Battery voltage low

[Albourneboy]

Since last March, my car (Superb Mk3 2.0 TDI) hasn’t been needed for a 40 mile daily commute as I began ‘working’ from home. Then, in November I retired and the last decent run the car had was in December. Since then, it has done the occasional 30 mile farm shop run and the odd short journey around town. Mostly, it just sits outside unused. On Friday morning, I noticed that all four windows were wound right down. How this happened I have no idea. It was ok the previous evening. I used the lock button on the remote to close them but, unknown to me at the time, the drivers window raised, then promptly lowered again. I was unaware it was still open until a neighbour told me. This time, I opened the car and sat in it with the ignition on and tried to raise the window. This took several attempts as it kept lowering again every time it was raised. Eventually, it stayed up but then I noticed that the battery light was on and there was a message saying battery voltage low. I checked the battery with a multimeter - 11.7 volts 😳. I’ve read that AGM batteries don’t like being partially charged and if they are, they can develop a ‘memory’ which shortens their life. I suspect this may be the case with mine. 
I’ve also read that some cars need to be ‘told’ that the battery has been replaced. Is this the case with a Superb Mk3 or can I simply fit a new battery. The car is a 2016my btw. 

[Awesam]

I've just bought a 2015 Superb MK3, didnt drive for the best part of a week and the battery is flat! I think a car battery usually last about 3/4 years before they has degrading.

My new battery should here today so I will let know if I need to tell the car its a new one!

[Danoid]

You can’t just swap your battery on these cars as it needs coding in first.

 

Personally i’d wait until Monday and go for a longish drive.

 

In my mind turning as much electric gadgets off as possible will recharge the battery quicker

[Warkman]

Get a ctek battery charger/maintainer lije this

https://www.amazon.co.uk/CTEK-MXS-7-0-Automatic-Reconditions/dp/B00604UABY/ref=sr_1_2?crid=WXBSHB46C9JI&dchild=1&keywords=ctek+mxs+7&qid=1616412163&sprefix=Ctek%2Caps%2C170&sr=8-2

 

you can get a battery current condition too

https://www.amazon.co.uk/CTEK-Indicator-eyelet-practical-indication/dp/B002MT8S7E/ref=sr_1_4?dchild=1&keywords=Ctek&qid=1616412238&sr=8-4

 

then all you do us connect it when the traffic light goes red.

 

We have them fitted to all our cars, the Ctek works great

[Albourneboy]

I have a CTEK charger but it’s about 15 years old so I doubt it has an AGM mode. I’ll have to dig it out and check. Only ever used it once in all this time 🥴. I did take the car for a run on Saturday which raised the battery voltage to 12.4

[D402]

A solar charger plugged in to the lighter socket is working well for me, the car started up normally even after over a month out of use.

[Hamster59]

Funnily enough I found my superb with its windows down as well this morning, but it closed up with the key as per normal. I have found that without a small drive every other day the battery os flat enough not to start, I have the charger like the one from Amazon but only paid a much smaller price from Lidl for  a similar item, also a WiFi battery indicator from Lidl, I give it a charge once a fortnight, to top it up, and have a booster pack for when it won’t start. That’s the problem with lockdown,only local trips hardly even gets warmed up.

[Albourneboy]

Checked my charger. It’s a CTEK Multi XS 7000. Doesn’t have a specific AGM mode but the user manual does say it’s suitable for AGM batteries. It has a14.7v charging mode so ought to do the trick. Went out in the car this afternoon and it was fine - no low voltage warnings so looks  like Saturdays run was the boost it needed. Off on a 180 mile run next week which will do it a power of good. Am keeping the charger handy from now on though just in case.