Driving back home sunday night doin about 80 down the m1 when my oil, brake and battery warning light all come on at once as well as the red warning light in the bottom right of the dash

(not sure what you call that).

They stayed on for a few minutes then went out.

Its been doin that right up till today when they decided to stay on all the time.

Also the battery voltage drops right down when they come on.

Any Ideas???