Can,t get into 525i with key because battery died

Sounds like the battery in your key fob died. Just replace the battery. The new transponder fobs require the key to prevent the car from being hotwired or someone just popping the ignition.

Check your fuses under the hood. Check your manual or on the cover of the fuse box (inside/on top) for location for climate control and check for a bad relay or fuse

Combination of brake and battery light mean the alternator is not charging. after you wait for a wile the battery recover some power and will run again but as soon the power drop below 9V the engine die. Test the charging system and replace the alternator
Good Luck

Have you found the fuse box, under the bonnet on LHS of vehicle?
In the lid of the fuse box it will outline which fuse controls the function.

Do not believe it should stay on. Does it stay on even after you open the door and remove the key? Does it ever go out? Let me know and I'll try and help

You will have to get into the hood manually to jump the battery and the use the key less entry. Use a long flathead screwdriver and pop the hood latch. To do this simply push the latch horizontally with the screwdriver and the hood will pop open. Jump the battery and you will be able to get into your vehicle. I would then address the reason your battery dies if not replace it.

Assuming you replaced the solenoid with the starter, it may be the relay. If the relay is not making a good connection, it might have trouble throwing the solenoid. The relay should be in the relay box under the hood. You can break the relay open and watch it work while someone turns the key to verify the problem.

use the key in the lock cylinder on the drivers door.

my car is the same way, so I only use the trunk lock ........to lock/unlock vehicle.....no more problems.........

what i would do would be to try and jump the car by popping the hood and connecting the jumper cables to the jumping post under the hood. there is a positive , and what you need to do is just ground the negative to something metal(not engine block). this is located close to the front left corner. email me if you dont understand. i will try to explain better. [email protected]