Hi, I recently bought an approved used petrol Fabia III. It had been sitting on the forecourt for a while I think & the dash was warning of low battery voltage when I looked at it, but the dealer fully charged it before collection.

 

The car has been starting OK (though once it had the same battery low message, but the car is only used weekly), but I have noticed that the auto engine switch-off on idle doesn't happen much - usually the dash shows the crossed-out A. Today I was fitting a dashcam and noticed the battery voltage was 11.40V, and the cam wouldn't switch on until I started the engine, even though the car had been driven for an hour each of yesterday and today.

 

Could it be that the battery is degraded? The car was built Jan 16 but has <30k miles. Should I be concerned?

TIA! Simon

Quite a few posts knocking about on this, one just a few down. Probably best to have a read through some of it first. Have a check of previous MOT/services, mine has battery test results attached to each to show capacity and rated capacity.

 

 

Edited 8 March, 20206 yr by Confused_Cheese
typo

Thanks CC - sorry, was an impulsive q & I didn't put much effort into searching! So it seems there's much more complexity to batteries these days than whether it's just been left to go too flat... who knew?!

Edited 8 March, 20206 yr by Simon300

No problem. Yeah, tell me about it! Will get getting mine tested/sorted next time its with the dealer

I've been checking the "battery health" of a few VW Groups over the past few weeks, using a CTEK battery analyser to check overall health and the present CCA and VCDS to check for how the car's systems are evaluating the batteries. My Feb 2011 Audi S4 3.0TFSI 333PS  with an AGM battery, that car does not have Start/Stop is not used frequently but is always connected up to a CTEK battery maintenance charger when it sits in the garage, is still exhibiting really good CCA and capacity. My wife's August 2015 VW Polo 1.2TSI 110PS has an EFB battery, is used frequently and mostly for journeys over 6 miles each way, and especially  in winter I tend to switch off auto Stop/Start, is exhibiting quite good CCA and capacity. My mate's May 2018 VW T-Roc 1.5TSI 150PS with an EFB battery, is used a bit less than my wife's car and frequently for shorter journeys and always with auto Stop/Start left on, is exhibiting reasonably good CCA and quite low capacity.  My older daughter's May 2019 reg'd but not sold until August 2019 SEAT Leon Cupra 2.0TSI 290PS has an EFB battery and is frequently used for in town short journeys and always with auto Stop/Start left on, is exhibiting reasonable > poor CCA and quite low capacity.

 

So, it does seem to depend on how cars are being used when it comes to how well these EFB batteries survive, my daughter's Leon Cupra probably had a bad start to its life, ie delivered to dealer but then prepared for use but never taken to the sales area for a few months so suffered a flattened battery once of twice.

 

For what it is worth, all these 1.2TSI and 1.5TSI engined cars get a frame size 027 EFB battery, the Leon Cupra with its 2.0TSI engine gets a frame size 096 EFB battery - so next size up and the same as smaller TDI engined cars gets fitted with.

 

So, from what I've found so far, if and when the time comes to replace the 1.2TSI engined Polo battery, I'll either fit a AGM frame size 027, or more probably an AGM frame size 096 - I'll need to replace or modify the battery tray to fit the slightly bigger battery.  I'll be advising my daughter to replace her EFB battery with a same size AGM battery and I'll recode the car's battery management system, as I will need to do if/when the 1.2TSI Polo needs a new battery.

 

These EFB batteries are best suited to be fitted to new cars or cars being "moved on", if keeping a car for while, I'd always plan to fit an AGM battery - but that is only based on my experience of the 5 cars mentioned above.

 

Edit:- just one other car, a friend runs a December 2016 Audi A6 2.0TDI Exec and had to replace that car's EFB battery last month, his new battery is an AGM as it seems that car should have been fitted wth one of them at factory, he bought it slightly used so maybe a bad person swopped its original AGM battery for same size EFB battery! I never did get a chance to run any checks on the just removed EFB battery as his problem moved on quickly from "warnings" to failure to start.

Edited 8 March, 20206 yr by rum4mo

Thanks for your summary @rum4mo. For stop-start battery newbies like me I found this helpful https://www.yuasa.co.uk/info/technical/agm-efb-explained/ too.

It's all a bit beyond me - our car is not used regularly, but when it is it gets a reasonable run... can't help feeling it will fail to start one day though. It's covered Skoda's used car warranty so I can't tinker with it. I'll have to ask the dealer next time I'm in (perhaps they can test it on its annual service this summer).

Thanks again.

4 hours ago, rum4mo said:

I'll need to replace or modify the battery tray to fit the slightly bigger batter

 

I did find somewhere the part numbers for the battery trays. I put them on another post somewhere.

 

 

Edited 9 March, 20206 yr by FabiaGonzales

@FabiaGonzales, seeing as you have linked to that other thread and posting, that is the battery tray number that I had worked out should work with the slightly bigger battery, ie frame size 096, and to keep things in the same thread, the corresponding "battery case" which is the soft heat insulator for the slightly bigger battery is 5Q0 915 411E.

The tray is waiting until the weather gets warmer and the insulation is waiting until I feel the need to replace that EFB with a slightly bigger AGM as we will be keeping that car for quite a few more years, typically 10+ years unless it turns into a dog/money pit.