Battery drain when parked up

[xman]

What make of battery is fitted? Elsewhere its been reported that dealers are changing batteries made by Moll without question as a very large proportion of those fitted were faulty and VAG have recognised this and I think issued a TPI. They are being replaced by other makes such as Varta but apparently there is a severe shortage of batteries in their supply chain, presumably Moll have côcked up and no doubt there are arguments over who pays.

 

Also there is a software update that addresses problems with stop/start not working etc, afaik this is again a battery voltage issue, however no idea if the fix addresses the battery charge management or simply allows stop/start at a lower voltage/charge (which would be a poor solution as that would lead to even shorter battery life)

[D402]

It is a Moll battery. Stop/start keeps working even when the battery is struggling so I'd be glad to see that fixed. Due a service soon so I'll them to change the battery then.

[Gyp]

My stop start rarely works.

 

Using the CTek monitor, it's clear that even on a long run, the battery doesn't get as well charged as it does when connected to a charger

[IJWS15]

I have had a problem with a previous VAG car, battery was flat after a weekend, AA rollup and nothing wrong apart from discharge - asked me what I had left on (nothing).  We then worked our way round the car checking that everything was going off (yes it was)

 

He queried no load/everything off current with VW and the answer was an unbelievable 1.8A.

 

What amazes me is that the car only ran the battery down once, on one occasion it didn't move for 3 weeks and the battery was fine.  Had 4 VAG cars since and none of the others have done it at all but I am suspicious that if there is an M in the month, a T in the day you left it and a new moon it will run the battery down.

[xman]

56 minutes ago, IJWS15 said:

 

He queried no load/everything off current with VW and the answer was an unbelievable 1.8A.

 

 

Someone pulling your leg there..

 

My real, actually measured and monitored over many months, answer is ~15mA average (MY18 1.4tsi SEL). An old or aging battery may take more due to increased internal leakage. This is measued with a fully charged battery on float at 13.5 volts.

 

Don't know if a part discharged, at lower voltage battery would take more (due to internal leakage etc)

 

it can go briefly much higher, for instance, if you use Skoda Connect to query your car, but only for the period it's connected. It usually takes 2-3 minutes for all the electronic modules to go to sleep.

 

For the nerds among us, it appears to take ~1 to 2mA less if the car is left unlocked, presumably because alarm sensors are not active.

Edited 15 March, 2019 by xman

[StevePerks]

May be worth throwing in here:
A work colleague had a long running issue with flat batteries - booked in a few times to the local dealer and always no fault found.
Turned out to be a duff relay that was intermittently leaving the cooling fan on.

[D402]

Another month of bizarre battery behaviour. Drove Warwickshire to Glasgow, only just started the next time; left the car parked for a week, started fine despite it being a frosty morning. Seems it doesn't like heat but doesn't mind cold and a rest does it good!

Anyway, battery was confirmed as defective during service and replaced with a Varta one under warranty, seems fine now 

 to Trust Skoda, Redditch.

[Twinpack]

hi guys. i got some similar issues with battery drain over night. (superb mk3 l&k 2017) in one day i've noticed that the main engine fan start spinning at a high speed. and it didn't stop until the battery was completely flat. went to skoda garage , no answer. all good. I've spoke with my romanian mechanic and he told me that is a computer who's managing cooler system which is  broken. went back to skoda dealer i even give them the part number. theyve checked and admit that this computer is overheating on some cars , replaced under the warranty terms. hope will be useful for some of you.

[Anthonyh_b]

My battery went flat on a 2017 L&K. Took it to dealer who scanned the can and advised the torch in the boot could be faulty. The dealer put the battery on charge for a bit, run some tests and advised it should be fine. I took the torch out of its holder whilst a new one was being ordered. A week later the same thing happened. Pushed the service button. VW repair man came out and change the battery on the spot. First thing he looked at and advised the battery was one from a faulty batch.

[BriskodaJeff]

Pretty shocking that the mobile repair man knew more about the problem than the dealer. 

[Anthonyh_b]

It was the first thing he looked at. He still had to go through the mandatory stuff. Check it's being charged whilst the engine is running etc. Luckily both times the car was at home so had use of wife's car or motorcycle.