Moll car battery at 11.79V - normal?

[Aciduzzo]

Since buying my 2019 Superb just over a year ago, i've had trouble with the start-stop functionlity. However, lately, i've also been having issues with KESSY not working. So i have just measured the voltage of the original (Moll 69Ah) car battery: 11.79V. My journeys are all very short, and i realise that isn't great for the battery, but is such a low voltage normal on a two-year old battery? 

[Jase_31]

I have an Exide 096 battery (EFB) that I think was original out the factory, about 30months old.  Im getting 11.0v to 11.7v when measured in the morning after standing overnight. Sometimes I get low battery warning. Skoda claim the battery is fine, but I am not so sure?

 

Can a charger (like a ctec) be put on whilst still connected to the car? Is I disconnect does it cause issues (Superb 2018) 

[Warrior193]

Hi Jase, charging with battery still connected is fine - charger + to battery post, Charger -ve to tag on firewall bulkhead (important) 

Note to 1st poster - that battery is pretty well discharged, probably from the short runs. I'd invest in a reasonable smart charger to see if that helps. The automatic stop-start and regenerative battery charging systems really do not like short trips, especially as the alternator doesn't fully charge the battery!  

[Aciduzzo]

On 11/02/2021 at 20:00, Warrior193 said:

Hi Jase, charging with battery still connected is fine - charger + to battery post, Charger -ve to tag on firewall bulkhead (important) 

Note to 1st poster - that battery is pretty well discharged, probably from the short runs. I'd invest in a reasonable smart charger to see if that helps. The automatic stop-start and regenerative battery charging systems really do not like short trips, especially as the alternator doesn't fully charge the battery!  

I used a CTEK MXS 5.0 to charge it, got it up to 12.7V. Next morning it was down to 12.2. That was about a week ago and i haven't tested it since. Unfortunately, short runs are all i do at the moment!

BTW, when charging i connected both + and - to the battery terminals. Is that not how it's done?

[Kenny R]

1 minute ago, Aciduzzo said:

 

BTW, when charging i connected both + and - to the battery terminals. Is that not how it's done?

No the +ve charger lead should be connected to the battery +ve and the -ve lead connected to the earth tag on the bulkhead adjacent to the battery -ve terminal.

[Aciduzzo]

6 hours ago, Kenny R said:

No the +ve charger lead should be connected to the battery +ve and the -ve lead connected to the earth tag on the bulkhead adjacent to the battery -ve terminal.

OK, i didn't know that. What i did doesn't seem to have done any harm to the battery, fortunately. 

[PetrolDave]

8 hours ago, Aciduzzo said:

OK, i didn't know that. What i did doesn't seem to have done any harm to the battery, fortunately. 

It won't harm the battery but it will confuse the battery management system on the car as it won't know that the battery has been charged.

[Warrior193]

23 hours ago, Aciduzzo said:

I used a CTEK MXS 5.0 to charge it, got it up to 12.7V. Next morning it was down to 12.2. That was about a week ago and i haven't tested it since. Unfortunately, short runs are all i do at the moment!

BTW, when charging i connected both + and - to the battery terminals. Is that not how it's done?

No, recommended method is to connect charger negative only to the flat earth-tag on the firewall bulkhead - same applies when jump-starting, either as donor or recipient. 

[Aciduzzo]

On 18/02/2021 at 08:15, PetrolDave said:

It won't harm the battery but it will confuse the battery management system on the car as it won't know that the battery has been charged.

Ah, okay. In that case, should i do it again the proper way?

[BTW, about ten days after charging, i'm down to 12V]

Edited 21 February, 2021 by Aciduzzo

[Warrior193]

I give my Octavia a top-up about every two months during the winter - 18 mile round trip work commute, 3 days a week being my main mileage currently.  I use a Ring RSC608 smart charger. Battery SOC usually indicates 40-50% before charging. My battery and alternator were replaced under warranty in the first year-current battery is only an EFB. I intend to replace it with an AGM when it dies - and get the change coded.  

[PetrolDave]

19 hours ago, Aciduzzo said:

Ah, okay. In that case, should i do it again the proper way?

[BTW, about ten days after charging, i'm down to 12V]

Just do it the proper way from now on, it will take more than one charging for the BMS to correct its view of the battery SoC but it will get there.

