need help with car problem

i have a 91 735i and today while driving in the digital info area in the dash i got a message that said "brake light circut"
then the low fluid and abs lights cam on but everything was dim. i gave it gas and everything got brighter . i then let off the gas and the car died and battery had no power. hooked a jump box to the battery and all was ok... anyone have any ideas?

alternator maybe?

the info display thing has me wondering though. the whole brake light circut thing ...all the lights brake lights work

any help would be appriciated.

I would say your alternator is probably stuck in the open position and sucking the life out of the battery. As for the brake circuit, are you sure its the light circuit or is it the Brake Lining light?