What is wrong with my system?

The first question is, how long are you running the light and TV ?
You said until midnight, but you didn’t say when you are turning them on.

My initial guess is that you are drawing the battery down too far and experiencing a low voltage shut off sometime during the night.

If you are leaving the draw switch on, the inverter puts about .6 amps load (about 7 watts) on the battery. Turning that switch off will reduce the load to less than 2 milliamps.

Disconnecting the inverter could allow the voltage to recover to above the low voltage disconnect limit, and would reset the inverter.

What type of solar charge controller are you using ?

You may also be estimating your load a little on the low side.  What make/model of TV do you have and how many watts is that light ?

hello,

I think I saw the photos that were just posted on the forum.
beyond the functionality of the system, I have some serious safety concerns that i think should be addressed.

1.  the terminal blocks on the wood under the modules are not acceptable.  pv is live in sunlight and although there is a wood block in between, that wiring is not safe for outdoors.  I would strongly recommend a combiner box for putting modules in parallel.  each series string should have its own series circuit breaker or fuse.  if you have all 8 in parallel then you would likely have 8 15a din rail circuit breakers mounted in a box something like this. 

http://store.altenergystore.com/Enclosures-Electrical-and-Safety/Electrical-Enclosures/Combiner-Boxes/Outback-FLEXware-PV8-Combiner-Box/p6693/

this box would typically be mounted outside right by the modules. all pv wires would go in, negatives tie on the bussbar and positives each go through a breaker. then you would leave with 1 positive (ideally red) 1 negative (ideally white) and one equipment grounding conductor (ideally green) from that enclosure.  you would roughly likely have 64a at 12vdc so at least 6awg would be required.  you should be able to source that in colors locally at home depot.

2.  regarding the power center setup.  i see a square d disconnect but i cant make out the unit.  being that you have more than 60a rated dc power at 12v, i think that it is incapable of breaking that cirucit.  from the tristar i dont see wires going to the battery bank.  the tristar battery output must go to the battery terminals or busbars pulled from the battery terminals.  the output of the charge controller must not be connected directly to the inverter.

3.  battery to inverter cables should be connected to the battery terminals with appropriate lugs.  the alligator clips should not be used in permanent installations as if they are bumped they have the ability to create dangerous sparks and arcs.  if a common busbar is needed to tie the battery to the inverter, an enclosure like this is generally used.  this will enable you to use battery cables with 3/8 lugs (if the inverter can accept them) that will make safer connections and allow for an appropriate disconnect.

4.  the battery and cables from it especailly are too small for the inverter.  for a 2500 w inverter at 12v size 4/0 would be appropriate.  find a deep cycle battery with threaded posts on it or even two golf cart batteries from wal-mart and use 4/0 cables with to connect batteries to each other and batteries to inverter (or dc disconnect center).

http://store.altenergystore.com/Enclosures-Electrical-and-Safety/Electrical-Enclosures/DisconnectLoad-Enclosures/Dc/Midnite-Solar-MNDC250-Mini-250-Amp-DC-Disconnect/p2416/

or

http://store.altenergystore.com/Enclosures-Electrical-and-Safety/Electrical-Enclosures/DisconnectLoad-Enclosures/Dc/Outback-FlexWare-FW500-DC-breaker-enclosure/p5576/

before addressing functionality, i am very worried for safety and fire hazards.  good luck in the process, and please feel free to ask more questions, the forum folks would be glad to help.

james
altE staff

I 've three 12v 33AH batteries in parallel right now, TV and light use battery power only after 5:30pm until 12:00am.

 hi gary,

 good advice on beefing up on that wiring and battery bank. me thinks that's gonna help alot.

"simple and cheap as well."

 i agree that this can be "simple" but cheap? i guess that is relative. someone without company connections might expect to pay about five grand for a 1kw array of pv. for me that ain't cheap. i was thinking prices might start to come down a little by now. where are the $1/watt modules we all were promised? maybe next year..

cheers and good luck, dave

 Gary;Here is some good reading

"Photovoltaic power systems and the 2005 National electrical code suggested practices"

 Tried to create a link for you but I cannot. A search should find it ok.It is in PDF format.
The AltE site has some cabin package systems that have a wiring diagram also.A wire size chart is suggested too.

 It does look dangerous.You really do not want to leave terminals where anybody can get to them (or animals)Those + - rails exposed no good.As mentioned a combiner box is missing,then you should go to a DC disconnect box with a ground fault.Grounding procedures should be looked at too.

 Good thing you asked these guy`s, best of luck to you.

Thanks Robert.