i have an e60 520d and last night it wouldnt start, lights wouldnt come on etc,

i pulled a few fuses and left it and it started,

this morning it started, drove a while, got home and it wouldnt start, AGAIN

tried everything, had over 12 volts at the battery, alternator, starter etc and wouldnt start, doesnt even try to turn over

had a mate come round with his car and tried to jump start as by this point a low battery warning came up on the idrive

anyway still wouldnt go, went to remove the battery ant noticed about 3" of water in the battery well,

i removed the neg terminal and left it 10 mins and it started again!

i should point out i have daylight running lights and it does around 3000 miles per year and iv had it 2, does this sound like a battery problem or something else?

the battery is off the car now and on charge untill tomorrow night,