When driving along at speed things are ok, but when slowed to around 10mph or less (low revs) the headlights (dipped or full) go funny.

Dipped will dim very slightly when the steering is used when manoeuvring.

If the rear heated screen is on too then the full beam/dipped would flicker when going very slow and turning.

So bearing in mind the slight dimming of the dipped beam has been noticeable for a while and got better in the summer I'm thinking knackered battery.

My only issue is that you used to get far more than 4-5 years out of them in the old cars, but I guess with all the electrics the newer cars kill them quicker.

The other thought I have is maybe the power steering pump is mad, but it was replaced probably 2 years ago for an issue with it.

So anybody any thoughts on this, even if they are just a case of yep, go get a new battery.

If things were more stable I'd be up the Merc or BMW dealer for a new car, however bearing in mind they're not I guess I'll have to give it a check the other options :(

Do halfords offer a free battery test as I've got one near work so can get them to test it for me then find the correct battery.

I wonder if it's worth topping the cells up with deionised water and charging the car battery.

I,d put my money on the battery for sure.

Halfrauds will only do a "Drop test" on it meaning putting it under load on car with a machine that reads the voltage under full load.

and I'd put my money on something a little more fundamental than a battery - voltage regulator perchance? Iffy alternator?

Needs more diagnosis than your average spanner monkey at Halfrauds will be able to do. IMHO

Right well I had a look at the battery in the light and the eye on the top is black.

So question is are the skoda batteries a "black then go red" or a "green and then go black" type?

The modern batteries are "sealed" but often you can get to the cells to check/top them up.

FWIW, the power steering pump can pull a huge amount of current (I remember reading 60A somewhere), so it might well be that the battery doesn't have enough to smooth it when other things are on.

Does anyone know the output for the alternator on the octy II TDI?

The battery is certainly something that's worth testing and don't worry about me buying a battery from halfords at full price, it's not going to happen

I'll run VAG-COM across it tonight then.

If its an Octy II it definitely isn't problem with the power steering pump as there is none. There's an electric motor for power assistance instead. This motor will draw a lot off the battery compared to what the engine is topping it up with while the engine is idling, so definitely check battery/alternator first.

If its an Octy II it definitely isn't problem with the power steering pump as there is none. There's an electric motor for power assistance instead. This motor will draw a lot off the battery compared to what the engine is topping it up with while the engine is idling, so definitely check battery/alternator first.

Was my thinking too

Does anyone know if the eye is green to black or black to red as mine is showing black.

Also I don't suppose anyone could tell me the current rating for the battery that's in there.

The options I have so far are 680W/66Ah (Halfords calcium) and 780W/77Ah (Bosch Silver)

Definately Green or Black no Red in the standard fit batteries

According to my manual:

Green colour - Adequately charged

Dark colour - Battery has to be charged

Colourless or yellow colour - have the battery checked by a Skoda garage

Ok well the thing is black or possibly clear as the black ball doesn't seem pressed right up against the lens.

I popped over to the halfords at work where they used a bosch hand held electronic tester, which read out at 12.89V, the alternator was apparently showing 14v at idle and the battery had 92% of starting capacity. (Not quite sure how that last one is worked out mind)

I've noticed mine says 61Ah 330A 580A.

After this i did a bit more research and found i can get the lights to flicker if I have the main and dipped beams on, the heated rear screen on and the steering used at low revs.

If I take the main beams off, then the lights just dim a small but noticeable amount when using the steering, but this happens with or without the rear heater on.

So questions I have are:

- How much power can the steering assistance pull, is it really 60A max?

- How much power can the heated rear screen pull?

What would the halfords tester have shown, and does anyone know how to get into the original battery to top up the cells so I can try a charge or is it actually a sealed unit apart from some vent pipes.

I checked out the tester used and it's a non-load tester.

Does this mean it doesn't place a load on the battery or that it's for testing when the battery isn't under load.

I'm guessing the first is a bit pointless as obviously a battery might be just fine until you pull a sustained current from it at which point it might not be able to deliver.

Sounds like the halfords techie stuck a volt meter on the battery. The load the power steering can place on the battery is indeed 60A, especially at full lock.

My lights flicker ever so slightly, but I only notice it when parking in the garage at very low speed.

Sounds like the halfords techie stuck a volt meter on the battery. The load the power steering can place on the battery is indeed 60A, especially at full lock.

It was one of these:

Bosch Test Equipment Accessories, KTS 520 - the multipurpose solution

My lights flicker ever so slightly, but I only notice it when parking in the garage at very low speed.

Yeah mine didn't do that, then i noticed it most of the time. The reason i got a bit worried was the dipping while i was on road and moving around.

I'm thinking that if I change the battery a Bosch/Varta silver (Same battery) 780A, 77Ah one would give a bit of breathing room over the normal capacity. The only slight queery I have is with this being a silver/calcium technology battery, how is that going to fare on the alternator compared to the lead acid one and is the OEM one just a vanilla lead acid.

It's by some make beginning with A that I've not heard of before, which is never a great sign.

Thats not a load tester they used just a voltage tester.Fairly basic checks.Its best to have it load tested then it will show its weak point immediately but may also kill it in the process.

Going to a bigger output battery will do no harm at all.I checked my PAS when parking and my lights slightly flicker too.

Thats not a load tester they used just a voltage tester.Fairly basic checks.Its best to have it load tested then it will show its weak point immediately but may also kill it in the process.

Going to a bigger output battery will do no harm at all.I checked my PAS when parking and my lights slightly flicker too.

The slight flicker when parking I can live with but the big all over flicker and light literally going up and down can't be good for the electrical systems.

Well kind of random, but this time it happened again and there was a clicking noise.

At this point the lights were on, no heated windscreen and I flashed another car to let them past an obstruction before me.

