Battery

[Rall86]

Evening, 

I'm new. I have a skoda octavia 2018 1.6 tdi auto estate. 

The problem, my battery keeps going dead. Been to the mechanics and theres no problem with the alternator or battery. I have replaced the wire from the battery to the alternator but the issue is happening. Once i jump start the car i disconnect the wire from the battery to the alternator and reconnect it and the car is fine for the rest of the day. 

Thanks in advance for reading. 

 

[varaderoguy]

Yes....it's happening quite a lot. The AGM/EFM batteries are all dying due to age and lack of use because of COVID-19. The Skoda/VAG Batteries are also less than great too. You'll need to put in a new battery and update the serial number via VCDS or ODBELEVEN by one to allow the battery to start working again.

[bigjohn]

You may have a parasitic draw of some sort - any  thing like dash cams plugged in?

 

How do you know the battery is OK? Batteries on stop/start cars don't seem to last as long  especially because of lockdown's etc. My son's miKIII battery only lasted 3 years from new. Will be EFB or AGM and will need coding.

 

Edited 4 October, 2021 by bigjohn

[Rall86]

Thanks for the info. My mechanic thinks it could possibly be something to do with the ecu? Which is concerning. It's a taxi and i won't lie I've jad nothing but trouble with this model. £4000 spend in the last 4 months on repairs. 

[bigjohn]

3 minutes ago, Rall86 said:

 My mechanic thinks it could possibly be something to do with the ecu?

 

Seems to be a default money spinning answer these days - I'd start with a new battery and possibly a new mechanic.

 

Other than a new battery my son has had no trouble at all with his 2016 1.2tsi - owned since 2019.

Edited 4 October, 2021 by bigjohn

[Rall86]

To be honest the mechanic has a really good reputation. The car is 3 years old. Replaced the original battery at 2 years old. Now a year later the second battery is doing the same. And like i said earlier once I've jump started the car and disconnected the wire from the battery terminal and then connect it again it's fine. Starts everytime. Till the next day or 3 days later. Seems the alternator isn't being told to do it's job till I've done this. 

Thanks 

[Carlston]

What is the battery voltage when the engine is idling? Should be at least 13.8V

 

You can measure from the cigarette lighter socket with an "LED/LCD cigarette lighter voltmeter"

 

You can also disconnect the negative terminal and fully charge the battery. Leave it overnight with the negative terminal still disconnected, and then check the voltage. If you measure the battery directly (which you would have to do if the negative terminal is disconnected) the battery voltage should be at least 12.2V after being left overnight.

 

Make sure you use a good fully automatic battery charger such as this Bosch 12V C1 018999901M (as having a battery charger that keeps charging after the battery is full will ruin the battery):

https://www.amazon.de/Bosch-189-999-01M-Batterieladegerät/dp/B00RP3DEW6/ref=sr_1_16?__mk_de_DE=ÅMÅŽÕÑ&dchild=1&keywords=bosch+battery+charger+12v&qid=1633381897&sr=8-16

 

There are other good makes, but this Bosch is very simple to use.

 

This Bosch can charge any 12V car battery including AGM and other stop-start batteries.

 

Edited 4 October, 2021 by Carlston

[J.R.]

If it is s start/stop vehicle then disconnect the shut resistor wire from the battery negative lead (I think its the negative one) and leave it off, the alternator will then revert to the default normal charging regime and your battery will last a lot longer.

 

You will lose the stop/start facility by doing so.

[Rall86]

Thanks carlston. 

 

The battery voltage is around the 12 mark before i disconnect the wire from the battery terminal once reconnected it goes upto 14.odd. I have a buture booster which is very good. And fires my car up everytime. 

[Carlston]

13 minutes ago, Rall86 said:

Thanks carlston. 

 

The battery voltage is around the 12 mark before i disconnect the wire from the battery terminal once reconnected it goes upto 14.odd. I have a buture booster which is very good. And fires my car up everytime. 

 

12.0V is too low.

 

I never jump start or use a battery booster as these methods put too much current through the battery, which will reduce its life.

 

A gentle charge such as 4 Amps is much kinder to the battery.

 

Many new stop-start cars are being fitted with a cheaper EFB battery rather than the much better and longer lasting AGM battery.

 

If you still have the original EFB battery, simply replace with a new AGM battery from one of the best brands such as Varta.

