350 watt inverter doesn't carry load

[Hal Nash]

My electrical system at my cabin is a simple solar powered generator.  My panel charges 2 deep cycle batteries.  Then I run wire into the cabin into a 350 watt inverter, with a max of 800 watts.  However the inverter shuts off when I turn on 3 lights each with 60 watt bulb..only a total of 180 watts.  Whats really weird is that I can turn on two lights (120w) and run a tv/vcr combo that takes 65w and everything works great.  But shouldn't the inverter handle anything up to 350w total?
Thanks.

[glenn kangiser]

It should -and I have probably overloaded a few of them in my time.  Some of the 350 watt ones came with a cigarette lighter plug that is not sufficient to carry the 350 watt load.  Put bigger wires connected from the terminals directly to the battery.  Get rid of the incandescent bulbs and switch to compact fluorescents.  Same lumens using a fraction of the power.

Hope this helps.

[Amanda_931]

I don't know.

Which isn't going to stop me!  

Friend of mine had problems when he cheaped out buying a minimal panel, never got his batteries fully charged.

So that a PL13 fluorescent would barely run after the inverter.   In addition 13 watts was the bulb, not the rest of the lamp, it's own re-inverter, ballast, etc., all of which use up a bit of electricity.

Stereo systems have output rated in watts.  Any possibility that that is the setup with the TV-VCR?

Also is the TV on all the time even after you turn off the power button--i.e., the quick start provision giving you a phantom load?  If so how much?  

[rdpecken]

I would tend to agree wit Amanda on this. It sounds like the batteries might not be reaching a full charge.  My small 350 watt sine wave inverter shuts down and sounds an alarm when the battery voltage drops too low.  

Although voltage is not the best indicator of state of charge, you can make a rough estimate by looking at the voltage.  At full charge, a typical lead-acid 12 volt battery will be at 12.8 volts.  This would be with no load connected, and no charging being done.  It would be best to make this measurement after letting the battery bank sit idle for 24 hours.

At 50% discharge (which you should strive not to exceed), the voltage will be around 12.2 volts.  That's not a lot of difference in voltage, and there is some variation due to temperature changes.  But you might be able to make a guess as to your charge state based on that.

The best way to measure charge state is with a hydrometer.  You used to be able to get these in auto parts stores, but I don't know any more.  With them, you suck some of the battery fluid up into the dropper, and see how many balls remain floating (or what color of balls, depending on which particular hydrometer you select) or some of them have a floating gauge that looks like a thermometer.

If you find you are not reaching a full charge, you might improve things by increasing the size of the wires from the solar panel to the batteries.  Other than that, it is a matter of more panels, or less use.

Hope this helps... Randy P.