Thanks to all replies. Seems I need more detail:
Items used:
Chicago Electric model 92464 (harbor Freight)
Auto Shut Down
Modified Sine wave
OK, there's your first problem (of several). "Modified Sine Wave" is a marketing euphemism for "glorified square wave"; it only vaguely resembles the TRUE Sine Wave power that is THE standard for AC power distribution throughout the world. Here is a graphic representation of the difference between these two waveforms:
El-cheapo inverters use "Modified Sine Wave" because it is cheap and easy to implement. But many devices designed to run on sine-wave AC power (particularly devices with motors and similar) do
NOT like it at all.
Inverters which produce true sine wave output
ARE available; but you aren't going to buy one for $129. Here is an example of a
QUALITY 2,000-watt 12V/120V inverter:
http://www.mastervolt.us/marine/products/mass-sine-12v/mass-sine-12-2000-120v-60hz/
But sit down before you check the price tag.
2000W/ 4000w surge capacity
Given the "parentage" of this unit, it would be prudent to "derate" that significantly. Cutting those numbers in half might be a good starting point.
Input 11-15VDC
overvoltage shut off @15VDC
As "theoldwizard1" pointed out, there is almost certainly an UNDERvoltage shut-off as well. But even if there isn't, feeding the inverter with inadequate voltage will surely produce inadequate (read: "unusable") output anyway; so it boils down to the same thing.
Note that this is obviously just the IDLING current (i.e., with ZERO load on the inverter).
AC and refrigerator were not tried at same time.
Even so, it's near-certain that either one is "too much" for your battery/inverter setup.
Portable AC: AC ran when connected directly to converter, but power seemed to be "struggling"
620W
120V
6 amp
60Hz
I'm not surprised that it was "struggling". First, because of the non-sinewave input, secondly because the input voltage was almost certainly inadequate, especially during the start-up cycle (when the unit can be expected to briefly draw several times its normal "running" current).
Refrigerator: Cool positions were in the Zero position when i tried to run it and Inverter tripped before i could turn it Refrig. on.
115V
8.5Amp
978 W (V x A)
60Hz
Again, this is surely because you were overloading the battery/inverter rig severely, especially during the start-up cycle.
Connection:
Batteries connected :
(pos to pos to pos and neg to neg to neg)
2003 Saturn SUV battery
Let me guess... Probably rated at somewhere between 50-75 Amp-Hours. As explained previously, that's nowhere near enough.
6ft 4 Gauge Battery cable with claws (multi strand copper wires)
Not even close to good enough. Even the rather "optimistic" recommendations in the manual for your inverter call for AWG 2 battery cables; and they should be absolutely as short as possible (yes, even six feet
IS significant in this context). And the additional series resistance imposed by the crappy contact between those "jumper cable" clamps and the battery posts only exacerbates the situation.
By way of comparison: If I were attempting to set up such a rig, I'd probably use 1/0 or 2/0 for the inter-battery connections (each of which would be measured in INCHES), and at least 4/0 (maybe doubled-up 4/0) for the main connections to the inverter.
Marine battery (no other details except it had two posts on each side)
Possibly a bit larger than your Saturn battery; but still surely inadequate (by a country mile, as the saying goes).
6ft 4 Gauge Battery cable with claws (multi strand)
And again, not even close to good enough.
Outdoor extension cord 30ft size 16/3
As alluded to earlier, this wasn't your biggest problem; but it wasn't helping, either. Earlier, you said "medium duty extension cord". FWIW, I would not call a 30-foot AWG 16 cord "medium duty". Depending on whose formula (or more specifically, whose resistivity constant) you care to use, as little as 12 amps through that cord would be enough to produce the maximum recommended (3%) voltage drop between the source and the load. And even that presumes full voltage at the source, which you near-certainly did NOT have.
why doesn't it work...seems to me it should......
what is the verdict?
See above.
Seems i need to give more detail.........
Oppps......am wondering if i posted a reply or not....i did something....sigh sigh.....
anyway, if i didn't post, here goes again...
sorry, not familiar with how to use these boards....mea culpa....
Your earlier post DID come though. So no need to address this repeated information.
I repeat: not going to work!!
A 620w air conditioner will pull approximately
62 amps from your battery when running with nothing else!
Actually, by the time you consider inverter losses and the fact that she's dragging down the batteries insanely fast, that "6 Amp" air conditioner is very probably pulling at least 70-75 Amps out of the batteries once it's up and running. The start-up current is surely in the HUNDREDS of amps.
Your saturn at idle might put out 40 useable amps. Your battery is less than 100 amp hours. Do you see the problem?
"Pearl" does seem to be a bit math-challenged.
Now you want to add more than an air conditioner? I REPEAT: NOT GOING TO WORK!!!
Agreed. As I posted earlier, it's going to take a MUCH larger battery bank (and very probably a much better-quality inverter).
IF: You add four large deep cycle batteries, and a 300 amp alternator to your Saturn, it might work, for a little while. Expect to spend over $1,000.
Four Group 8D batteries (at about 250 A-H each) MIGHT be enough to get this going, and keep it going for long enough to be marginally worthwhile. Four "normal"-sized automotive or marine batteries won't stand a chance.
[The BBS software is nattering at me that the message is too long. So I'm breaking it here. Continued in next message...]
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