Getting very odd and a VAG-COM scan shows nothing. :(

Have you changed the battery yet, it sounds like its ability to hold charge is dwindling fast. I would now change it asap otherwise you could find yourself stranded.

I've been laid up in bed since this happened with flu :(

I'm intending to get a new battery on the car ASAP, but it's a bit odd as the car starts first time every time. It just seems a bit odd that the car will start without issues, but can't cope with driving.

Saving that, I don't know if the starter motor pulls 60A and the electrical steering assistance being able to pull that sounds like one hell of a load.

Later on that drive I tried it again and there was no issue in flashing the lights, so it's all weird now.

I've been laid up in bed since this happened with flu :(

I'm intending to get a new battery on the car ASAP, but it's a bit odd as the car starts first time every time. It just seems a bit odd that the car will start without issues, but can't cope with driving.

Saving that, I don't know if the starter motor pulls 60A and the electrical steering assistance being able to pull that sounds like one hell of a load.

Later on that drive I tried it again and there was no issue in flashing the lights, so it's all weird now.

My bet is the battery, the battery that was on my omega showed 12.5v once charged, but left a few days locked up. It soon dropped to 10.5volts, which after a few slow cranks was enough for it to burst into life. Everyday use it started fine.

I've had to replace the battery on two mk4 astra's, the 1st one i had was a 1.8. It was quite difficult to hold it on the clutch on a hill. The revs were up and down all over.

Had a battery tester on it and it came back "ok", once it was changed it ran perfectly.

The 2nd car was a mk4 astra coupe turbo, turning the car off and running the headunit for 15-20mins the car refused to start. Again this was tested on a battery tester and showed "ok".

I dont trust alot of these checkers, as its the capacity thats needed. Its a little like the memory effect on Ni Cad batteries.

Given the voltage readings you got and the fact that the starter is cranking well enough to start the engine fine, I'd be a bit suspicious of :

(A) poor electrical connection somewhere, which is sometimes difficult to locate. First place to check is the battery connections. Take them off and have a look at the terminals on the battery itself, and also inside the teminal connector. Look for signs of corrosion, esp white or green crud. Extra heat when you've got the lights switched on or are cranking the engine is an indicator (resistance to current flow reduces voltage and also crestes heat). Next place would be the wires going to the fuseboxes (especially the ones in the engine compartment).

( Faulty alternator/voltage regulator (located in the alternator) or alternator connections. This could lead to reduced voltage under load, but be OK other times (thus the dim lights when steering). One way to test this would be to hook a voltage meter up to the battery (where you can see it when you are driving) and see what happens when you do the things that make the lights go dim/flicker.

© A fault with your headlights, possible a dodgy fuse or loose/corroded connection (or even a faulty controller).

(D) You are sitting idling a lot with the lights (and other electical loads) draining your battery. Modern alternators are very good, but they still need the engine revving (ie above 1,500 rpm) to generate their rated output. A battery is like a bank account, you need to replace what you are withdrawing or it will run out of what you want.

Low voltage can seem to create havoc with the controllers VAG uses these days to do almost everything on their cars, I've read many reports of all sorts of weird problems that turned out to be caused by low volatge in/to a controller.

Have you checked to see if any faults have been stored (using VCDS) ?

Yeah, the only problem I have showing on VCDS is an intermittent cruise control stalk (the headlights are also on this mind).

This only showed after things started going mad, however the fault is posted below:

18104 - Powertrain Data Bus: Implausible Message from Steering Column Controller

P1696 - 000 - - - Intermittent

Freeze Frame:

RPM: 2394 /min

Torque: 50.0 Nm

Speed: 125.0 km/h

Load: 20.0 %

Voltage: 14.21 V

Bin. Bits: 11001000

Bin. Bits: 00000000

(no units): 1.0

So the voltage shows high enough there, which is a bit random.

More suggestions welcome as I'm going to put a battery with a higher rating in otherwise (780A 77Ah vs 610A/61Ah) which should allow the battery to smooth over higher demands a bit better if case (D) applies.

It's not the battery. Like I said before, dodgy alternator or voltage regulator but I doubt very much its the battery. Find a vehicle electrical specialist near you - Bosch centre or something and let them look into it. Don't waste money on the battery until you are sure its really that...........which it isn't IMHO!

I'm with Wardth on this. I'd want to do some proper testing to find out what the problem really is before I spent money replacing what might be a perfectly good battery. Otherwise you might end up with a brand new, high capacity battery but still have your flickering lights.

I read up on your 18104 error code and it was pointing towards a possible fault in the wiring for the power steering. If there is a short or some other fault in the power steering electrics that caused it to use a lot more power than it should be, that might make your lights flicker (due to the resulting low voltage).

The 18104 is usually caused by a dodgy cruise control stalk from what I've read and I've already had the other stalk replaced. Do you have any links as I'd be interested in seeing what was said to try and find out more.

I did have the alternator voltage checked and it was showing 13.9-14.2V (At battery terminal) which seems about right to me.

I took the old battery out and found the covers for the water and checked all of these. All were fine in terms of water level, but the lead plates were white and hard with some odd almost furry coating around a few bits.

I put it on a charger and the thing went from around 50% to just fully charged inside of 2 minutes.

All seems a bit odd.

Something else is that I took the main beam headlight bulbs out and found one of them was 100W the other 55W. Obviously this won't have helped things, but I can't see that it should have caused the whole lot to go mad.

The car was fine with 2*100W in there when driving abroad, but I've got 2*55W +30% bulbs to go in there and see what difference it makes.

Edited 5 October, 200916 yr by cheezemonkhai

That sounds like lead sulphate and is sign that the battery is about to go for a long holiday to the recycling centre.