Octavia iV Estate - flat 12v battery

[rmills]

Just now, varooom said:

Did you open your bonnet?

yes as the 12 volt battery needed to be charged

 

[varooom]

30 minutes ago, rmills said:

Despite having had the 27j6 update, my 12 volt battery is still discharging. The car has refused to start on two occasions. Can I ask if anyone has actually found a permanent solution to the problem? I don´t even get a warning any more that the 12 volt battery is low, the first indication that I have a problem is when the car fails to start.

 

I am hoping that a new 12 volt battery will solve the problem, but my dealer is refusing to change this under warranty. Has anyone had a battery replaced under warranty?

 

Such a shame as it is a great car.

I don't know if this is the cause, but exists TPI 2062011.4 Battery discharged - power steering control unit still active.pdf

 

In short, the error is caused by failing to finish the diagnostic session fully, and technician unplugs diagnostic tool too early.  The steering wheel control unit stays awake draining the battery.

 

They have updated software for this error if of course this is your trouble.

[rmills]

Just now, varooom said:

I don't know if this is the cause, but exists  

 

In short, the error is caused by failing to finish the diagnostic session fully, and technician unplugs diagnostic tool too early.  The steering wheel control unit stays awake draining the battery.

 

They have updated software for this error if of course this is your trouble.

That is interesting. Is there any way to find out if my car is affected? Do you have a copy of the TPI? Thank you

[varooom]

16 minutes ago, rmills said:

That is interesting. Is there any way to find out if my car is affected? Do you have a copy of the TPI? Thank you

Posted for all

Unless you know the SW version of your power steering, you won't know yourself.  Dealer will probably deny they ever did this to anyone's car.

[Sir_Ron_Norris]

1 hour ago, rmills said:

Has anyone had a battery replaced under warranty?

Yes, mine was replaced under Warranty in March 2022. Then I had the HV battery insulation mat fix in July 2022. I asked the dealer - "so does that mean the 12v is charged (as the manual states) at the same time the HV battery is charged?" They replied in the affirmative although, as with most answers from the dealers, I was left with the impression they weren't really sure. As to a permanent fix, I would draw your attention to the photos I posted here last July (further up this page) advocating the use of a CTEK unit. Of course this is only good if you have access to power in a garage. I am retired and my car can be left idle for several days, so I need the peace of mind this unit provides.

[Jim2015]

I've had two 12 volt battery overnight discharges. The first time, Skoda Assist came out and the second time I knew what to do. So now I plug the main charger in every night, which keeps the 12-volt battery resting voltage between 11.6 and 12v.

[rmills]

28 minutes ago, Jim2015 said:

I've had two 12 volt battery overnight discharges. The first time, Skoda Assist came out and the second time I knew what to do. So now I plug the main charger in every night, which keeps the 12-volt battery resting voltage between 11.6 and 12v.

So if I understand correctly the problem has never been solved as you have to constantly charge the battery?

[Warrior193]

2 hours ago, rmills said:

So if I understand correctly the problem has never been solved as you have to constantly charge the battery?

I assume that you are aware that at 11.6 volts your battery is more than 50% discharged - even with regular recharging, the life of that battery will be drastically shortened. 

[rmills]

Just now, Warrior193 said:

I assume that you are aware that at 11.6 volts your battery is more than 50% discharged - even with regular recharging, the life of that battery will be drastically shortened. 

Ok. So realistically how long should we expect a battery to last for? Mine started to fail after a year and a half

[varooom]

If the "starter" battery, or whatever they like to call it is EFB or AGM then 11.7V is 0% state of charge.

Usually they last for years, but they clearly don't like working in these models.

[Warrior193]

1 minute ago, rmills said:

Ok. So realistically how long should we expect a battery to last for? Mine started to fail after a year and a half

I would expect a reasonable life to be at least 4 to 5 years, I would not expect the hotel battery in a hybrid vehicle to have a shorter life than an ICE.  A lot depends of how the battery is treated - no lead-acid battery likes deep discharges or persistent undercharging.

Have you been told why your battery does not appear to be charging properly?  

[Warrior193]

@rmills has anyone actually checked the terminal voltage of the hotel (starter, etc battery) when the HV battery is charging?

[Warrior193]

6 hours ago, rmills said:

Despite having had the 27j6 update, my 12 volt battery is still discharging. The car has refused to start on two occasions. Can I ask if anyone has actually found a permanent solution to the problem? I don´t even get a warning any more that the 12 volt battery is low, the first indication that I have a problem is when the car fails to start.