 

Edited 4 October, 2021 by Carlston

[Rall86]

It's concerning the fact that it's my second battery in three years and this second one is only a year old. I also don't use the stop start i deactivate as soon as i start work in the morning. There has to be more of an issue that's causing this. Also i have had no warning lights. 🤔

[Carlston]

17 minutes ago, Rall86 said:

It's concerning the fact that it's my second battery in three years and this second one is only a year old. I also don't use the stop start i deactivate as soon as i start work in the morning. There has to be more of an issue that's causing this. Also i have had no warning lights. 🤔

 

It's easy enough to test the battery like I described above in my first post, then you will know if you need a new one.

 

What battery do you have? (Make, model)

 

This is one of the batteries that Varta recommends for the Octavia MK3 1.6TDI:

 

Silver Dynamic AGM 570 901 076

Model:

 

570 901 076

Capacity:

 

70 Ah

CCA:

 

760 A

Width:

 

175 mm

Length:

 

278 mm

Height:

 

190 mm

Short Code:

 

E39

UK Code:

 

096AGM

 

https://www.varta-automotive.com/en-gb/battery-finder?type=pc&year=2018&make=106&model=11196&engine=58766&etn=563+400+061|560+408+054|570+901+076|&rec_etn=560+408+054|570+901+076|&ss_etn=570+901+076|&literal_search={"type"%3A"Passenger+Car"%2C"year"%3A"2018"%2C"make"%3A"SKODA"%2C"model"%3A"OCTAVIA+III+Combi+(5E5%2C+5E6)"%2C"engine"%3A"1.6+TDI+(77+kW+%2F+105+PS)"}

 

Edited 4 October, 2021 by Carlston

[J.R.]

Your new battery may not be the corect type and/or the battery management controller has not been recoded for its parameters.

 

I think the battery management system, regenerative charging on over-run, only 75% charging etc remains active even if start:stop is switched off, it definitely reverts to a proper charging regime if the shunt resistor is disconnected.

 

I had guessed from what you said before that the battery had been changed and thats when your problems started.

[bigjohn]

What battery is currently fitted?

[ords]

If you can get the battery fully charged, disconnect one of the terminals and leave it for as long as possible & then try to start it. If it starts then you know the battery is ok & there is a current draw which needs investigating. Your battery will be covered by its warranty as it's only a year old. Get it checked out. Was the new battery coded when fitted?

 

I know it's the luck of the draw, but mine is on it's original battery, gets left for 6/8 weeks at a time and always has enough power to start up.

[Rall86]

Thanks for all the replies. 

I changed garages about 5 months ago. As i didn't feel confident eith my old one. When the old garage changed the battery the mechanic just took the old one out and put the new one in. No coding took place! 

The new battery make is banner. It's a stop start battery. Cost £170 from one of my local motor factors. I'm starting to It's a battery issue after all of these comments. Thanks again. 

[PetrolDave]

1 hour ago, Rall86 said:

the mechanic just took the old one out and put the new one in. No coding took place! 

So the battery management still thinks you have the old knackered battery...

[varaderoguy]

Its something that a lot of folk don't realise.  For all modern VAG vehicles, if you have a car later than 2014/5, you need to code in the batteries. 

[varaderoguy]

What you need to do is find somebody locally with either a VCDS or ODBEleven setup. 

 

You will find VCDS owners here

 

They can then code in the battery - we are also assuming that the battery is of the correct type (AFM/EGM) that can be coded in.

 

You can find the procedure here: http://wiki.ross-tech.com/wiki/index.php/Battery_Replacement

 

 

[cheezemonkhai]

I would put a new AGM battery in and correctly code the battery management system.

The problem could be as simple as the car thinking you have an old battery, but as you don't know the state of the replacement and it's your income, I'd just start with a known good battery and a known good coding.

 

It could be that the new battery sat for a year almost unused, which would kill it too.

The cars here have been on a smart charger once every 4-6 weeks during lockdown.

Others who didn't do that ended up with dead batteries that re-charged, worked for a bit and then didn't have enough grunt to start the car.
A jump start/charge would fix this and then the same would happen again a little later.

It could also be the charging system, but a coding will affect how that behaves, so I circle back to the new battery, correct coding and see how it behaves from there.

