They do have this. When I bought a new battery from Kwik Fit, there was a blanking plug on each end. I removed the one on the left and connected the tube to the hole in the floor...you should do this to vent the explosive gasses.@ Kajtek1 I flew back home last night from a mini break to find a new meter waiting, so bee out this morning to check.
Before starting the car it was reading 12.33
As soon as I started the car it went to 13.97
and was slowly increasing after around 2 minutes it had gone to 14.03 where it seemed to settle.
@ magna steyr I dont have this battery, nor did the one which I removed, I also have 2 friends with E class and neither of them have this type of battery fitted, I have just had a look and I can see where a exhaust pipe would go, however this has a blanking plug over it, I am wondering if UK spec cars have this tube
everything is now bone dry