Your battary is death for sure it will not hold the charge that why ...

check make sure you battery cable is clean and have a good connection...

question why is your battery go death.. bad alternator ??? that why it wil not charge the battary ???

or battery just to old and dry death .. can not hold chager any more....

1. first thing first replace the battery...

if the problem come back than check your alternator...

oftend it can be a bad ground..

NOW you can have something electrical short out and drain your battary when you part the it happend to me .. check your dome light, trunk light , often time glove box light , stereo some time these thing stay on and drain the battery....