Charge by driving. Was the unexpected message as I moved the car on the driveway. I guess this has some connection with the lack of STOP/START function recently. 48 mile return trip tomorrow anyway. We'll see.

Perhaps you need to have the have the battery or it's connections checked!  you need to find out why the  "Charge by driving! info is there!

AGM batteries now fitted are unlike previous batteries from the past, High current is required at any moment in time, due to the demand of the stop/start feature, and require special attention not to drop volts below 9 I believe, a replacement AGM battery for stop/start vehicles are extraordinarily expensive to replace.

 

I learned this as I had left a dash cam on in the vehicle for 1 week (holiday break) and came back to an almost completely dead battery and I was unable to re-charge the battery with a standard battery charger, The vehicle would not start with a jump start either.

Fortunately a industrial high current battery charger brought the battery back to life overnight, but it was quite worrying.

 

The car was serviced 3 weeks ago and the battery and alternator were checked as part of my complaint that the STOP/START system was not working.

A few pointers...

Loss of stop start function is the first indicator that the battery is not being maintained at full charge.

Most common reasons:-

Frequent short trips locally, with or without all the electrics running.

Gadgets permanently plugged in and drawing off the electrical system.

Infrequent use, parked up for a few weeks at a time.

Low annual mileage

 

Cold weather will show up a weakened or internally damaged battery as the chemical reactions inside are naturally slowed down due to low temps. might get a slower than normal engine crank or non start in this case. Battery companies make more money in winter! Colder the better!

AGM's tend to operate around 12.8v. If they are held in a discharged state for a few days, sulphation occurs which can become permanent if the battery is not fully charged soon. You loose performance as a result and the battery will discharge quicker than you expect in the future. The more days they are held discharged, the more permanent damage is done.

Below 12.4v is discharged. Should still be able to start the car. S/S inhibited around this point.

Below 12.1v is deep discharged. Might not start at all. Internal battery damage starting to take place that may not be reversible if not charged very soon.

Below 11.8v Holy carp! Get it on charge quick!

 

AGM's are designed to take the high discharge/recharge cycling imposed on them by the stop start function (frequent use of the starter motor) and high electrical content on high spec vehicles. A comparable standard flooded battery will still work in the same car but it will fail through wear sooner than an AGM. Flooded can have around a 50% life expectancy of an AGM. Repeated deep discharge/recharge events with a flooded battery can also cause water loss and eventual explosion.

 

Repeated use of a recon function on a charger can also dry out a battery causing an early life failure. It causes batteries to gas a little each time it is used. This is water being split into hydrogen and oxygen. Too much of this and you loose water volume as the gas is vented off and is not allowed to recombine back to water in the battery. In an AGM as there is no loose electrolyte available as in a flooded wet battery, therefore a lot less water present to work with!

 

If you buy an aftermarket AGM, make sure it has the same or higher Ah and CCA rating on it.

 

 

 

 

Thanks for the comprehensive reply. My mileage is pretty low nowadays and I rarely go on long journeys. Watch this space.

Battery (Yuasa) is £168 fitted at Halfords with 4 year guarantee. AA will fit a battery for £199.

~£300 at Europarts with a 3 year guarantee.Gulp.

Edited 15 November, 20178 yr by gregoir
Additional information

Just done a non stop 80 mile trip on M1 with no window heaters, heated mirrors or headlights on. STOP/START is still not working.

Must contact the dealer for another bit of discussion. 12.1V with ignition off.

Edited 19 November, 20178 yr by gregoir

Do you use engine braking much? That seems to be when the battery gets a lot of its charge.

Not sure what you mean. But I do use the gears to slow down when appropriate . Cruising on the M1 today got me 54.5mpg indicated. 

First thing in would do is charge the battery with a decent AGM compatible charger. I use a Ctek one. 

Gregoir,

 

Just ran a quick test on mine as a comparison. I get 12.1v after the car has been unlocked, doors opened then closed (No ignition or engine running). After locking it back up, its taken 5 mins to get to 12.55v, 15 mins to get to 12.59v, At 30 mins, 12.60v. Unlocking dropped the voltage straight to 12.0v.

 

There seems to be a bit of an offset of around 0.2v between voltages with the battery when in a connected state or disconnected state so in this case it might not be the battery causing s/s to not work. There are a heap of electrical parameters that need to align first for it to operate. If its cranking as quickly as ever and starting up cleanly, I wouldn't worry too much at the moment. The only thing a dealer can do is check it with a Midtronics tester to get a result. If the figures are OK, theres no point changing the battery.