Edited 5 October, 2021 by cheezemonkhai
typo

[cheezemonkhai]

Worth adding your battery was a bit expensive, as even retail halfords is less:

 

https://www.halfords.com/motoring/batteries/car-batteries/halfords--096agm-start%2Fstop-agm-12v-car-battery-5-year-guarantee-548638.html

 

They're made by a reputable company and actually a very good battery. Trade get a discount on that too.

As such £179 for a battery, seems a lot since Halfords are not exactly known to be the cheapest.

The £25 fitting service even mentions registering the new battery with the car (not saying I'd use it, but if they know, you'd hope a specialist garage would have known).

 

Worth calling a couple of main dealers and getting a price for supply and fit (inc coding) of a new battery and see how it compares to other prices you get.

If it's about the same it's usually worth going to the dealer.

Edited 5 October, 2021 by cheezemonkhai

[nta16]

Rall86 - this battery coding was all new to me and I'd no idea how invasive the stop/start battery management computer programs are on the car but as I've been driving for over 40 years I've always known the great importance of having a good battery (and connections) in good condition and state of charge.

 

I've just exchanged posts on this subject - 

12 hours ago MozzyMarr said:

I know first hand about batteries and modern electronics, my previous car  (a 2010 Panda) developed a lot of strange ECU issues (and loss of power steering) and wasn't happy with the battery voltages before a cold start. I replaced the battery and the ECU issues never returned :).

nta16 said:

I bang on about this all the time but I think a lot of owners don't understand or too readily dismiss it.  With the first cold snap this year some will notice issues and the second cold snap could bring problems, and possibly breakdowns call-outs for some but it can be prevented.

 

Good advice has been given about not using a booster charger and that a long, low, slow recharge is best (especially if that's how the discharge was) but if you don't have the time for that then prevention is better than cure by using a battery maintainer if necessary but a good battery, coded in, kept in good condition and reasonable use shouldn't need too much attention.

 

[rum4mo]

I think that if it was a fault/failure with the BMS or its dongle, a scan using a VW Group compliant scan tool would confirm or rule that out, some people have had these dongles replaced under warranty it seems.

 

Needing recoding after a battery change even if the exact identical new battery is fitted, I agree in principle about doing that and would always recode any new battery I fitted to my cars, but has anyone bothered to check how much not doing that influences the usefulness or life of a new battery - I thought that the new battery would not be charged immediately as intended but over time the BMS would adapt to optimise that new battery or at least correctly charge it.  I'm just putting that out in a bid to stop the OP now "knowing" that as his car has not been recoded to this new battery, then that MUST be the only reason why he is having a problem.

[nta16]

Tayna - 096 AGM CAR BATTERIES - https://www.tayna.co.uk/car-batteries/types/096-agm/

 

ETA: I've just remembered, when I bought my battery in June there was apparently a shortage and the price was £9 higher than now (from Tayna).

 

What are the chances of a battery shortage at the second cold snap of this autumn/winter?

 

Edited 5 October, 2021 by nta16

[nta16]

6 minutes ago, rum4mo said:

I think that if it was a fault/failure with the BMS or its dongle, a scan using a VW Group compliant scan tool would confirm or rule that out, some people have had these dongles replaced under warranty it seems.

 

Needing recoding after a battery change even if the exact identical new battery is fitted, I agree in principle about doing that and would always recode any new battery I fitted to my cars, but has anyone bothered to check how much not doing that influences the usefulness or life of a new battery - I thought that the new battery would not be charged immediately as intended but over time the BMS would adapt to optimise that new battery or at least correctly charge it.  I'm just putting that out in a bid to stop the OP now "knowing" that as his car has not been recoded to this new battery, then that MUST be the only reason why he is having a problem.

A very good point - but with so much hassle already experienced a belt, braces, bit of string and chewing gum approach to the battery and the very invasive systems might not hurt.

 

The vehicle being used as a taxi, depending on the type of work journeys, could throw in the old "serve" use for the battery and the rest of the car, especially if there's a lot of idling, on the engine, dpf, etc., if it's long airport runs or such then it'd be different.

 

Perhaps that £170 Banner battery is too big to fully fill up.  🙂

 

As winter is approaching I've been thinking of doing a general warning thread about the battery but don't know where it'd go as it cover most models now.