Inverter INPUT Requirements

[ZDaniel]

If I have a 110 V 5000 Watt Inverter with 10000 Watt surge, My question is, At 12 V input, how many DC amps would be required to maintain that 110 AC 5000 Watt Inverter output assuming it were constant at 5000 Watts?

I am trying to calculate and choose the proper batteries and amps for this purpose and do not know how to calculate it. I will be using Trojan 6 volt or maybe 12 volt deep cycle batteries.

Thanks
Daniel

 

[iwire]

I would ball park it around 460 amps.

5000 watts / 12 VDC = 416 amps, if you are lucky maybe 90% efficient.

416/.9= 462 amps.

Of course I am just a hack, one of the engineers may prove me wrong.

 

[ron]

(5000W/12V) divided by the efficiency of the inverter.

 

[ron]

Bob, your right on.
I would have guessed the efficiency of the inverter being lower though.

 

[iwire]

Thanks, I took a stab at 90% based on my experience with PV inverters but I think there could be a large range depending on how much the OP spent for the inverter.

 

[LarryFine]

You can approximate inverters like transformers. With a 1:10 voltage ratio, you'd have a 10:1 current ratio.

For each amp at 120v, figure 10 amps at 12v.

I would have guessed the efficiency of the inverter being lower though.

Actually, many are higher, especially near full load.

 

[ron]

After looking at some inverters online, there is quite a range of efficiencies. 90% surely is out there, so go with Bob's calc.