Can I ask for member's views on changing the car battery?  My handbook says that after the change, certain things may not work as expected or need resetting.  So I want to ask what you think of connecting some dry batteries to the 12 volt socket to keep the systems powered while the car battery is being changed.

I was thinking of 8 'D' cells in series.  I reckon that 8 new ones should give about 13.6 volts.  I assume the centre contact in the 12 volt socket is the positive, but I can check that with a meter.

Thanks for any comments

Stewart

 

Doing that sort of thing with batteries might keep the temporary driver and convenience info alive but you will still need the battery minder info resetting with VCDS for the change of primary battery.

I dont think its really necessary.

If you change "like-for-like" the battery monitoring module should be clever enough to recognise something has changed.

I would hope you only need to reprogram something, if you change for a different battery e.g. larger quantity.

 

All of the modules these days use flash or non-volotile memory to store information so you shouldnt lose any functionality when the battery is disconnected even for a long time.

51 minutes ago, Gabbo said:

All of the modules these days use flash or non-volotile memory to store information so you shouldnt lose any functionality when the battery is disconnected even for a long time.

... except that "low voltage" fault codes will be stored by several modules, and in some cases the presence of these fault codes disables some features/functions until the fault codes are cleared.

 

Changing a battery without access to a fault code clearing tool such as VCDS is a lottery in modern cars.

 

Had a new battery under warranty & its a PITA to reset everything personally, I'd get it done by the dealers

The car can self learn over a period of time if "like for like" swap is carried out....

 

HOWEVER it will throw up loads of fault codes (which will go away after a drive & off) & won't immediately properly charge the new battery as it will still think the old battery is fitted as it needs telling a new one is fitted  (by changing the serial number entry in VCDS by one digit).

 

If you are fitting a different type or bigger capacity then you need to alter various lines in VCDS...

Thanks to all for the info.  Sounds like a job for Halfords.

Stewart

I have just changed mine on an Octavia 3 and following the change there are no codes in the module and everything works fine. Just needed to drive 1000 metres to reset some datum 

5 minutes ago, Rogerboy said:

I have just changed mine on an Octavia 3 and following the change there are no codes in the module and everything works fine. Just needed to drive 1000 metres to reset some datum 

Your comment should read, everything apparently works fine.

Please post back shortly when you require another new battery, which you’ll hopefully have coded correctly.

Edited 7 December, 20196 yr by Kenny R

Cars with stop/start need their replacement battery coding...

 

 

15 hours ago, silver1011 said:

Cars with stop/start need their replacement battery coding...

 

 

 

  I didnt know this, how come?

I'm no expert by any means, so take this with a pinch of salt...

 

If you look at your battery, instead if just the usual positive and negative wires, there will be a third wire running parallel to the negative wire.

 

This additional wire allows the car to monitor the battery, and therefore supports the operation of the stop/start system.

 

When you replace the battery the car needs telling (i.e. coding) that it now has a new one fitted so that it knows that the battery it is constantly monitoring has changed.

Sorry to raise up an old thread.

Made the mistake of disconnecting the battery while mucking around with steering wheel (don't ask).

Long story short car is flashing up all the warnings like above and battery stopped charging. Car is at the autoelectrian now but it's now made me curious about vcds and OBD2 plug to sort out this sort of stuff myself.

 

Can anyone point me to the right sort of plug I need to get to connect my Octavia to my laptop?

Or can you use those cheap Bluetooth ones?

 

Appreciated

I purchased OBDeleven pro version from Amazon. You can use your phone to connect to your car and do all the coding. When I checked my battery it had been coded with lower amps than it actually had and also was coded as the wrong type of battery and not an AGM.

Thanks for that. 

So when I've got the vcds plugged into the car what do I have to change if keeping the existing battery? I read elsewhere that I just need to change battery serial number by 1 

I.e. serial number:xxxxx1 to xxxxx2?

Nothing.

Would it possible for disconnecting the battery to affect the alternator? Car is at the auto electricians and they said they have cleared the errors but the battery isn't charging.

 

Just a coincidence from disconnecting the battery and possible preexisting problem with the alternator??

Shouldn't do any harm to anything.

Really need to know voltage across battery posts without and with engine running; did you measure those before the car went to the autoelectrician?

How many km has the car done, and is it on the factory original battery?

Edited 28 August, 20205 yr by Wino

Unfortunately no. Only new to the whole OBD2 thing thanks to disconnecting the battery and subsequently having all the issues the last couple of days.

 

Guess I'm just gonna have to trust the electrician is doing right by me. Ain't cheap though!

You only need the cheapest of cheap voltmeters to read such voltages, nothing more technical.