 

BTW since lockdown 1 last year I've been using a 15W solar charger from Amazon plugged into the 12V socket in the centre console - start/stop works within a couple of miles of leaving home (when allowed out!) and the battery voltage never drops below 12.6V

Quote

SARONIC 15W 12V Car Battery Charger

 

[SkodaNor]

I wanted to ask about this and might as well do it here.

I got an MY19 Kodiaq, AGM 68Ah battery. Earlier in winter I got a warning that the battery voltage was low, which wasn’t too surprising with-10C, short trips and use of Webasto.

 

I recently had a two year service and was told the battery was quite low. I measured it to 12.1V myself and after letting the service centre charge it, it’s now 12.5V.

 

This period had also been cold (-10 to -15) and 2-3 webasto runs, but usually trips around 20-30 minutes each way. I disable start/stop when driving, but the trips often contain a few stops.

 

What the service centre told me was that I should charge the battery 3-6 times a year, even during summer because the dynamo didn’t charge the batteries completely. Not just to avoid the battery from getting too low from cold, short trips and webasto use, but because when going on longer trips, the car doesn’t charge the battery enough.

 

I was somewhat surprised by this. A car that can’t maintain its own battery sounds strange. I’ve read a bit in here about micro hybrid, the start/stop system and recovery charge, and from what I understood, maybe it doesn’t want to get the SoC to 100% without a charger. I also read a few places that the battery health might be better with SoC regularly in the 80-90% range.

 

I don’t mind charging now and then during winter and get the point, but is it really necessary during summer or times when you only drive longer regular trips?

 

When I measure with my meter, is that sufficient information to decide if I should put on some maintenance charge? Let’s say I check it every now and then and one day see that it is 12.3V, without any longer trips planned.

[Warrior193]

Hi, welcome to the forum. Charging through the summer won't probably be necessary if your trips are a bit longer - the automatic engine-stop function is probably a reasonable test for battery SOC ( if it disables itself, the battery would certainly benefit from an external top-up) Do you own a 'smart charger'?

Testing with a multimeter will only give a no (or low-load) battery terminal voltage unless you test with the lights, etc. switched on - to test battery condition properly requires a high rate discharge voltage test which measures the battery voltage while running a pre-determined load.

Do your cars in Norway still have the battery SOC function in the Maxi-dot display? Skoda removed it from UK vehicles sometime around MYs15-16.

 

Re. your Webasto auxiliary heater, I wish that was available as an option here in the UK.  

[SkodaNor]

Thanks. The start/stop function has been working, and I have never had issues starting the car, but a battery voltage with no load at 12.1 V seems quite low. Would be interesting if I took a long drive before it was charged to see what it got charged to.

 

I know that to do a proper capacity test you need a load (I’m an electrician), but it’s not so much the current health of the battery that I wondered about. It was more about what to expect from the charging it gets from the car and if a top-up now and then is advisable, even if driving pattern and temperature would suggest it wasn’t necessary. With the recent weather and use of the car, I can understand the need for a top-up.

 

I had a charger that I used on my old car a few times, but not sure if it’s still around. I don’t have easy access to a socket to charge from (3rd floor in an apartment block), so I figured it was just as easy to let them charge when I delivered it for a wash. I might get a charger, at least if we buy a house.

 

I haven’t been able to find the battery SoC or voltage in the menus. I got the digital instrument panel (really happy I added it).

 

Love the webasto. Especially since we can’t use a Defa or something similar. I don’t mind a cold car that much, the seat and steering wheel heating is quite effective, but it’s great for hauling kids that they don’t need thick jackets or layers of clothes that compromise safety. The best is getting an ice free car in winter. I also got the heated windshield, so it doesn’t take too long to de-ice from a frozen state, but a pre-heated, ice free car is great.

[gregoir]

I've got a voltmeter cum USB charger plugged into my 12V socket. The stop start was working well. I noted the voltage dropped quickly to 11.9V at a traffic light standstill. Usually 14.6V indicated on the move.

[PetrolDave]

28 minutes ago, gregoir said:

I've got a voltmeter cum USB charger plugged into my 12V socket. The stop start was working well. I noted the voltage dropped quickly to 11.9V at a traffic light standstill. Usually 14.6V indicated on the move.

I see the same voltages with a voltmeter in the 12V socket. When driving you can tell when the battery is "fully charged" as the voltage drops from 14.6V to 13.2V.

