system draw

Hey guys, Just trying to work out how long it takes for my battery to go below starting voltage when my system is on but the engine is not. So, how do i work out my sound systems draw?

Watts out, times 1.3 (in the case of digital amps) or 1.5 (in the case of A/B amps), divided by 12.6. That formula will give you total current demand, but without knowing temperature, state of charge, ampacity, etc., of the battery, all you'll ever be able to do is guess how long, exactly, you'll be able to sit and listen. Also, the above formula only applies to WFO operation. If not running wide open, you'r current draw will be less, resulting in a longer listening time. If you know EXACTLY how many watts you are asking the system to make, at all times, then you can apply the above to your equation, but since music is dynamic, the current requirements will be as well.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Thanks haemphyst