Help. No power to car...

[belo]

So after a week of sitting my 02 mazda protege5 would not power up. nothing, not even a slow crank or interior lights.

so i figure its the battery. hook up the charger/tender and it flashes red (not connected properly). i disconnect the battery from the car and the green light flashes (battery 80% charged). huh. so i clean up the terminals with some battery cleaner (there was some corrosion) still nothing.

i bust out the voltmeter. power from battery to fuse box. all fuses and grounds appear to check out. im stumped. the batteries old, the wires/terminals are old and dont look great but if it holds a charge by itself it's good right?

there is no aftermarket alarm. i'm stumped. anything im missing or should try? how do i test relays?

 

[bazooka joe]

i don't think 80% is enough

 

[belo]

maybe not, but i should still get acc power and a slow crank. i get nothing. going to test the battery at autozone today. thinking it could also be the ign switch...