[Aciduzzo]

On 22/02/2021 at 11:22, PetrolDave said:

 

BTW since lockdown 1 last year I've been using a 15W solar charger from Amazon plugged into the 12V socket in the centre console - start/stop works within a couple of miles of leaving home (when allowed out!) and the battery voltage never drops below 12.6V

 

Just got my Superb back from the Skoda dealer. I asked him about these solar chargers - he said they don't work that well with 12V sockets because these sockets are intended to deliver power from the battery rather than supply it with power. He said the old cigarrette lighters work better for charging purposes. No idea if he's right - i will probably still get that solar charger and test it myself ! 

 

Otherwise, for anyone that's interested, they said there is no issue with the battery (which they measured at 11.7V). The KESSY issues were rectifed by simply changing the key battery. I never thought the key battery needed to be changed because the key had no problem opening/locking the car, even from a substantial distance. However, apparently, when you lock/unlock the car with the key, the key only needs to send a signal. But, with KESSY, the key needs to receive a signal as well. And that requires a higher key-battery voltage.  

[PetrolDave]

15 hours ago, Aciduzzo said:

Just got my Superb back from the Skoda dealer. I asked him about these solar chargers - he said they don't work that well with 12V sockets because these sockets are intended to deliver power from the battery rather than supply it with power. He said the old cigarrette lighters work better for charging purposes. No idea if he's right - i will probably still get that solar charger and test it myself !

Well it works really well for me - before I had the solar charger the battery voltage would be down to 11.6V after a month sitting doing nothing, but with it the battery voltage was 12.6V under the same conditions. So my experience is that the solar chargers DO work despite what the person at your Skoda dealer said.

[Breezy_Pete]

15 hours ago, Aciduzzo said:

No idea if he's right - i will probably still get that solar charger and test it myself ! 

Good plan, sounds like BS from whoever said that about the 12V skts, unless they are only live when ignition is on.

 

[PetrolDave]

2 hours ago, Wino said:

Good plan, sounds like BS from whoever said that about the 12V skts, unless they are only live when ignition is on.

Which in the UK isn't how they are wired on VAG cars - they're always live (but I understand that in some other countries they can be changed to ignition switched just by moving the fuse).

[Breezy_Pete]

7 minutes ago, PetrolDave said:

Which in the UK isn't how they are wired on VAG cars

Mostly, yeah, but I have very limited knowledge of recent cars.  Citigo is/was an exception to this, I believe.

Edited 12 March, 2021 by Wino

[J.R.]

If the Skoda dealers lips were moving then it was BS, if not then you imagined it.

 

Either way the statement simply isn't true and does not even make any sense not that they would know that.

[PetrolDave]

18 minutes ago, Wino said:

Mostly, yeah, but I have very limited knowledge of recent cars.  Citigo is/was an exception to this, I believe.

All the VAG cars I've owned since 1999 (8L S3, 8E S4, 8E A4, 8E S4, 8E RS4, 5E Octavia) have had permanent 12V sockets - which I find really useful when taking a coolbox on holiday.

 

One of the first mods (if not the first) I'm going to do on my Toyota Aygo when the weather allows is to change the 12V socket from switched to permanent (and fit a much bigger battery!).

Edited 12 March, 2021 by PetrolDave

[cheezemonkhai]

On 12/03/2021 at 11:37, J.R. said:

If the Skoda dealers lips were moving then it was BS, if not then you imagined it.

 

Either way the statement simply isn't true and does not even make any sense not that they would know that.

 

The flow of electrons requires a circuit, so that they go from +ve to -ve.

So that old it's not suitable for charging, but it is for supplying is a bit of a joke.

Perhaps they relate to the max current, but as long as you're only trying to stick 5-7 amps down it it will be fine.
Trying to fast charge at 20A through the lighter/12V socket would just be asking for trouble anyway.

 

I regularly charge via the boot socket using a ctek and have no issues.

 

I have to say, I thought there were problems with some of the MOLL batteries in some cars and that people were just replacing them with larger capacity (possibly 096) varta or similar batteries.

[Aciduzzo]

Quick update having bought and used a 10W solar charger for about ten days now: it's made no difference! Upon opening the bonnet and connecting the voltmeter i get around 11.8V. Keeping it connected for a while results in an slow increase up to about 12V. But that's it - far from good enough for start/stop. Do i need a more-powerful solar charger? @PetrolDavesaid he's getting 12.6V with his.

 

BTW, charging with my CTEK gets the battery up to 12.8V, but, by the next morning, it's already down to 12V. As i said before, however, the dealer said the battery's fine. Any ideas, anyone?