Clubjazz - Honda Jazz & HR-V Forums

Honda Jazz Forums => Honda Jazz Mk4 2020 - => Topic started by: PaulC on September 09, 2022, 09:43:07 PM

Title: HV Battery indicator occasionally showing 10
Post by: PaulC on September 09, 2022, 09:43:07 PM
Earlier this year our Jazz was involved in a minor rear end collision. The damage has been fixed by a collision repairer (=panel beater). Since then, occasionally when I start the car the High Voltage battery meter in the driver information panel shows the charge as 10 out of 10

The car will drive along in non-EV mode while the meter continues to show 10, then after about 3 to 5 minutes  of driving the car will switch to EV mode and the meter drops down into the normal range of 3 to 7.

My diagnosis is that the car's software control system needs a reboot (like Windows computers) to bring it back into normal behaviour.

Has anyone else experienced this?
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 10, 2022, 06:18:53 AM
Mine is the same. It will show 10 on powerup occasionally.

I can force it to show 10 if I give it a CTEK charge after a fortnights standing.

Other than that, my theory is that maybe you've powered down at a recharge high spot, 7 bars maybe, and the software needs a short while to recalibrate ?
Title: Re: HV Battery indicator occasionally showing 10
Post by: Neil Ives on September 10, 2022, 08:00:09 AM
I can force it to show 10 if I give it a CTEK charge after a fortnights standing.
Hold on a cotton pickin minute!
Your CTEK charge is for the small battery under the bonnet yeh? How can that affect the big boy under the back seat?
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 10, 2022, 08:05:02 AM
Exactly my point on a post I made ages ago, but, that's what happens.

CTEK the 12v battery till CTEK shows green, fully charged through all stages. Disconnect CTEK, powerup ....... 10 bars, every time, or every time I've remembered to look.

https://clubjazz.org/forum/index.php?topic=13973.msg110726#msg110726
Title: Re: HV Battery indicator occasionally showing 10
Post by: Jazzik on September 10, 2022, 09:42:51 AM
So you bought a Jazz plug-in!!!  8)
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 10, 2022, 11:43:33 AM
I just like to ensure the 12v battery is regularly checked and charged. It's not uncommon for mine to stand for 2 or 3 weeks and when I do charge it it does take quite some time so must need it.

A previous test I did was to connect the CTEK a day after a long run and it took about an hour to complete. After 2 weeks it can take over 5 hours.
Title: Re: HV Battery indicator occasionally showing 10
Post by: 5thcivic on September 10, 2022, 05:57:27 PM
I've just connected some flying leads to the 12V battery for trickle charging because I don't do many miles too, so will see if the 10 appears next time I charge up overnight.  ;)
Title: Re: HV Battery indicator occasionally showing 10
Post by: John Ratsey on September 10, 2022, 08:57:17 PM
CTEK the 12v battery till CTEK shows green, fully charged through all stages. Disconnect CTEK, powerup ....... 10 bars, every time, or every time I've remembered to look.
I'm impressed. :o :o The HV system is isolated when the vehicle is turned off some I'm wondering how the electrons not only jump across the gap in the isolator but also get boosted from 12V to 400V.

If the final part of a journey includes regeneration which leaves the battery at the top end of its normal operating range then the engine running at the start of the next trip to get itself and/or the vehicle interior warmed up will see the battery charge being increased. The cabin heating requirement in very cold weather means the engine keeps running to provide heat even when the battery is 7 bars or more. Turning off the cabin heating and using the heated seats enables the hybrid system to operate as designed.
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 11, 2022, 06:14:26 AM
I fully agree, the battery meter must be reading something else other than just the HV battery charge.

I'm just posting it as it occurs on mine.

Could the battery meter be reading both batteries ?
Title: Re: HV Battery indicator occasionally showing 10
Post by: Bristol_Crosstar on September 11, 2022, 09:26:20 AM
Normally the 12V battery is charged by the high voltage battery when the car is switched on. If the 12V battery is fully charged this won't happen, maybe it confuses the software somehow so it gives an incorrect reading?
Title: Re: HV Battery indicator occasionally showing 10
Post by: Lord Voltermore on September 11, 2022, 11:26:47 AM
My understanding  is that most Hybrids have a problem if left unused for too long because the 12v batteries are normally relatively small and modern cars have quite a lot of computer activity running constantly.   A few hybrids can utilise  a few battery cells in their large HV battery.

