18 minutes ago, FabiaGonzales said:

Unless you disconnect the battery monitoring connector. In which case the charging system reverts to a standard charging mode which works fine with standard lead acid batteries.

 

Connecting it when you get to the dealer for servicing or MOT and disconnecting it afterwards will keep them quiet, and the battery won't really take any harm from anything they can do to it in the couple hours they'll have the car.

 

I'm assuming that you have checked that "heavy charging on the over run" does not happen when the battery charge monitor is disconnected?

The charging on overrun is no different: it is the BCM (battery control module) of the management software that controls the limit at 75% and charging higher only on overrun. Once the sensor is disconnected, it can't tell what the battery level is at. The alternator controller adjusts the charge rate as with all alternators. It only supplies what is demanded by the whole car. 

1 hour ago, TerFar said:

The charging on overrun is no different: it is the BCM (battery control module) of the management software that controls the limit at 75% and charging higher only on overrun. Once the sensor is disconnected, it can't tell what the battery level is at. The alternator controller adjusts the charge rate as with all alternators. It only supplies what is demanded by the whole car. 

 

So not what a bog standard flooded battery would like to put up with over an extended period?  An EFB would take that in its stride - or even an AGM battery.

You've misunderstood his first sentence I think rum.  He means the charging doesn't change when on the overrun, i.e. it doesn't go up in voltage.

I'll wait and see if he comes back on that issue.

 

Seeing is believing just what sort of "cram charging" goes on on the over run in a bid to use otherwise wasted energy, I was trying to find out if anyone had removed the charge sensing lead and then went on to check what now happens on the "regenerative" braking phase.

Today I got to actually drive the Fabia on an essential journey to work to pick up my PC so that I can access all the systems I need to do my job. A 20 mile round trip on dual carriageway and local roads.

 

Having not been started for four days there were no low battery warnings and when home the state of charge was 80%. Hopefully that means things are basically okay!

11 hours ago, Fabia3iow said:

As far as coding goes I will leave that to the installers. Presumably Halfords will be able to sort that?

I wouldn't put money on that. 

 

20 hours ago, rum4mo said:

Don't ever consider buying a normal lead acid battery as they don't like Stop/Start and probably Smart/Rough charging.

I find a normal battery in a stop/start car might last 6 months before dying.

 

Thanks AG Falco

I keep hearing the term "energy recuperation" on this thread. Can someone clarify what this is on the 2016 Fabia? It's not energy taken from braking is it? Didn't think Fabias were that fancy?

Correct: there is no energy recuperation or regenerative braking. 

What is being described is that the BMC module limits the charge of the battery to around 75% in normal driving by throttling the generator. When you go on a long run and lift your foot off the throttle to slow down (overrun), the BCM then removes the throttling letting the battery fully charge. But you need to drive a very long way for this to happen.

There's nothing sophisticated about a Fabia: just crazy ideas that they think will save fuel!

Or give more favourable results in EU emissions-cycle type-testing ... Always the elephant in the room.

The way I see it, the manufacturers will likely be allowed to start the test with a fully charged battery, and the 'fancy charging' system will allow it to run the test cycle without the alternator ever having to load the engine, without actively disconnecting it or anything as obviously cheaty.  Call me a cynic...

Possibly true. I know that they do ridiculous things like remove near side mirrors for the tests. I never trust anything they tell us.

@TerFar, would you mind scrolling up the page a bit to where @rum4mo may or may not have misinterpreted what you said and clarify what you meant for him?

 

Have you done the monitoring/measuring of charging voltage without the BCM connection to verify that the overrun 'spike-charging' doesn't occur?

On 31/03/2020 at 15:49, rum4mo said:

I'll wait and see if he comes back on that issue.

 

Seeing is believing just what sort of "cram charging" goes on on the over run in a bid to use otherwise wasted energy, I was trying to find out if anyone had removed the charge sensing lead and then went on to check what now happens on the "regenerative" braking phase.

 

There is no regenerative braking. When you remove the sensor, the alternator behaves like all alternators: it provides what is needed to the whole car. It responds to demand. Once the battery is full it draws just a few hundred miliamps, whilst the alternator supplies whatever is demanded by anything else (lights, fans, ECU, etc.). 

No I've not measured anything other than the voltage with a cigar lighter meter. That is ~14v.

Perfect, cheers. That measurement is sufficient.