 

Also if its been recharged recently and the positive lead was connected direct to the battery terminal and not the other side of the little black battery minder, the battery may be OK now but the minder thinks it isn't as it 'hasn't seen the charge enter the battery', so to speak. So many if's and but's...!

Being looked at next week. I'd have hoped  the STOP/START would be working after 85 miles. SWMBO Getz has a 3 yo battery with 12.4V after only local runs.

Today did a further 180 motorway miles at 56mpg, on headlights as it was wet and murky. The STOP/START was surprisingly working when I first stopped in suburbia, then stopped again when I got nearer home after a few STOP/STARTS. Will check the voltage after an overnight rest.

15 hours ago, gregoir said:

Today did a further 180 motorway miles at 56mpg, on headlights as it was wet and murky. The STOP/START was surprisingly working when I first stopped in suburbia, then stopped again when I got nearer home after a few STOP/STARTS. Will check the voltage after an overnight rest.

I wonder if your battery management system is confused about the state of charge of your battery?

 

Just a thought to maybe try - using VCDS (or similar) charge the battery serial number in the battery management module to any other number than what it currently is - this will make the battery management system think you have changed the battery and make it relearn the state of charge. At your own risk of course...

SWBoy is right with his thinking!

 

If an AGM battery is replaced then the replacement battery Serial number must also be changed in the "Battery management module", in your case I would do as SWBoy suggests.

This may cure the issue you have.

 

Of course you would need access to a VCDS kit

The car is under warranty and is at the dealer as I type. I mentioned about a battey reset and "that is one possibility sir".

Free coffee until I warm up.

 

No problems diagnosed  with car.  So now on my way to Skoda so they can explain why STOP/START does not function in daytime after 90 miles with nothing switched on or plugged in. Any intelligent questions that I can ask? 

Edited 28 November, 20178 yr by gregoir

15 minutes ago, gregoir said:

 Any intelligent questions that I can ask? 

Have they tried changing the battery serial number? - to force the battery management to reset its charge state parameters.

All parameters are Ok. The car was run in a warmer ambient i.e. the workshop and the system functioned. I learned that that the battery temperature, car internal and external ambient temperatures can stop the system from functioning. Battery is fine and the charging module is working OK. The battery will not charge up to 14V, when travelling along on a steady cruise, a surprise to me, but the alternator mainly charges when the brakes are applied or engine braking is used.

The system did activate once when I used the brakes to stop at a large roundabout. Am  satisfied with the state of my car but I'd like the STOP/START to work more often in 'normal' weather conditions.

My car was washed and I had a free cuppa. Will I be extremely satisfied? No, but pro tem, contented.

Edited 28 November, 20178 yr by gregoir

All parameters are Ok. The car was run in a warmer ambient i.e. the workshop and the system functioned. I learned that that the battery temperature, car internal and external ambient temperatures can stop the system from functioning. Battery is fine and the charging module is working OK. The battery will not charge up to 14V, when travelling along on a steady cruise, a surprise to me, but the alternator mainly charges when the brakes are applied or engine braking is used.

The system did activate once when I used the brakes to stop at a large roundabout. Am  satisfied with the state of my car but I'd like the STOP/START to work more often in 'normal' weather conditions.

I reproduce the parameters listed in an earlier post,

 

http://www.briskoda....-and-stopstart/

 

seems to cover most of what I was told.

 

My car was washed and I had a free cuppa. Will I be extremely satisfied? No, but pro tem, contented.

On 22/11/2017 at 17:46, gregoir said:

Today did a further 180 motorway miles at 56mpg, on headlights as it was wet and murky. The STOP/START was surprisingly working when I first stopped in suburbia, then stopped again when I got nearer home after a few STOP/STARTS. Will check the voltage after an overnight rest.

Sounds like it's working as it's supposed to. Stop worrying about it and just let it do its thing. Why do so many people seem to think they need to keep topping up the battery?

I think you have missed the point of this thread Rodge

This thread started off with "Charge by driving" shown on the display! However if you read further this has not been successful.

This has been quite an interesting read and a learning curve for those interested.

I thank "Gregoir" for enlightening us with his experience and other members which have contributed some very informative tips!

I also agree with you that it may been working as it should, however without asking other members here for there opinion / advice then no one would learn anything from it!

Here I am in November 2018. Same problem, same display. Several diagnoses since last year. The fixes did not work.

When you go on to the stop start info from the car page on your infotainment screen, is it giving you a message as to why it isn't enabling stop start.

 

When I'd got my car back on the road, I'd forget to plug in the battery sensor cable (on the negative terminal) and it kept coming up with 'engine needs to be running). Plugged it back in and it worked to work.