  It  doesnt need enough amps to actually start the car, and you might think that it wont need much to actually fire up the computer systems.  But I  read somewhere that part of the start up procedure  involves the computer  running checks  before  approving the start up  (not much power needed)  but then it needs to 'throw'   quite a hefty solenoid switch to  connect the HV battery.( Some cars have two such switches, I believe the Jazz only has one.)   IIRC this switching requires about 30 amps.   This is no where near as much as  conventional car starter motor,  but it does  preclude  just having a tiny 12volt battery for the computer systems alone.

I have gone  quite a bit longer than 2 weeks unused without topping up the 12 volt battery,  without problem  , but maybe I am pushing my luck.   I can probably manage at home, and can charge it, but what happens if its left for an extended period in an airport car park etc.   

I am debating whether to buy one of  these 'power bank' portable starters,  that are small enough to keep in the car  (only about the size of a paper back book).   They claim to be able to start a conventional car so should  easily manage the 12v hybrid start up procedure.        But they do seem more expensive than they were a year ago.- even allowing for recent inflation.   One of those things that I may never use and resent the cost, but invaluable should you need it.  It would be great being independent  of the need to call a breakdown service, , or trying to cadge a jump start from another car  -  or being able to offer help to others without endangering your own car. 
 
Title: Re: HV Battery indicator occasionally showing 10
Post by: Jazzik on September 11, 2022, 12:18:47 PM
Once, a long time ago, I bought an "intelligent" battery charger. It was a good offer, for the money you couldn't pass it up. That thing is sitting unused in the garage collecting dust. That while we have been driving a hybrid (with such a weak 12 volt battery...) for many years, which have also stood unused in the garage for several weeks. Never had any starting problems.
I don't think I'll put a power bank next to that battery charger, not even to help that nice neighbour. (https://www.cheesebuerger.de/images/midi/konfus/c086.gif)
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 12, 2022, 04:28:51 PM
Being as I haven't used mine since BH Monday 29th Aug I decided to photo the steps.

Power level was 3 bars, CTEK connected at 06:30. Still hadn't fully charged by 14:30 so give it a rest and turned CTEK off overnight. Reconnected this morning at 06:30 again and by 09:00 fully charged. Maybe sooner as I didn't check.

Powered up ....... cards on table, it only rose to 5 bars.

Oh well, failed this time.
Title: Re: HV Battery indicator occasionally showing 10
Post by: PaulC on September 13, 2022, 10:59:04 PM
We use our Jazz almost daily, for short trips of 8 to 25km.
I had the HV level meter show 10 yesterday.
Here's what happened. I backed out of the garage with the level meter showing around 7 and then the motor started to charge the HV battery.
I then drove off downhill and along a level road for about 3 minutes. During this time the motor charged the battery up to 10 but did not stop and continued running. The driver display showed "Ready" all this time.
I then came to drive up a long hill and as I started up the hill the motor stopped and the driver display showed "EV Ready" and the level meter dropped to 9 and continued down to the normal range of 7 to 3, at which point the motor started again to charge the HV battery.
After that the Jazz behaved normally as regards the HV level meter and the motor charging.
Very puzzling.
Title: Re: HV Battery indicator occasionally showing 10
Post by: John Ratsey on September 14, 2022, 08:12:50 AM
Did you have the cabin heating turned on? This will force the engine to keep running when the battery is well charged. Irrespective of the charge in the HV battery a cold engine will run on initial starting until it has reached operating temperature. Running the cabin heating adds to this run time while the car tries to get the cabin to operating temperature (enabling ECO mode reduces but does not eliminate this problem).
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 14, 2022, 09:46:32 AM
Yep, whenever I want a silent getaway in the wee small hours I powerup and instantly turn the heating off via the left hand button.

That almost always kills the engine.
Title: Re: HV Battery indicator occasionally showing 10
Post by: Jazzik on September 14, 2022, 10:19:07 AM
Did you have the cabin heating turned on? This will force the engine to keep running when the battery is well charged. Irrespective of the charge in the HV battery a cold engine will run on initial starting until it has reached operating temperature. Running the cabin heating adds to this run time while the car tries to get the cabin to operating temperature (enabling ECO mode reduces but does not eliminate this problem).

Bringing the engine up to operating temperature and bringing the cabin to the desired temperature by means of heating and/or air conditioning I do not see as a problem, but as something necessary. Even if as a result (also) the HV battery is fully charged (about 80%).
And yes... that might cost a few extra drops of liquid gold...
Title: Re: HV Battery indicator occasionally showing 10
Post by: Lord Voltermore on September 14, 2022, 11:28:00 AM

Powered up ....... cards on table, it only rose to 5 bars.

