Hello

 

I'm after some help as I have recently bought the car and stop start isn't working, so from my previous car was a vauxhall astra and had the same fault and it turned out the battery wasn't holding enough charge.

 

I have checked the voltage at the battery on the Octavia and its really high at a standing of 22 volts and when the engine is idling its even higher at 26 volts surely this cant be right?

 

The battery is a Varta AGM 68ah which I have checked is a stop start battery so the correct one is fitted.

 

The main display also shows that there is the a high power consumption so the stop start wont engage.

 

I'm not too worried about the stop start not working but the high battery voltages at idle and running is very concerning but this is my first Skoda so I'm not sure on how they run voltage wise but my previous Astra the battery was around 12 to 13 volts at rest and about 14 to 15 volts when running.

 

Any help would be greatly appreciate as I dont wont to ruin the battery or alternator or this could be how they run but it doesn't seem right to me.

 

Thanks in advance to anyone that can help put my mind at rest or can advise if it is a fault on how to retifify it.

 

 

1 hour ago, Bigbelly said:

I have checked the voltage at the battery on the Octavia and its really high at a standing of 22 volts and when the engine is idling its even higher at 26 volts surely this cant be right?

If the voltage is really that high then somerhing is SERIOUSLY wrong, the voltage should never be above about 15V!!!

 

Sounds like your alternator regulator is not regulating, get it looked at and fixed ASAP before some serious damage is caused - and be prepared to need a new battery if this one has "boiled".

Edited 20 February, 20251 yr by PetrolDave

The voltages are absurd. Are you confident the used meter is working OK? It sounds like the voltages are approximately double of what they should be. And that sounds dangerous, like having a hydrogen electrolyser under the hood lol.

 

Octavias should have common ~12 V rest voltage and 14-15 V charging voltages.

 

I wud expect the battery to be dead already if the readings are correct.

1 hour ago, Bigbelly said:

I have checked the voltage at the battery on the Octavia and its really high at a standing of 22 volts and when the engine is idling its even higher at 26 volts surely this cant be right?

Those voltages should have fried most of the electrics if accurate.

When the battery is disconnected, what's the voltage then?

Thanks for all the replys.

 

I have checked again with a friends multimeter and the readings were 12.69 volts with the engine turned off and at idle with nothing inside the car turned on and it was showing 14.85 volts.

 

I feel a bit stupid now as I didn't think that my multimeter could be faulty and to try another one, but it is only a cheap screwfix lap multimeter that I have had for a fair while and I only use it for diy testings occasionally.

 

Has anyone any ideas to why the stop start doesn't work still as the battery has a good charge and the main display always states says there is high power consumption?

This is without any air con, heater or demistors on everything high drawing is turned off, it occasionaly says that the engine needs to be running which at the time it was but that is intermittenly displaying on the main display.

 

Thanks in advance

Check the voltage when cranking the engine on the key. Anything below 10 - 10.5v indicates a likely failing battery.

Had you unwittingly set the meter to read AC volts and not DC volts?

1 hour ago, Bigbelly said:

Has anyone any ideas to why the stop start doesn't work still as the battery has a good charge and the main display always states says there is high power consumption?

Ask a reputable indy or fast fit place to do a deep load test on the battery. This should be free on the understanding that if the battery fails you buy the new one from them.

Your (second) set of voltage readings seem fine. Bear in mind that the static volt reading just after the engine has been running will display a (slightly) higher value than it truly is. Measuring the voltage from the positive pole to the earth point may identify a different voltage, meaning your earth strap or contact has become suboptimal.

 

Your ECU is reporting a high drain, which in turn will not allow stopstart to operate. The tedious part of the analysis is now identifying which part of the car is responsible - is the heated windscreen really off when you switch it off, for example? A scan may or may not help here. Good luck

Varta is not an OE supplier so the battery has been changed, when it was changed was the car's battery management system recoded?

 

Do you have any obvious extra electrical devices such as a dash cam, cool box, etc.?

 

Failing that something is not turning off when it should, and the best way to get more clues is a fault code scan with e.g. VCDS or OBDeleven.

Edited 20 February, 20251 yr by PetrolDave

1 hour ago, Paws4Thot said:

Ask a reputable indy or fast fit place to do a deep load test on the battery. This should be free on the understanding that if the battery fails you buy the new one from them.

 

I think I'm one of the few people that still use a proper load tester, most garages use the electronic ones so they can repeat the pessimistic and aléatoire readings of X% life remaining to the punter, even I use the electronic one first for convenience.

