I've had countless battery warnings in my 2016 Octavia SEL 1.4 TSI.  The battery is EFB.  The dealer has tested it three times and says it's fine, so won't replace it.

 

So, I'm considering buying a replacement, if only to avoid the constant hassle.  All the online vendors advise that this model should have an AGM, yet I've read these two types of battery should not be changed for the other (here).  Is this correct, or can I move seamlessly from EFB to AGM, assuming the car is re-programmed correctly?

Edited 27 April, 20188 yr by ms10
spelling mistake

Yes as long as it's the correct size so it fits then AGM or EFB is fine  - car should be coded with new serial number and battery type.

 

A 2016 should not need a new battery though, and is still under warranty. I'd push harder on your dealer or find another one to diagnose the issue. My 63 plate is still on its original EFB and no errors or warnings.

Edited 27 April, 20188 yr by ahenners

It also depends why you are getting warnings. If the battery charge is low, you get a warning. It’s not necessarily a battery fault but an indication that its not fully charged. Could be because of too many recent short journeys, not enough engine run time, an accessory left connected, and so requires more charging or it’s been discharge damaged previously reducing capacity making it more prone to flagging warnings. 

 

It won’t do any harm to up spec the battery to AGM or keep EFB if it’s programed in properly. Just don’t fit a standard battery as stop start tech will wear it out very quickly or use one with less capacity (lower ratings on the label). 

 

For peace of mind, a change of battery won’t hurt. 

Edited 27 April, 20188 yr by BigEjit

27 minutes ago, ahenners said:

A 2016 should not need a new battery though, and is still under warranty. I'd push harder on your dealer or find another one to diagnose the issue. My 63 plate is still on its original EFB and no errors or warnings.

 

Are batteries covered under warranty though? Thought they were classed as consumables.

Depends on the issue. Weakening from discharge damage is not a manufacturing fault, it’s caused by ‘neglect’ or insufficient charging. Long term stored cars and low mileage runabouts are prone to this. Batteries are changed out under warranty with this condition but it’s down to the dealer discretion. If you recently bought the car, you could argue it was compromised at point of sale and get it done on ‘sale of goods’. Had the car a while, it’s more difficult to argue unless in the vehicle history it was laid up for a 6 weeks or more without any battery care. 

 

An internal failure like a short circuit where an OK battery suddenly drops to 10.5 (+/- 0.5) volts, won’t recover under charging and will never be able to get a car started is a warranty issue. 

Edited 28 April, 20188 yr by BigEjit

13 hours ago, tunedude said:

 

Are batteries covered under warranty though? Thought they were classed as consumables.

 

As @BigEjit posted above, certain issues are clearly not wear and tear but a fault which should be covered. Especially under the Manufacturer warranty.

 

Clutches are also generally wear and tear items but I had one replaced at 55k on my MK2 Octavia VRS under warranty due to a fault.

Well I've just changed the battery on my car as it's been laid up now for nearly 8 months. Despite having a battery conditioner on it, the battery still managed to die.

 

I changed mine yesterday and when checking the vcds info, I discovered the car had been told it had a 68ah battery in it, but it was actually 70ah. The battery type was also set to fleece, which I know is an agm type, but is would have assumed they'd have set it to agm.

 

I think 8 months inactivity has broken mine, but I can't see the vcds options doing it any favours.

Going from EFB to AGM shouldn’t be a problem. EFB is basically an entry level AGM battery. Assuming you have stop start and battery management system the battery needs to be coded to the vehicle. AGM is used for higher spec cars, so for instance if you were going from AGM to EFB it would be pointless. However there could be an underlying issue that you are having 

Hi Everybody!

Can anyone have proper tech input on below?

I have my octy 3 MY2013 w 1.6 CRTDI and start-stop and it has an AGM battery. Since I bought it 2nd hand from a VAG dealer, I don't know if the OEM spec is AGM or EFB.

Everywhere I read that AGM would connect to higher spec cars (start-stop + brake recuperation and/or high consuming convienence stuffs), so I doubt my octy would really need AGM battery.

I can imagine, that in 2013 EFB was still not available, so that is the reason for the AGM battery   OR 

I can also imagine that the battery was already replaced and they put AGM.

 

Does anyone know if I can "go back" with my octy 3 to EFB? Will it simply accept or some special hackaround would be also needed?

(BTW: I don't use the start-stop system, so I don't worry about the "performance" point of AGM vs EFB, just worry about the factory (VAG) tweaks to sell more expensive parts...)

 

thanks for any support! cheers! G.

If you change the type or capacity of the battery then you must change the data held by the battery management system, if you don't then there is a very real chance that it will think it needs to protect the battery from being discharged too deeply by turning off power consumers.

 

Even if you replace with the same type and capacity battery you need to change at least the battery serial number held by the BMS otherwise the same kind of power management can happen.

Edited 4 November, 20196 yr by PetrolDave

THANKS A LOT @PetrolDave

And do You possibly know if EFB would work or only AGM?

1 hour ago, Greg_B said:

And do You possibly know if EFB would work or only AGM?

My 2015 1.4TSI has been fitted at the factory with an EFB battery, several members here have fitted an AGM battery when their original EFB battery failed.

 

I plan to fit a larger AGM battery when my EFB battery fails - and recode the BMS as necessary using VCDS.

I had a replacement EFB battery fitted , eventually, under warranty.  Moll brand, with known failures.