I've recently purchased a 1500 watt inverter that seems to be having some issues that I can't explain. I don't want to send it back for an exchange if something else is the issue.
First the model is Cobra CPI 1575.

When I first turn it on, the two fans in the back whir up then it beeps flashing "OLP" (overload protection), then it does what it's supposed to do; flash the battery voltage then the watt output.

Next I grab my volt meter and check the AC output voltage through the plugs in the front and it reads 98.0 Volts. It's not even close to 120 Volts.

Could that be I need heavier gauge wire from the battery to the inverter?
Could it be I'm only running one battery?

One other thing is when I plug lower power items into it, the output shows zero watts, but plugging in an old fan, it shows the watt usage?

I am quite confused at why it's doing what it's doing.. Any advice would be appreciated. (before I pay to ship it back for an exchange)

 

What is the battery voltage it is showing?

 

13.4 Volts. It's on float charge

 

It's designed to be on a running car or truck battery while the engine is running, at 1500W that's about 120A from a 12V source your car battery will boil. You need very short and very heavy gauge wire to boot.

 

4 gauge at about 2 foot long is what I was thinking.

So I should check it on my truck before I send it back?

 

This while it is providing power? The other question I have is whether it is a sine wave inverter. I'm going to see if it has some online specs. If I find them I'll post the link on this post.

The manual...

http://cobra.com/Manuals/CPI1575_MANL.pdf

Not very good reviews overall. I suspect this product is flawed.

http://omgili.com/reviews/455C116B7...Watt-12-Volt-DC-to-120-Volt-AC-Power-Inverter

 

13.4 is with no load. It leveled off at 12.1 Volts with load, but the low volt output of the inverter made the fan buzz a bit.

 

What kind of load are you presenting it? If totally inductive that could be part of the problem.

 

It's an old desktop fan from the 60's. Smaller loads such as charging a cell phone show no watt usage at all.

 

Totally inductive and probably rather inefficient load.

Have you tried putting a few light bulbs on it?

 

no, but I will try that.

 

Well, let's see what it does. If you've got good wiring and a good battery it should be able to run a couple of 250W heat lamps.

 

I just tried a 75 watt black light bulb and got a current overload protection error and a low voltage protection error. Bulb was warm to the touch. The battery at 12.6 volts at the start of the experiment. During the experiment the voltage dropped down to 11 volts and the black light blinked every 5 seconds or so. Changed the bulb to a compact fluorescent bulb gave me no error, bulb lit up and inverter watt display read 000 watts...???
It's got to be my battery/cable thickness...

 

This while it is providing power? The other question I have is whether it is a sine wave inverter. I'm going to see if it has some online specs. If I find them I'll post the link on this post.

The manual...

http://cobra.com/Manuals/CPI1575_MANL.pdf

Not very good reviews overall. I suspect this product is flawed.

http://omgili.com/reviews/455C116B7...Watt-12-Volt-DC-to-120-Volt-AC-Power-Inverter

Thanks Bill.

 

Yea, I think you got a bad one or it was poorly designed to begin with.

Believe it or not Harbor Freight has some decent inverters as does NewEgg.

 

Great.

Thank you for the help.