IIRC, VA = RMS current x RMS voltage. VA=Watts when you have a constant
load like a lightbulb. Introduce things like switching power supplies
and it's not so constant.
I would just ignore the VA since you're interested in the current across
the battery. A watt's a watt, but you do also have inverter
inefficiency. Maybe 90% at best? Which I'm sure gets worse as the
battery voltage drops.
On 1/25/2018 9:49 AM, Adam Moffett wrote:
I wanted to rig up a load test for some batteries.
I don't have a substantial 12V DC load, so I set up a 1000W inverter,
a short extension cord, a Kill-a-Watt meter, and a heat gun.
With the heat gun on low, The kill-a-watt reads 110v, 606 VA, and 355W.
The question is how much load is this putting on the battery?
Somewhere between 30 and 60amp I guess, and either way my multimeter
can't measure more than 10A DC current, so I can't measure it directly.
My Googling on the topic has failed to enlighten me. My instinct is
to think that Watts is Watts, so I should probably use 355W in my
calculation of battery capacity, but I'm not sure.
