Looking for a replacement for an oe battery for 2011 sl550, the accessory battery in the trunk. I see that it has a vent hose on one end that vents to the outside. In looking at replacement aftermarket batteries, I am seeing a vent hole on each end of the battery. My question is, if I use the vent hose in one end of the battery, does it also vent out of the vent opening on the other end of the battery?

 

Yes they battery will vent out of both sides. You can pull the small plug out of the old battery if its an OE replacement, and plug the new hole or you can simply leave it open. If for some reason the battery starts to fail or gets into an overcharge situation, you can definitely stink yourself out of the car with the fumes that will come out if not plugged and vented