Hi, I'm a new member having just bought my 2015 Fabia on Monday.

 

It's a 1.2 TSI (110) with a manual gearbox, one owner from new and just 12,700 miles.

 

There is however a battery problem. Whilst setting up the Bluetooth, stereo and other car settings the display came up with a warning that the battery was low and that the display would shut down if the car wasn't started. Due to the Coronavirus lockdown the car hadn't been driven or started for two days. 

 

I have charged the battery (the original) using my CTEK charger (suitable for stop/start batteries) and it went through the full charging cycle correctly. Using a multimeter the battery was showing 12.87v immediately after being chatged. The battery SOC display read 80%. After locking the car and leaving it overnight the SOC display read 60% and the multimeter showed 11.42v the following morning. 

 

The radio was off when the ignition was turned off, all interior lights turn off when the doors are shut, as does the glovebox light and the boot light. There is nothing plugged into the 12v socket or the USB socket, therefore I can't see any obvious cause for power draw whilst the car is locked.

 

I've explained the issue to the dealer (who is shut due to the lockdown) and he is arranging for a new battery to be delivered to me next week.

 

The manual seems to imply that swapping the battery is a simple job, but the radio (Bolero) may need recoding. Looking on this forum I've seen replies to similar topics for other Skodas varying from "it's a simple job, just swap them over - the radio code is stored in the car and it will recode automatically" to the radio code needing to be re-entered and the battery needing to be matched to the CPU, through to the world as we know it ending if anybody other than a Skoda dealer attempts the job!

 

I have jump leads and a slave battery to allow a continuous 12v supply to be maintained during the swap if required.

 

Has anybody on here swapped a battery on a Mk3 Fabia that could advise please? 

There's a recent long trail of woes about Fabia batteries. I have a 2016 model (but with DSG) and I had the same problem. I am absolutely certain that it is due to the BCM (battery control module, part of the electronics software) that is totally rubbish.

To overcome the problem, I just disconnected the sensor from the negative terminal of the batter. It is a little plug that you need to push back the locking tab and then pull the plug off and tuck it out of the way. You'll then find that you have overridden the stupid system that keeps the battery at 75% charge when just driving short journeys and defeats the start/stop permanently. After removing the sensor connection, either go for a longish run or charge the battery from a charger. You'll no longer get the annoying, stupid message until the battery genuinely fails.

Here is that post https://www.briskoda.net/forums/topic/477138-battery-low-warning/

 

 

Thank you, most interesting. I'll see how it goes when the car is in daily use once the world gets back to normal, but can see myself unplugging the sensor! 

 

I'm still surprised at the amount of power lost overnight with the car locked and stationary, so am assuming that the battery is on the way out as well.

You know, I'd never read the manual on replacing the battery 🤔 From reading around it a lot, I was under the impression that when installing a new battery on a vag vehicle with start/stop then you must change the serial number of the battery via vcds so it knows it a new battery so its management control charged it full(er). No mention of that in the manual though, interesting.

4 hours ago, Confused_Cheese said:

You know, I'd never read the manual on replacing the battery 🤔 From reading around it a lot, I was under the impression that when installing a new battery on a vag vehicle with start/stop then you must change the serial number of the battery via vcds so it knows it a new battery so its management control charged it full(er). No mention of that in the manual though, interesting.

 

From what I can make out that is true if you are swapping to a different capacity, size or battery type, such as an AGM. If it is a like for like swap then I don't think that there is any need to change serial number. The only grey area for me is battery manufacturer - would an identical spec battery from a different manufacturer require recoding?

 

Inputting the serial number sounds like a dealer job to me, or would Halfords do it if I bought a battery and fitting service from them? This is my first car with such technology and whilst I am practical, my knowledge lies mostly with classic cars without any computing tech!

 

It would also seem that unplugging the sensor on the negative terminal bypasses the whole issue and allows any battery to be fitted, albeit losing the stop start function.

My understanding of the reasoning behind changing the battery serial number is so the BCM then 'knows' that the battery has in fact been replaced - any fault in the previous battery that MAY have been limiting the charge/discharge rate will now be ignored and the BCM should adopt the default settings for a new battery of the stated type and capacity. If, at a minimum, the battery serial number is NOT changed when replacing a faulty battery, the BCM will almost certainly continue to charge the replacement at the previous (probably incorrect) rate.

 

In my opinion the BCM really should be configured to recognise when the vehicle is being frequently driven short distances only - and increase the allowable charge-rate closer to 100% (say 90-95%) to compensate. I believe the present rate is kept at approx. 75-80% to allow sufficient spare capacity for energy recuperation, avoiding possible overcharging - which does not occur to any significant degree on short trips. 

Edited 29 March, 20206 yr by Warrior193
Typo

As above.

 

Edit:- there is also a school of though/guess, that the battery charging will adapt itself over time so might even eventually sort itself out without you needing to do anything.

 

Put it this way, in the current situation, if your garage delivers a new battery to you, you would be no worse off and probably a lot better off fitting it and doing what you can until the situation eases enough for you to get someone to change that battery's serial number by one digit.

 

Just make sure that it is an EFB or if you are lucky an AGM battery that gets supplied - they always have that info printed onto them, and the same capacity - ie no less than the original battery if it is the factory fitted one still in that car.

Edited 29 March, 20206 yr by rum4mo

I'm getting this low battery warning thing on my 2016 mk3 and have had it for about 6 months now. I only do short journeys 2 or 3 times a week.  The always starts though. I have been attaching an Optimate 5 charger and checking the battery voltages. I'm getting 12.27V after a charge dropping to 12.15V 24 hours later. Compare this to my Berlingo van that has sat there for a couple of weeks and it's holding a healthy 12.6V (with alarm and tracking device). I notice I have the red ring on the built in battery indicator so it must be on it's way out (or just hanging on). So....not hijacking the post my interest is as also in whether I can just swap a battery over without specialist equipment and knowledge......and it used to be so easy!

