Dell inspiron 1545 problem

Hello,
hi there my laptop (dell inspiron 1545)
yesterday i shut it down and today it refused to start up with the battery and thought it needed charging. i put the AC adpter it didnt do anything too. no light and not starting up.
but when i put it on an AC power adpter for vostro 19.5 volts,4.64A it did charge and start up and when it started up i tried my adpter and it charged to. what do think is the problem cause am scared when i shut down tomorrow it wont start up? help

my adpter out puts 19.5V (3.34A)