Battery Drain?

ewen1605

Active Member
Jan 17, 2016
253
1
Sheffield
Hi all,

I've got a two-year-old Leon FR having some battery troubles. Last week I encounted the problem for the first time - the electrics turned on fine, but the car was struggling to start. After a few tries it did start, and I managed to drive my journey of around 20 minutes. The car seemed to start alright for the return journey (just a minor hiccup).

This morning, the car wouldn't even unlock. When it finally did, only the rear doors unlocked. Then the front passenger door. Not the boot or the driver's door. The dials screen would barely turn on, and the car sounded like it was continuously attempting to lock and unlock the doors (except it wasn't working). No chance the engine was starting.

The car has been driven reasonably regularly even during lockdown - it's getting a few short trips every week, and at least one of about 20 minutes each way. I'm surprised really that the battery appears to have died as a result.

The only thing recently is that I had the car serviced on 28th April - I wonder whether something done at the garage could have caused an issue?

Can anyone advise? I've managed to get hold of a battery charger to use tomorrow.

 

mty12345

Active Member
Jun 17, 2011
3,728
451
bristol
Possibly something they did, although possibly just coincidence as well. This video may help you test how much current is being drawn.

 

SRGTD

Active Member
May 26, 2014
2,388
1,279
You might have a dodgy battery rather than the dealer having done something to cause this when your car was serviced.

There’ve been a few owners over on VWROC forum who’ve had their batteries prematurely ‘die’ , quite often when the car is between two and three years old. This wasn’t a consequence of lockdown, as this has been something that has happened to various Golf owners over recent years.

VW have replaced these defective batteries under warranty, and if yours is failing to hold its charge after two years, I’d hope that Seat would also replace yours.
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Maybe check and report back on which battery is fitted to your car, it will be an EFB type of battery - check to see if you can find the brand/manufacturer, it seems that the Moll branded batteries were the usual one to fail in early life.

To improve on things after getting that battery fully charged again, make sure that you switch off the auto stop/start as the car will always try to avoid charging the battery where possible and with a failing battery that will usually leave you stranded.

Make sure that you connect the -VE side of the charger to the car's body earth bonding point nearest to the battery, which will be very clos to the battery -VE post.

I think a lot of people will be misjudging just how long they need to drive before they have put back enough charge into a battery to cover what was used up to start it and then added some extra into it to cover parasitic losses between uses, and that is what every car needs right now with limited use.
 

Seastormer

Cupra Leon VZ2 300/CBF1000
Apr 25, 2014
5,007
693
68
Edinburgh (Scotland)
Maybe check and report back on which battery is fitted to your car, it will be an EFB type of battery - check to see if you can find the brand/manufacturer, it seems that the Moll branded batteries were the usual one to fail in early life.

To improve on things after getting that battery fully charged again, make sure that you switch off the auto stop/start as the car will always try to avoid charging the battery where possible and with a failing battery that will usually leave you stranded.

Make sure that you connect the -VE side of the charger to the car's body earth bonding point nearest to the battery, which will be very clos to the battery -VE post.

I think a lot of people will be misjudging just how long they need to drive before they have put back enough charge into a battery to cover what was used up to start it and then added some extra into it to cover parasitic losses between uses, and that is what every car needs right now with limited use.
You need to leave the car connected to an Optimate (or similar) that is designed for vehicles that don't get used much, and is safe to leave connected permanently. I have been using them for years on my bikes/cars and the battery gets tested, then charged and maintained by the unit so the car thinks it is getting used normally, and is always fully charged and ready to go. My Cupra 280 is currently connected to an Optimate 6 and the 6 year old battery is giving a full green light as it did when the car was brand new.
 
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Woody_72

Active Member
May 10, 2020
502
251
Northwest England
If you think you might have a parasitic draw issue and want to find out what's causing it, you can test with a multimeter. Set it to DC voltage and measure the voltage across the two exposed test points on the top of each fuse. If there is any draw on a particular circuit, you will see a potential difference of a few millivolts across the fuse. If you see no voltage drop at all, there is nothing drawing on the circuit.

Of course you could use an amp clamp on one of the main battery leads and pull each fuse in turn but most people don't have an amp clamp and the multimeter method is simpler.

And yes, I am a huge fan of South Main Auto and Pine Hollow Auto Diagnostics on YouTube :redface:.
 

ewen1605

Active Member
Jan 17, 2016
253
1
Sheffield
Thank you for all the replies. While I wish I was kitted out with a mulitmeter, I might have to rely on a local garage!

The battery is from the brand Banner.

I've managed to borrow a battery charger from a neighbour, so I'll give that a go. I've spoken to a local garage who are happy to run a diagnostic test on the battery.

I think I'm mostly surprised at how quickly the battery has died. In March, I spent two weeks in the States and the car was left for that whole time - not a problem when I returned. Throughout lockdown it has still been driven every couple of days for around 30 minutes. I know that's not a lot, but I wouldn't expect the battery to have completely given up. The car hasn't given any sort of indication or warning prior to this that the battery was (nearly) flat.

