ya everything in my car works fine lights stereo everything else.. so how would battery tender work? i am thinking it might be the starter.. but then i am not sure..
A battery tender just keeps the battery charge maxed but it's main use is for Boats/RV's/Stored Vehicles that sit for a while without being used hence the voltage is draining from the battery. You could try it but I would think that just getting the battery voltage tested and measured would be adequate to tell you whether your battery is dead/dying.
a battery tender can recharge a battery if its dead, but if the battery was damaged it wont be able to charge it. just run to advanced auto or w.e you have around you and get the battery tested.
that "click" is the starter relay, if the battery is fine than when the relay clicks over and gives the starter juice, if your battery turns out ok you can try smacking the starter while someone turns the key.
also when you turn the key do your lights dim and flicker and weird stuff like that?