200 AA Batteries to make a portable power supply

[LionHearted]

Got some music equipment I wanna busk with but theres no battery slot... So I was just curious, can't I just get 200 1.2v batteries then get a wall socket to plug it in?

Might be a bit simple minded but I'm curious.

 

[davenn]

hi
welcome

wall power outlets are AC
Batteries are DC

see the difference

Dave

 

[BobK]

Yes, but only if play only songs by AC/DC.

What you need is a 12V battery (like a car battery) and an inverter.

Bob

 

[davenn]

Yes, but only if play only songs by AC/DC.

haha

 

[LionHearted]

Of course, My bad ><

Thanks guys.

 

[LionHearted]

Probably another bad question, is there a formula I can use to determine how long the batteries will last if I know the wattage, voltage and amps that are going to be drawn?

 

[davenn]

for rechargeable batteries, that's reasonably straightforward as they have their amphour rating on them

so say its a 2000mAHr battery that means at best you can draw 2 amps for 1 hour
in practice/reality it will be a bit less than that because of battery voltage drop and other factors

 

[BobK]

Look into deep cycle sealed lead acid batteries. These will have an amp hour rating. Since they are 12V, you multiply by 12 to get a Watt Hour rating. For example, a 35AH battery is 420 Watt Hours. If you music system uses 50W this would last about 8 hours ideally. But an inverter is going to be no more than 90% efficient, so maybe 7 hours. And furthermore, the ratings of this type of battery are for discharge over 20 hours. Faster discharge rates will reduce the available energy, so maybe 4 hours. If the music system required 100W it would be more like 2 hours.

Bob