Another power on location thread

I was in the process of creating my own power on location and half way throuh my project came across this thread. https://photography-on-the.net …hread.php?t=285​982&page=2

I have a bit of a problem and hope that someone with a bit of electric knowhow can tell me where I am going wrong. I'm not doing this completely by myself.

here my setup

I got a power tester and after plugging and firing my lamps got the following figures to see what was being drawn

AMPS
Idle Peak
0.61 1.11

Watts at half power
Idle Peak
96 145

Watts at full power
idle Peak
148 239

So I got myself a 300w invertor. the invertor also comes with a cigar lighter adapter. The first test that I carries out was connect the invertor via the cigar adapter and then plug in the light. The light functioned great at half power. At full power it was fine on idle, but as soon as I flashed it, the invertor started to beep a constant tone. This was fine, as the book did say that when using the cigar lighter, the power must not exceed 150. Which is why is was ok on half power and on ide at full power (being below 150w)

Then I connected the invertor using the croc clips (which came supplied) to the battery terminals of the car. Half power no problems and even at full power no prolems at all. Yes it works.

OK this is where the problem is. I received a 12v 18amp sealed battery yesterday and connected everything together. When I plugged in my light to the invertor I received a constant beep (referring to the book - power overload). The light had not even been switched on, all I did was plug it in. No matter what I plug into the invertor, it just beeps a long beep.

Any ideas on what this could be?

I was going to disconnect the invertor from this battery and try from the car's battery again as I originally did when carrying out my tests, but didn't get the time.

Help

Am I using the wrong current battery.?

no one ?

I am not familiar with the 18 amp battery, but I know something about testing the car batteries.

A typical car battery is rated about 600 cold cranking amps, we test it by add a load to battery to emulate a current draw for about half the CCA, so about cranking 300 amps. If the car battery could hold the voltage above 10v for 15 seconds, it pass the test.

I will let someone else to do math about amps and watts, but I suspect the 18 amp battery: 1) need to be charged up first, 2)or does not have enough capacity, so when a a load is added (inverter), it's voltage drops to the point that set off the beeping alarm.

Lotto wrote in post #2876347
I will let someone else to do math about amps and watts

Well I ain't no Tom Edison but from what recall, volts x amps = watts. 12 x 18 = 216 watts. The conversion to AC won't be 100% efficient, so 216 watts in will give you less than 216 watts out.

The OP seems to have the testing equipment to figure out the voltage under load. Probably something he should test.