It usually means the the alternator is going out. Go to a local autozone or other parts center and get it tested.
brake light and battery light is on
how to change a brake light on 2002 Nissan altima
low brake fluid
It's probably your Alternator that is going bad. That is if the battery and brake lights came on at the same time.
no if your battery light is on and the brake light on then your alternator need to be change
According to the owners manual for Nissan Altima 2007 it is DOT 3.
Most likely not as those 2 models are total different generations.
how to change the brakes
The Nissan Altima has an opaque cylinder that holds the brake fluid. Looking on the side of the cylinder, check the high and low marks and make sure that the fluid is between the two.
Any DOT 3 Brake fluid
well, this is what my mechanic told me when i had this problem (still have it) with my 1994 Nissan altima: the altima's alternator isn't working well. so, the battery isn't well supplied... Solution: replace the alternator immediately or dont drive the car until u do so less you make things worse. bajah
http://www.paulstravelpictures.com/Nissan-Altima-Rear-Brake-Light-Bulb-Replacement-Guide/Nissan-Altima-Tail-Light-Bulb-Replacement-Guide-011.html here you can see every step to that question.. I just did it.. and works :) by Paulo Fernando!!