Edited 1 April, 20206 yr by Wino

I think I may have a battery past it's best but I've been taking some readings. My battery read 12.70 volts after the Optimate 5 successfully charged it. The next day I got 12.15 volts (I'm aware systems start up once the car is unlocked so some juice lost then).  3 days later after no use it read 11.98. I started the engine and idled it for 10 mins, I then got a reading of 12.35V. The charge rate at this time was 14.98 at idle rising to 15.03 at higher revs.  To bore you further 2 days later (today) I got 11.83V  (after an engine start)  that gave 12.32V after 5 mins of engine running. I now have the Optimate back on. 

What I have learnt so far: it will start with 11.83V from the battery. It recharges at a high rate and replenishes fairly quickly. 

Once charged I will start the car and see what the charging voltage is. If I've understood the comments on here the alternator should be charging in at just over 12V with a fully charged battery. 

From my readings regarding voltage retention does anyone think my battery is not holding charge in the way it should. The start/stop lead is still attached to the battery -ve.  

Edited 3 April, 20206 yr by Fabia3iow

The trouble is, every time you unlock the car and start the engine, you will be removing considerable charge from the battery.

 

I think that you can only run checks on a previously fully charged lead acid battery installed in a car if you fabricate and install a monitoring lead that allows you access to the battery terminals without unlocking the car - I did that years ago to work out when a battery was being discharged either internally or by high parasitic drain - and do that only during a period of mild over night weather.

 

If you think that this battery is past its best, then all you can currently do is continue to keep it topped up using your external charger, then when things get back to normal, replace the battery via Skoda if it is still under warranty and still causing you problems, Skoda would test that battery before replacing though.

 

Edit:- I've just noticed that your car is a 2016 reg'd car, so not still within new car warranty, but maybe still an extended warranty?

 

There are a few online battery suppliers who should still be able to get a new battery to your door, if your car has a petrol engine, the replacement battery will be a 027 frame size EFB,  Tayna Batteries for one supply Varta Bosch and many other brands.

Edited 3 April, 20206 yr by rum4mo

You have a parasitic current problem, I'd say. Next time you charge it fully, disconnect the battery negative/earth clamp afterwards and see what voltage there is across the battery posts the next day.

I'm charging with the bonnet up so I'm not unlocking it. Also you can hear the electronic unit whir when it starts some system or other so mo whirring when I took the Optimate off just now. I didn't get to full charge this time but measured 12.90v immediately afterwards. The battery does have the red ring indicator on it so that must mean it has issues. 

Regarding removing the -ve lead.....would I not loose stored info on the infotainment system? I also inherited an activated Smartlink system so I'm worried I might loose that because I have no reactivation codes?

I have no idea about stuff in your fancy modern systems, but usually such things have non-volatile memory for anything that matters.

Edited 3 April, 20206 yr by Wino

Glass half full person... I like it👍😁

12 hours ago, Fabia3iow said:

The battery does have the red ring indicator on it so that must mean it has issues.

Moll battery - The red ring is a seal around the optic. The cell caps have the same.

 

If the engine has always started on the key, what’s the problem? 

Edited 4 April, 20206 yr by BigEjit

Thanks BigEjit. The red ring is the seal....is  that wise when it's the colour that denotes a poorly battery?  I've seen the floating green ball on some batteries that must float at a good specific gravity. Presumably something like a red ball drops on these Moll batteries.

 

You are right of course, if it starts just leave it......just like the olden days 😁

 

Btw it's great chatting with my fellow Skoda owners on here, thank you👍

Edited 4 April, 20206 yr by Fabia3iow

Are there any problems with disconnecting the battery for 3 weeks as we are going on holiday later in the year. Does it affect any settings? will the battery need re coding again?

Mike, as no one else has replied.

 

The only settings that will be lost AFAIK are the time of day clock.  If you have left an electric window down that needs resetting but is very easy, all details are in the Operating Instructions booklet.

 

No the battery will not need recoding again as it is the same battery.

 

Personally I like to also synchronise BOTH remote keyfobs (belt, braces, bit of string and chewing gum assurance) again very easy to do, all details are in the Operating Instructions booklet, but I may well be totally alone in doing this as it's not listed in any instructions.

 

I think you might have seen before me putting about alternating the use of keyfob remotes (and with key blades) to even out batteries. remote, blades and locks and so that you know that the "spare key" works and where it is..

 

I know someone (BigEjit) put in another thread how long the battery should last connected with car unused but can't remember the details.

 

If you disconnect the battery, unless I've forgotten something, the car will be unlocked.

 

Edited 28 January, 20224 yr by nta16

Hi, Thanks for that, the problem is I will be leaving the car at one of the hotels at Heathrow. I cannot afford to leave it unlocked so disconnecting the battery is out.

By the way have had no problems with the car since it was at the dealership.