 

I am hoping that a new 12 volt battery will solve the problem, but my dealer is refusing to change this under warranty. Has anyone had a battery replaced under warranty?

 

Such a shame as it is a great car.

 

video of the latest failure

Not the same as my Octavia is Mk3 - but I had both battery and alternator replaced in first year of warranty.

Replacement battery (Moll EFB) is still reasonable at 6 years, despite low annual miles.

[Warrior193]

21 minutes ago, varooom said:

If the "starter" battery, or whatever they like to call it is EFB or AGM then 11.7V is 0% state of charge.

Usually they last for years, but they clearly don't like working in these models.

Closer to 10%, but nowhere like enough to prevent drastic reduction of life.

Persistent undercharging, even at around 60%, (approx. 12.3 V) is not great for any lead-acid battery.   

[varooom]

8 minutes ago, Warrior193 said:

Closer to 10%, but nowhere like enough to prevent drastic reduction of life.

Persistent undercharging, even at around 60%, (approx. 12.3 V) is not great for any lead-acid battery.   

SSP504 shows as 0%

But as you say, too long spent at low Voltage is not good for any battery.

 

I am sure there are other charts, as said 11.6V or 11.7V is too damn low.

[rmills]

51 minutes ago, Warrior193 said:

@rmills has anyone actually checked the terminal voltage of the hotel (starter, etc battery) when the HV battery is charging?

I have just checked. Hybrid is charging and the voltage at the battery terminals is 13.1 volts. When charging stops the voltage is 12.6 volts. I think that the charging system is working correctly but the battery was already damaged from the 18 months prior to the recall (when it was not charging correctly).

[Warrior193]

10 hours ago, rmills said:

I have just checked. Hybrid is charging and the voltage at the battery terminals is 13.1 volts. When charging stops the voltage is 12.6 volts. I think that the charging system is working correctly but the battery was already damaged from the 18 months prior to the recall (when it was not charging correctly).

At 13 .1 volts, your hotel battery would barely be receiving a charge, correct charging voltage for AGM or EFB is around 14.7 V.

It is possible your existing battery has become badly sulphated, affecting the charge rate, but If that is the maximum charge rate available while the HV battery is being charged, I can see more problems in the future, even with a new battery. 

[Breezy_Pete]

13 minutes ago, Warrior193 said:

correct charging voltage for AGM or EFB is around 14.7 V

I think it would be more accurate to say 'maximum charging voltage for...'

Lower voltages will just be slower, lower current into the battery.

[rmills]

An update. Dealer has told me this morning that there is a new recall to deal with the problem of the 12 volt battery discharging under certain conditions. Apparently it is a software update. At least Skoda acknowledge that there is a problem. Once I have more info I will share it here

[Jim2015]

6 hours ago, rmills said:

An update. Dealer has told me this morning that there is a new recall to deal with the problem of the 12 volt battery discharging under certain conditions. Apparently it is a software update. At least Skoda acknowledge that there is a problem. Once I have more info I will share it here

Interesting. I contacted a nearby dealership to ask about the fitment of the battery insulating mat and was told that the nearest dealer who can do this is in Leeds, about 2 hours away. If they can do the work, I'll ask whether they can also fix the 12-volt battery discharge issue. I can anticipate a problem when I say that I don't want the car to be driven to and fro and will insist on it being transported by a trailer.

[Warrior193]

On 04/01/2023 at 10:18, Breezy_Pete said:

I think it would be more accurate to say 'maximum charging voltage for...'

Lower voltages will just be slower, lower current into the battery.

I suspect that if 13.1 volts is the maximum charge rate delivered, the hotel battery will not fully charge in the time it takes to recharge the HV battery. 

[rmills]

My car is going to the dealer next week to have the software update applied and probably a new 12 volt battery fitted 

[Jim2015]

20 hours ago, rmills said:

My car is going to the dealer next week to have the software update applied and probably a new 12 volt battery fitted 

Ours is going in for the software update on February 8th but no mention of a new battery.

[rmills]

26 minutes ago, Jim2015 said:

Ours is going in for the software update on February 8th but no mention of a new battery

If I do not charge my car for 2 days then my 12 volt battery is either flat, or it gives low battery warning messages. So not everyone will need a new battery, it is just that mine has suffered previously and is now dead

[rmills]

My car was updated last week. The garage confirmed that the software update to the gateway module was specifically to address the problem I had been having, where the 12 volt battery is completely discharged. The 12 volt batterywas checked and is apparently ok.

So i anyone is experiencing a total discharge of the 12 volt battery, there is a known issue and a software update available.