I'm almost finished moving the battery to the truck into a seal battery box that I got from Summit. The kit came with a tube and grommets to vent to box outside of the trunk. My question is should the vent pickup be placed inside the box high or low? Since hydrogen is lighter than air I figured it should be high, but since the vent has to go downward to vent out of the bottom of the car, how will the gas ever out?

Maybe I'm just being to anal and it really doesn't matter, but I don't want a battery making a mess back there. TIA

While H2 is much ligher than air, it diffuses much faster too, so I don't think it'd make much difference about whether the vent is low or high. It's the sulpher componds that tend to cause corrosion; they are much heavier than air and diffuse slower, so given an easy choice I'd put the vent low. With two tubes you could get some convection flow due to the heat generated in the battery, but most systems find one tube adequate.

That makes sense, thanks!