Power Calculations

I know that the stuff I have is more than enough for my mobile DIY External power source,

I have an 108AH Deep Cycle Marine Battery and a 600W pure sine wave inverter and a 450W regular inverter.

I'm doing some calculations, based on the Eqn; Watt = Amp * Volt

The AB800's are 6A, 105-125VAC that would be about 600watt or so right?

What's the point of the calculations?

One thing you have not figured on is the inefficiency of inverters. You will lose up to about 20% of the power being delivered from the battery due to efficiency loss.

Another thing is that you should never draw a deep cycle battery down much below 50% of its capacity if you want it to last very long, especially if the battery is a combination deep cycle and "starting" battery which most marine batteries are. Thus, divide the Amp-Hour rating by about two for a more realistic in-the-field capacity.

I was just wondering... the AB Vagabonds are like 20plus AH and they can last pretty long,

the one i picked up is over 5 times the AH rating, so I think it shd be more than enough.

These are the dedicated deep cycle, the yatch that I pulled the batteries from had 2 dedicated 24V starter batteries and 6 of these 12V deep cycle for running when off shore.

I figured if I wanted a decked out, outdoor shoot, that 1 battery should be enough, for 2 AB800's, 1 laptop and some modeling stuff, ie, fans or lights or hair curlers...

SkipD wrote in post #5761383
What's the point of the calculations?

One thing you have not figured on is the inefficiency of inverters. You will lose up to about 20% of the power being delivered from the battery due to efficiency loss.

Another thing is that you should never draw a deep cycle battery down much below 50% of its capacity if you want it to last very long, especially if the battery is a combination deep cycle and "starting" battery which most marine batteries are. Thus, divide the Amp-Hour rating by about two for a more realistic in-the-field capacity.

Aaagogo wrote in post #5761336
The AB800's are 6A, 105-125VAC that would be about 600watt or so right?

About right. But they only draw that much current when they're recycling. When the strobes are fully charged they draw almost nothing unless you're using the modeling lights.

I'm not sure what your question is. Are you trying to determine if the inverter is powerful enough to cycle the strobes, or are you trying to determine the number of flashes you'll get out of the battery?

Aaagogo wrote in post #5761631
I was just wondering... the AB Vagabonds are like 20plus AH and they can last pretty long,

the one i picked up is over 5 times the AH rating, so I think it shd be more than enough.

These are the dedicated deep cycle, the yatch that I pulled the batteries from had 2 dedicated 24V starter batteries and 6 of these 12V deep cycle for running when off shore.

I figured if I wanted a decked out, outdoor shoot, that 1 battery should be enough, for 2 AB800's, 1 laptop and some modeling stuff, ie, fans or lights or hair curlers...

I wouldn't even dream of using hair curlers or any other heat-generating device (a coffee pot, for example) on a battery. They will suck the energy out of a battery faster than you can imagine. For that sort of load, I would suggest getting a small generator.

In fact, a 2KW Honda EU series generator (extremely quiet) would probably handle all of the stuff you want to use for a lot longer than a battery's charge would last. It would also give you some emergency capability if your home's electric utility went out.

well, both I guess,

figure if and when I do another outdoor session, it should run about 2-3 hrs, with all hands on deck, MUA with her stuff, me and my laptop, strobes and possibly a fan or 2 here and there,

the 600W pure sin wave, and 450W regular inverter on that 108AH battery should last me just fine.

figure about 150-200 shots fired during that 2-3 hr session.

Curtis N wrote in post #5761780
About right. But they only draw that much current when they're recycling. When the strobes are fully charged they draw almost nothing unless you're using the modeling lights.

I'm not sure what your question is. Are you trying to determine if the inverter is powerful enough to cycle the strobes, or are you trying to determine the number of flashes you'll get out of the battery?

but buying a generator would mean I would have to spend more money,

i got almost all my parts for free, well, other than the pure sin wave inverter, which was also at an extremely low price. that's why I'm wondering if it's good, else I'm going to exchange the 600W pure sin wave for a higher Wattage inverter.

I didn't expect hair dryers, hair curlers suck up that much power.

I hope you read and carefully understood what Paul Buff was telling you on his forum. By using the wrong inverter technology, you could damage your flash units.