Dead Battery?

[drifting-pride-4-lyf]

Hey Guys,

I Have No Idea What Has Happened.

i put a new speaker in this arvo, i left the car come back 2 hours later, nothing that requires power is working, lights, locking, sterio, all the fuses are still good i replaceed the battery on my central locking. Guys Could this be a dead battery? any help would be great will save me some money from the nrma...

[Moodles2]

Disconnect the positive and ground terminals off battery and give them a good clean, and give the battery posts a good clean too then put them back on.

Where the battery is grounded to the chassis, take it off and give it a clean too make sure it's got a nice clean earth.

Run a multimeter across the battery terminals, less than 12v it's likely that it doesn't have the volts to power your things.