Oh well, failed this time.
Sorry, not sure what you mean.  The CTEK would indicate the state of charge with the 12V battery  but once its fully charged  can you expect  that further 12v  charging will now top up the HV battery?

Its possible the HV battery might show more bars during the procedure. I have found  it can sometimes temporarily show more bars when its only been sitting overnight.     I thought this  is just  superficial surface charging,  that might affect the bar  readings, but will disappear almost immediately in use. !2v lead acid batteries show a similar temporary false reading soon after charging so maybe HV batteries do too.
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 14, 2022, 11:36:10 AM
I fully realise that the CTEK only charges the 12v battery, but, on previous full CTEK charges I've noticed at the next powerup the display rising to 10 bars.

I know it's illogical, I'm just posting what has happened before.

Maybe the battery meter runs off a sensor that reads both batteries somehow ?
Title: Re: HV Battery indicator occasionally showing 10
Post by: Lord Voltermore on September 21, 2022, 02:40:18 PM
I've been and gone and done it.   Just received one of these   power pack car starters .

https://www.ebay.co.uk/itm/374248057779   It arrived next day.  But it  is bright yellow. I was expecting black.  No biggie, it will be easier to find  ;D

I haven't yet started a car using it, and hope I never  have to.  But I have checked that the  heavy duty 12 volt terminals give 12 volts.   It claims to be able to jump  start conventional  cars so I am confident it will cope easily  with just initiating the HV start up procedure  ???

I justified it to myself as it can  also charge  phones, camera batteries etc  when on  a long walk in the wilds.  And has a torch function    It weighs less than my phone, and about the same size,apart from being 20 mm (3/4 inch) thick.  Easily kept in the car or pocket etc.
Title: Re: HV Battery indicator occasionally showing 10
Post by: 5thcivic on September 21, 2022, 05:01:52 PM
I charged the 12V for the first time with an intelligent charger overnight, was on trickle next morning, HV battery on 5.

I haven't done any long journeys yet and have yet to see a 10, because of a lot of setting up the car on idle my displayed mpg is 56 so far from short journeys.
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 22, 2022, 05:02:17 AM
Mine only went to 5 on my last CTEK charge.

But, considering it started out on 3 before I connected the CTEK it does seem to interact with the sensor somehow. Or does it filter through and give the HV a tiny boost ?

Just guessing.
Title: Re: HV Battery indicator occasionally showing 10
Post by: Mark Dirac on September 22, 2022, 07:12:51 PM
Easily kept in the car or pocket etc.
You'll need to find a way to remind yourself to top it up every 6 months or so. If you allow it to discharge it will be ruined, and then when you need it to boost your car battery which is also discharged ...
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 23, 2022, 06:22:03 AM
On a recent Car SOS one mechanic said that a standing battery sulphates with non use and they showed a CTEK on the bench.

I'm considering using my CTEK weekly if the car is unused as it has a desulphation stage.

Update: After looking at the advice from CTEK's site once a month is sufficient.
Title: Re: HV Battery indicator occasionally showing 10
Post by: Neil Ives on September 23, 2022, 09:51:46 AM
A bit off topic:
The battery on my motorbike has completely discharged. My Smart charger will not charge it! I've just bought a second hand old style trickle charger that I believe will work.
Title: Re: HV Battery indicator occasionally showing 10
Post by: shufty on September 23, 2022, 10:16:07 AM
...I've noticed 10 bars a lot more frequently in the last couple of months.
Title: Re: HV Battery indicator occasionally showing 10
Post by: Lord Voltermore on September 23, 2022, 10:30:42 AM
...I've noticed 10 bars a lot more frequently in the last couple of months.
The ones with the cheapest beer ? ;D
Title: Re: HV Battery indicator occasionally showing 10
Post by: Jazzik on September 23, 2022, 11:41:43 AM
I'm considering using my CTEK weekly if the car is unused as it has a desulphation stage.

Update: After looking at the advice from CTEK's site once a month is sufficient.