Also concerned that there didn't appear to be enough power to lock and unlock the doors - even with the key in the manual lock!
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Putting the key in the driver's side door does not rely on any power to unlock that door, but will rely on the same level of power to open all the others as when you use the remote. You will find that all the other doors are probably still deadlocked and so reaching the bonnet release and using it will be tricky, it seems like the breakdown services just get rough with the bonnet release and pull it out slightly to unblock it from the passenger side door pocket - and that does not normally snap it off.

That Banner brand battery, is it a genuine VW Group one or aftermarket? I know that Banner do make OEM batteries for car makers in USA but I did not think that they did for mainland Europe VW Group factories.
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
If you think you might have a parasitic draw issue and want to find out what's causing it, you can test with a multimeter. Set it to DC voltage and measure the voltage across the two exposed test points on the top of each fuse. If there is any draw on a particular circuit, you will see a potential difference of a few millivolts across the fuse. If you see no voltage drop at all, there is nothing drawing on the circuit.

Of course you could use an amp clamp on one of the main battery leads and pull each fuse in turn but most people don't have an amp clamp and the multimeter method is simpler.

And yes, I am a huge fan of South Main Auto and Pine Hollow Auto Diagnostics on YouTube :redface:.

There a lot more to using that method than you might understand, what you need to realise is, for parasitic drain checking on a car that seems to work okay but drains the battery when left for a few days is, most controllers get put to sleep a few minutes after a car is switch off, messing about with a door open on a car that had previously put its controllers to sleep will reawaken them and give you confusing answers as you will only ever carry out a valid test/check if you don't waken up controllers that have been sent to sleep.
 

Seriously?

Active Member
Apr 20, 2018
1,237
831
That Banner brand battery, is it a genuine VW Group one or aftermarket? I know that Banner do make OEM batteries for car makers in USA but I did not think that they did for mainland Europe VW Group factories

It seems like Banner is factory fit - we've got one in our 2018 ST and it's definitely the original
 
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RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
It seems like Banner is factory fit - we've got one in our 2018 ST and it's definitely the original

Fair enough, I always in the past thought that Banner was only a cheaper aftermarket brand that you typically only see being sold in small independent car spares shops, then I became aware that they are used as a supplier to Audi and maybe VW dealers as branded OEM replacement batteries!

VW Group used to seem to limit themselves to Moll, Exide and one other brand that Skoda normally used, but suppliers and supply chains do seem to have changed over the years which has lead to some maybe perceived as inferior brands being used at the factory in place of better thought of brands and that includes Mando for brake instead of ATE and TRW/Lucas and Champion's top level company who is now Federal Mogul being used for wiper blades instead of Bosch/Valeo.- you pay the same or more money and you get lesser/cheaper more Eastern manufactured parts fitted to your car, oh bother!
 

ewen1605

Active Member
Jan 17, 2016
253
1
Sheffield
I've had the car hooked up to a 12V charger for a few hours (I know realistically full charging would take longer than that) but doesn't seem to have changed anything.

After about 30 seconds it says "Power Supply - Workshop"
 

Seriously?

Active Member
Apr 20, 2018
1,237
831
Wow, just about every warning light and error message possible :(
Even though it's only 2 years old, I would guess that the battery is kaput. If you've got a dud cell (or 2), charging it probably isn't going to help.
 

Walone

Active Member
Feb 10, 2016
1,538
421
Near Heathrow
I've had the car hooked up to a 12V charger for a few hours (I know realistically full charging would take longer than that) but doesn't seem to have changed anything.

After about 30 seconds it says "Power Supply - Workshop"
What kind of charger are you using? The specification etc. Also might be an idea to disconnect the battery and charge it.
Needs to be charged overnight at least.
 
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RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Yep. And Microsuede instead of 'proper' Alcantara.

That and "almost the same as leather" that is plastic, that is shocking! I remember considering leather+Alcantara as an option for my wife's new Polo back in 2015, but initially the price put me off - the when I found out that it was just two different looking plastics - that was just deception and robbery by VW Group when selling that option on a 6C Polo!
 

Seriously?

Active Member
Apr 20, 2018
1,237
831
That and "almost the same as leather" that is plastic, that is shocking! I remember considering leather+Alcantara as an option for my wife's new Polo back in 2015, but initially the price put me off - the when I found out that it was just two different looking plastics - that was just deception and robbery by VW Group when selling that option on a 6C Polo!

Not just VW - most Mercedes described as having 'leather' have seats made out of a material called Artico - ARTIficial COw
 

cupra14

Active Member
Aug 31, 2017
332
63
England
Ideally, measure the battery voltage when not on charge and with headlights on for a minute or 5 first. If it's pretty flat it'll take 10-20 hours at a decent charge rate to have a hope of being charged - if it recovers at all.

The reason it takes so long is that the efficiency is low and the charger needs to shove lots in if the battery is quite flat.
 
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