car in "ready"?)

[jasonevans]

The problem with modern cars is there never really OFF as such.
Even when you lock the car the alarm , GPS etc are on draining voltage.
Hence why you need to go on a run every now and again to keep charge in the battery if you do very short journeys.

[coldstart]

...
It would be a simple matter to monitor the 12V voltage when off and use the larger li-ion battery for a top up
...

... and thereby risk a depleted HV-battery?
The 12V battery is quite easy to replace/recharge or jump start, whereas a completely drained HV-battery would be a catastrophic failure!

[5thcivic]

Well obviously there are already systems to prevent total discharge so that would not happen (even a zero mile left drain still leaves the HV battery in a state it will accept charge), besides the drain required would only be needed to boot the main micro systems, nothing like a starter motor, and such a system would need a warning through the app or otherwise that the owner needs to take urgent action. But that action would include the car starting and not requiring the AA or a charger that works from a flat 12V.

[coldstart]

Well obviously there are already systems to prevent total discharge so that would not happen (even a zero mile left drain still leaves the HV battery in a state it will accept charge)...

However, "accepting charge" doesn't necessarily mean "able to crank the ICE" - which is essential!
No AA will be able to help you, should the HV-battery fail!
(you do remember, that the Honda e:HEV drive train uses the HV-battery to crank the ICE?)

Addendum:
I still think that keeping the HV-system permanently active only to keep the 12V-battery charged would be a rather "marginal" idea - if it where a good one, I'm positive Honda's engineers would have considered/implemented it!
Let's face it: In the "olden days" you would have faced the very same problems if you where simply mistreating the car. So, just use the car as it was meant to be used, namely: driven!
Why on earth would you shell out 20 something K for a car only to be sitting in it listening to the radio?

[Fredbassett]

Going forward from my original post about total 12v battery failure my personal solution to battery drain will be to disconnect the negative terminal from the battery if I know that I won’t be using the car for two weeks or so (if I’m leaving it at an airport car park for example). It takes only a minute to do and is actually easier than putting a charger on. A disconnected battery will last for several weeks.

[RuthieB]

I’m using an ANCEL BM200 battery monitor on my battery which gives me voltage and state of charge……

See attached screenshot

and before any body makes an adverse comment the drain on the battery itself is minimal!

[Nicksey]

Going forward from my original post about total 12v battery failure my personal solution to battery drain will be to disconnect the negative terminal from the battery if I know that I won’t be using the car for two weeks or so (if I’m leaving it at an airport car park for example). It takes only a minute to do and is actually easier than putting a charger on. A disconnected battery will last for several weeks.

Have you done this with the new Jazz?

[ColinB]

Going forward from my original post about total 12v battery failure my personal solution to battery drain will be to disconnect the negative terminal from the battery if I know that I won’t be using the car for two weeks or so (if I’m leaving it at an airport car park for example). It takes only a minute to do and is actually easier than putting a charger on. A disconnected battery will last for several weeks.

Make sure you know how to lock & unlock a "dead" car without any electrics. Also be aware the alarm won't work, and you'll have to reset stuff like the radio and clock after an extended disconnection.

[5thcivic]

I still think that keeping the HV-system permanently active only to keep the 12V-battery charged would be a rather "marginal" idea - if it where a good one, I'm positive Honda's engineers would have

Well you're responding here to your idea, not mine. Monitoring the 12V battery does not need the HV on all the time and would be done on a scrolling basis, say every number of hours and would entail minimal current for the measurement since only a small part of the control systems would be necessary. A top could be done to prevent non starting but an alert sent to the app for owner engagement for low battery would be more useful.

The similar system is already in the E, where the app can monitor HV charging, pre program heating or climate control, tell you if locked, control the windows etc etc. And there are similar stories there of flat 12V if left for a time. But the engineers have decided it is not worth the effort to prevent presumably a small number of owners having the problem and it is just cheaper to install a small 12V battery.
 

[sebastiand]

Going forward from my original post about total 12v battery failure my personal solution to battery drain will be to disconnect the negative terminal from the battery if I know that I won’t be using the car for two weeks or so (if I’m leaving it at an airport car park for example). It takes only a minute to do and is actually easier than putting a charger on. A disconnected battery will last for several weeks.

Make sure you know how to lock & unlock a "dead" car without any electrics. Also be aware the alarm won't work, and you'll have to reset stuff like the radio and clock after an extended disconnection.

Is this complex in the Jazz? I'd totally do it if I need to leave home for like 2 months.

I mean if car settles it after 20-60 minutes driving after reconnecting the battery, i'd do it.

I have a neighbour with a LR Discovery 3 that leaves for 6-7 months every year and always asks a friend to drive the car once per month to keep the battery charged. Personally I'd just disconnect the battery if I was him (assuming it is possible).

[stani]

It would be enough if, after turning on the car, the system simply reported, for example, "your 12V battery has dropped in voltage, please recharge it"...