It really all depends on your alt power...with only 2 banks,a g31 Northstar batt and 600amps of alt power on a TFE at .5 dropped only to the mid 13s after a song or 2....now lithium and caps?? Is beast! 5 banks a jb 40ah and the same 600 amps of alt power on 2 scv6000 at .5 i goes no lower than 14.5 3-4 songs straight clamping 6k+ each amp on the termlab magnum