battery and alternator were replaced , but the charge battery system light is still on also the car is going dead
It sounds like the alternator isn’t working even though it has been replaced. The replacement may have a problem but there could be a problem in the wiring to the alternator. Make sure the fuses are good in the dash panel. Verify that power is getting to the lamp lead of the alternator wiring when the ignition is on.
The battery current sensor may be faulty.
Tester