 

As things are currently I would only want to  order a home delivery battery and fit it myself but I will hang on as I have 2 other functioning vehicles (oh yes and the motorbike).

 

I'm also wondering what unforseen consequences disconnecting the auto stop/start lead could have?  Mmmm?

I've had the sensor disconnected for 9+ months and the only affects are the battery charges properly and start/stop is disabled. 

My only concern is if you have a DSG box. If you do have one, then when you stop, the engine doesn't, so the clutch is wearing continuously (a problem with all the VAG DSGs fitted in the small engined cars) . Being aware of that, I always slip the selector into Neutral. As long as you foot remans on the brake, you can instantly flick the selector back into drive for a fast take off. It doesn't take long for it to be a habit. 

Mine's not a Dual as far as I know. So is there an overcharge issue? Are there not other systems that monitor the charge, do alternators have the ability to shut off recharge?

DSG = (semi) auto gearbox.

There's no over charge issues. Basically, the software stops the alternator charging more than 75% and only allowing more charge in engine overrun conditions. Overrun charging occurs mostly on long, fast runs, so if you use the car for mostly local use, the battery never fully charges. It also tells the start/stop system that the battery is sufficiently charged to operate. There's no downside other than losing start/stop and for me that's a positive benefit. 

Thank you for your replies, all very interesting reading.  Oh, the complexity for something that used to be so simple!  

 

As my CTEK charger believes that the battery is in good condition and the issue appears almost usual, I think that I shall leave everything well alone unless I experience any starting problems once I get to actually use the car on a daily basis.  Until then I shall bear in mind all of the advice kindly given, keep the new battery in stock and go back to fettling my Austin Mini with its simple electrics!

Agreed. Grossly over complicated for such minuscule gains. Only the garages win. 

1 hour ago, TerFar said:

DSG = (semi) auto gearbox.

There's no over charge issues. Basically, the software stops the alternator charging more than 75% and only allowing more charge in engine overrun conditions. Overrun charging occurs mostly on long, fast runs, so if you use the car for mostly local use, the battery never fully charges. It also tells the start/stop system that the battery is sufficiently charged to operate. There's no downside other than losing start/stop and for me that's a positive benefit. 

Does DSG have the paddles to change gear?

29 minutes ago, Fabia3iow said:

Does DSG have the paddles to change gear?

 

Usually an option or specification / model depending.

Cheers. Mine is manual, just needed reassurance lol!

They can if the upgraded steering wheel option is chosen. But it's not available across all ranges. I believe the older Fabia Vrs models had paddles, but the majority of Fabias with DSG don't. 

Thanks. So it's a dilemna isn't it? I'm looking at batteries online and EGM one's are expensive but I guess I need to fit a like for like one in case I need to re-attach the low voltage warning lead (haven't taken it off yet btw). Presumably Skoda dealerships are pretty pricey? I have a Euro Car Parts nearby but they only seem to sell standard wet flooded type no sign of EGM. 

Where do you guys go to purchase a new battery?

32 minutes ago, Fabia3iow said:

Thanks. So it's a dilemna isn't it? I'm looking at batteries online and EGM one's are expensive but I guess I need to fit a like for like one in case I need to re-attach the low voltage warning lead (haven't taken it off yet btw). Presumably Skoda dealerships are pretty pricey? I have a Euro Car Parts nearby but they only seem to sell standard wet flooded type no sign of EGM. 

Where do you guys go to purchase a new battery?

When I looked Halfords were about the cheapest for an AGM battery, £146 fitted and coded.

2 minutes ago, lordcroker said:

When I looked Halfords were about the cheapest for an AGM battery, £146 fitted and coded.

Thanks lordcroker, that pretty good for an AGM battery compared to some prices I've just looked up 👍

FYI.

 

The Fabia III has an 027 EFB battery . 

The 027 AGM Battery has a higher rating.

 

If you change from an EFB to an AGM battery then coding is required. See here:-

https://www.golfmk7.com/forums/index.php?threads/how-to-retro-fit-a-bigger-capacity-battery-to-a-mk7-golf.320084/

 

EFB = Enhanced Flooded Battery. If you pick it up and shake it you here the liquid sloshing around.

AGM = Absorbent Glass Mat. If you pick it up and shake it you DON'T hear anything sloshing around.

 

Thanks AG Falco

I think that the other difference between EFB and AGM is, the AGM battery will last a lot longer than the EFB so £/year the AGM battery should work out cheaper - as said best to get the CAN-Gateway battery technology changed from EFB to Fleece if you do change to AGM.

 

Don't ever consider buying a normal lead acid battery as they don't like Stop/Start and probably Smart/Rough charging.

As far as coding goes I will leave that to the installers. Presumably Halfords will be able to sort that?

13 hours ago, rum4mo said:

I think that the other difference between EFB and AGM is, the AGM battery will last a lot longer than the EFB so £/year the AGM battery should work out cheaper - as said best to get the CAN-Gateway battery technology changed from EFB to Fleece if you do change to AGM.

 

Don't ever consider buying a normal lead acid battery as they don't like Stop/Start and probably Smart/Rough charging.

Unless you disconnect the battery monitoring connector. In which case the charging system reverts to a standard charging mode which works fine with standard lead acid batteries.

 

Connecting it when you get to the dealer for servicing or MOT and disconnecting it afterwards will keep them quiet, and the battery won't really take any harm from anything they can do to it in the couple hours they'll have the car.