With current energy prices? That will be an expensive battery... ;D
Title: Re: HV Battery indicator occasionally showing 10
Post by: Lord Voltermore on September 23, 2022, 12:38:37 PM
This was part of my reasoning for buying a power pack starter.   Normally I drive often enough to keep the 12v battery charged from the HV battery. But if by chance its unattended for long enough for the 12v battery to go flat  I have the powerpack as a back up for starting. It doesnt prevent any sulphating damage that might occur in the meantime   but at least I dont have to remember to get the CTEK out every month,which for me means faffing around with a long extension lead, and might not be possible if its in a  car park etc.

Thats assuming I remember to keep the power pack charged!   :-[ Its charged by usb, so I could top it up as and when I remember on a journey. And would check its charged  if  a downtime is  anticipated. It has a state of charge indicator and can last 6 months but they recommend charging every 3 months.. I can cope with that.

Just a thought . I sometimes have  a conventional powerpack on me for my camera equipment. It actually charges stuff quicker than a mains charger.  I could partially charge the starter pack with that  , and in the worst case scenario even partially charge either with my phone. (leaving enough power to phone for help when my cunning plan proves to be nonsense.)
 
Like the song  'Dem bones' . "The iphones connected  to the power pack, the power packs connected to starter  pack, the starter packs connected to the battery packs,the battery pack is connected to the HV battery pack..."   (Actually its an android phone but that doesnt rhyme . ;D)
Title: Re: HV Battery indicator occasionally showing 10
Post by: Kremmen on September 23, 2022, 01:04:04 PM
I'm fortunate to have my 12v sort of hardwired and when parked, in the garage, the CTEK is wall mounted and only inches from the battery.

Takes about a minute to connect as it's just a plug and no clips.
Title: Re: HV Battery indicator occasionally showing 10
Post by: guest11413 on September 24, 2022, 09:32:28 AM
Ford Escape  hybrid up to 2009 has emergency charge button to jump start HV battery from 12v system
https://electricvehicleforums.com/forums/ford-escape-hybrid-26/battery-push-button-25119/ (https://electricvehicleforums.com/forums/ford-escape-hybrid-26/battery-push-button-25119/)
If Honda uses jump start procedure like this and make it automatically triggered if 12v battery connected to charger when car powered off, this can explain why Kremmen see HV battery fully charged after using CTEK
But can we know if battery really charged or it’s bug ?
Yes actually, on full 10 bar charged HV battery we can drive around 2-4km in town in EV mode if no A/C or heater used, or sit in standstill car and use A/C for pretty long time before ICE will start  ( we can see 10 bars after true state of charge of HV battery reach 60%) but if we going downhill with 10 bars of HV battery in B mode some small amount of energy still going in to HV battery, if that downhill road long enough we can charge our battery up to 80%.
This also happens to drivers in winter when heater used, ICE working constantly to supply heat to cabin and when driver pressing braking pedal the regeneration stores some energy even after we se 10 bars of HV battery, but most of energy goes to motor generator that spins ICE for engine braking.
Title: Re: HV Battery indicator occasionally showing 10
Post by: Lord Voltermore on September 24, 2022, 10:33:01 AM
Easily kept in the car or pocket etc.
You'll need to find a way to remind yourself to top it up every 6 months or so. If you allow it to discharge it will be ruined, and then when you need it to boost your car battery which is also discharged ...

For me remembering to keep the power bank stasrter pack   topped up (as opposed to the cars 12 v and HV battery)  is simples .I'll do  it on Birthdays ,service date  and Christmas/new year .Works out about right for  a 3 month charge.    .More worrying was  Back in January the car was unattended for nearly 3 months  when I was off globetrotting. Any longer without being driven puts the HV battery at risk . I was able to keep the  12v battery charged by using a solar  panel battery maintenance charger permanently plugged in. .   Even in the short winter days it was enough that the car started  after 10 weeks.  It met the needs but a bit of a faff for  regular use. And although it claims it wont overcharge the battery if permanently attached, I'm a bit wary if its in summer sunshine.

But some owners may  need to be  wary about the 3 month rule for the HV battery  , if for instance they overwinter in the sun, or unwell and unable to drive for a while.  Its not enough just to start the car every now and then on the driveway.     The car needs to be driven for half an hour and pass through several charge and discharge cycles at least every 3 months  to keep the HV battery  healthy.  If you cant arrange this yourself I  am not sure what the alternative may  be . They say the  HV battery cannot be charged independently of the car, and thats probably true of home chargers.  But I'd be surprised if main dealers at least dont have an expensive HV charger and the knowledge of how to connect it up.   But having to rely on a dealership  is hardly convenient.