[medic99]

So,

battery on my X1 was 4 years old and i decided to change it (no issues with it, just my personal preference to change batteries every 4 years or so).

Did not get it recoded by BMW.

Battery OEM part and fitted, worked with no issues for 8 weeks.

Yesterday on a long(ish) run, i noticed what looked like a jet of steam coming out from under the car (full of flu so no smell).

Popped it into the locat garage to find the battery at melting point, 'steam' was battery external vent point, mechanic would not go near it for at least half an hour until the thing had cooled a bit (still very hot with battery plastic feeling soft after 2 hours)

Alternator checked and putting out 14V but no higher.

Only thing we found was that the secont battery vent plug was still in place, would this have cased this problem?