Checked my 'maintenance free' OEM battry on my Octavia today. It's just over 3 years old.

The instructions on the label on the top near the magic eye thingy say something along the lines of 'black OK, clear replace'.

Now, I can't remember what it looked like when it was new, but now it's neither all black nor all clear. It looks like a black central spot, a clear ring, then a black ring around the outside.

Any one checked their battery lately? Did the 'magic eye' look all black?

The battery looks like it has access to the cells if the sticker is peeled off the top. You can feel a plug for each cell under it. Any one pulled the sticker off and done a top-up on one of these?

It's usually the central spot you need to look at and if that is black then all shoud be OK. The viewing glass can never be totally black as the black spot you see is the top of a float within the battery that is in the electrolyte. The clear ring is the liquid around the float...

Thanks a lot skomaz! Much appreciated.

Never knew that, I always thought the center spot should be green even though mine never was

Yes, some are green and they change to yellow when the battery is knackered. Had one like that on my old Astra. Others like on my Octy go from black to clear. Depend on the battery make.

Bare in mind the indicator is only connected to one cell, get a proper battery check before you you condemn your battery.