I own a 2011 Skoda Octavia 2 litre Tdi auto.

some weeks ago I started to hear this low bong noise through the front speakers. It’s not anything to do with lights, or temperature.

It sounds when the car is locked and unoccupied, and at any time of the day, and also sometimes when it’s first unlocked ,

no warning alerts show on dashboard.

some past quotes have suggested it’s a low battery warning, but the battery still shows the black colour on the battery panel.

the bong stops after about 3 or 4 times

I would check the battery with a mulitmeter those indicators on the top of the battery aren't always very accurate in my experience   

1 hour ago, seriesdriver said:

I would check the battery with a mulitmeter those indicators on the top of the battery aren't always very accurate in my experience   

I will agree!

Sounds like a battery low voltage warning .... I used to get something similar on my Citroen C5 

It is the little black cube sitting on top of the dash in front of the windscreen. I had  it a couple of months back and someone told me what it is, but I have forgotten. Some sort sensor.

I doubt the sunshine sensor would cause a warning sound.

Thanks for all the comments. In the last few weeks the bong ceased without me doing anything, but last week sound just once.

battery tested today but only 65% efficient, so new one installed .

hopefully this is the end of the matter.

 

I had a similar bong warning when I was waiting on an airfield for 90 minutes or so with the radio on and engine off.

As well as the bongs, the message scrolling across the display screen was something like "Please turn on the engine to recharge the battery."

Note that the radio turns off automatically after after 60 minutes but you can switch it on again.

1 hour ago, Hood said:

Thanks for all the comments. In the last few weeks the bong ceased without me doing anything, but last week sound just once.

battery tested today but only 65% efficient, so new one installed .

hopefully this is the end of the matter.

 

Wise move at the last service my trusted local garage said my battery was at around 65% of original cca and within two months it did fail to start the car one morning.