I have a bit of a conundrum 2012 Hyundai Elantra touring car

after refueling tried the key in the ignition and all the power died. no lights no
dash no anything . was able to get a jump start, and drove it home, but after I
shut it down all power was gone again. I was going to check a few things so I
started with the obvious first thing. the battery. i removed it from the car and
put it on my charger. hmm interesting?? the charger says the battery is 95%
charged. so I let it charge for about 20 min then took it back out to the car
and hooked it back onto the car. opened the car, dome light was on and
could hear the normal bells and whistles. ok!! not sure what to make of this
but I figured I take things slow. turned the key to on, but not start yet. all the
normal lights came on the dash. waited a sec. still looked good. so I
attempted to turn it over, and everything died, again. no sound from anything
and no power. i tried to disconnect the terminals to see if maybe it might
reset the brain or something. nothing!! so I took the battery out of the car and
took it into the house, and hooked it onto my charger again. says we are at
95% no bad battery indicator.  so here in a bit I'm going to see if I get the
same result. I know signs of insanity, expecting different outcome from doing
it the same again. I'm just hoping that I might catch something I didn't before.
so my question is anybody got any clues?  oh and by the way I can't check
the silinoid, but the fuse looks good for the starter.