When you stick a new battery in and it sounds better
When you stick the battery in a battery tester and it says low
When it sounds ****ty
Quote by CowsWithGuns
And the facade of heterosexualism in the punk and ska forum came crashing down like a fat girl falling off a balcony...
When it turns off :P.
I dunno, when it starts sounding weird and weak.
Call me Wes.
Fender American Deluxe HSS Strat
Chicago Blues Box Roadhouse
Bad Cat Cougar 5
1957 Gibson GA-5
Ceriatone 18w TMB Combo
Hughes & Kettner Tube Factor
Various Ibanez TS9s
Weber MASS Attenuator
1) stick out tongue
2) insert battery
3) evaluate

That's how I've always done it. Works for me.