 

When I was travelling I converted a Nissan Prairie to a campervan in New Zealand, I went to buy a second hand battery and the guy put the exact same old school load tester on it trying to pull the wool over my eyes by reading off the voltmeter scale showing green for good without pressing and holding the shunt switch, he was not happy that I knew how to use it properly and made him engage the load for  seconds, the battery was good enough for my needs and I paid a lot less than he was trying to rush me for.

There’s always the possibility that stop/start has been disabled, using OBDeleven or similar, although that wouldn’t give you the ‘high consumption’ message AFAIK. 

It. Could be worthwhile going for a longer drive to see whether the stop/start kicks in when the battery gets to a decent level. If it does kick in, then the battery is falling. 

Good luck. 

New battery needed typically. How old is it?

6 hours ago, daveo138 said:

There’s always the possibility that stop/start has been disabled, using OBDeleven or similar, although that wouldn’t give you the ‘high consumption’ message AFAIK. 

Has s/s ever worked since you bought the car?

14 hours ago, PetrolDave said:

Varta is not an OE supplier so the battery has been changed, when it was changed was the car's battery management system recoded?

 

Do you have any obvious extra electrical devices such as a dash cam, cool box, etc.?

 

Failing that something is not turning off when it should, and the best way to get more clues is a fault code scan with e.g. VCDS or OBDeleven.

That's interesting to know. Mine was bought as an ex demo at 6 months old from a Skoda dealer and came with a Varta battery which is still fitted. Would it have been changed within the 1st 6 months?

23 hours ago, Bigbelly said:

have checked the voltage at the battery on the Octavia and its really high at a standing of 22 volts and when the engine is idling its even higher at 26 volts surely this cant be right?

You are absolutely right.

Some expert intervention is required immediately or you could/WILL damage your battery and possibly some other electrical components that were not expecting to find themselves handling over 20v.

Most Octavia's will be getting to the stage where they need a new battery.  This is because most modern batteries have a life span of about 5 years before they need replacing.

My usual rule of thumb: if the CCA test is 20% below the battery capacity, its on its way out.  e.g. if you have a battery of 680CCA it shows below 544CCA, then it is probably time to start looking at replacements.

 

I got a cracking deal on a new Varta battery (ironically made in the Czechia), its a 70Ah capacity.  Just a case of coding in the new battery.

I used to get some weird messages about why S/S wasn't working on a Superb 3 that I used to have.

 

Not much help, more for entertainment. 😀

 

 

11 hours ago, ords said:

That's interesting to know. Mine was bought as an ex demo at 6 months old from a Skoda dealer and came with a Varta battery which is still fitted. Would it have been changed within the 1st 6 months?

Mine was - from AGM to a Moll EFB, along with the alternator.

Hi All

 

Thanks for all of your advice I'm really grateful.

 

I haven't had chance till tonight to test anything due to work.

 

I have tested the battery on cranking and on the first start the multimeter went down to 7.94 volts and then once started the battery was being charged at 14.79 volts so hopefully the alternator is working fine.

The second start the voltage went down to 9.6 volts and I checked the voltage between the positive terminal and the earth and it was close to the running voltage between the battery negative and positive so the earthing for the battery seems fine.

 

The stop start hasn't worked since I have had the car which has only been about a fortnight, I have been on a few longs runs aswell and its made no difference.

 

There's no other electrical bits connected up on the car, I have no way of checking if the battery has been coded or how old it is though.

 

It looks like the battery is on the way out, the astra that I had before in the end was getting harder to start and eventually gave out and wouldn't start at all. Is it the same with the octavia's so if I just keep an eye on it until it gets worse as its starting fine at the moment or is it likely to cause more problems?

 

There's a lot more electronics on this car compared to the astra and there similiar ages but I suspose the Skoda as it's Volkswagon running gear is more advanced, which also means possibly more to go wrong.

 

Is there any preference to the OBDeleven or the VCDS programming? As I'm not sure on which to buy but would like to change the battery myself to save some money on the garage fees and also change some of the bulbs to led's which I have read up will cause error codes.

 

Thanks again for all the replys, they have been a big help

Assuming the meter used is accurate, dropping to below 8.0 volts on start is a confirmation your battery is failing, very likely a decent battery test meter will show high internal resistance along with seriously reduced capacity.

If replacing battery, ensure the new one is correctly adapted (coded) into the vehicles BCM - either OBD (with necessary functions) or VCDS will be able to do adaptation.  

Looking like your battery is the issue. Get yourself onto tayna's website and order a decent battery. Usually arrives the next day and the coding can wait until you sort yourself out or find a local with the kit. VCDS owners on a map elsewhere on the forum.

Looking like your battery is the issue. Get yourself onto tayna's website and order a decent battery. Usually arrives the next day and the coding can wait until you sort yourself out or find a local with the kit. VCDS owners on a map elsewhere on the forum.