yep that's the correct term alright....I have had two "detonations" within 3 feet of me. One was a set of 6 six volt batteries (in both occasions the batteries had just been fully discharged...and a spark was allowed to happen near the top of batteries)
nothing "explodes" except for maybe the caps go flying....but the noise is probably the loudest thing you'll ever hear in your life!....like you won't hear ANYTHING for the next 10-15 minutes! Batteries detonating is not as big a deal as it's often depicted (the Hindenburg?...not)...it is certainly LOUD and you have to buy new one(s)
yeah venting is a good idea and it's real easy
as hydrogen is FOURTEEN times lighter than air.
having said all that, a spark is NEEDED....I have run batteries unvented (like a TON of boaters do every day) but guarding against the possible production of a spark was paramount
my batteries are inside, in a box, vented AND under a dinette seat....I think that qualifies as a kind of a "belt and suspenders" thing