Help!!!!

Without knowing your exact loads/usage... It does become a bit difficult to design/understand what a solar power system will be capable of when trying to match these unknown loads against what hardware you already have.

But, let's start with your battery. I call it the "heart" of your system and understand what it can provide--On average.

A 12 volt 200 AH (probably) AGM battery. Assuming you fully charge it at home (trickle charging is an in-exact term--Need to better understand what you are using to charge the battery). In round numbers, assume that you use 1/4 of the battery capacity for the two days you are at the cabin and 50% maximum discharge (for longer battery life).

• 200 AH * 0.50 capacity = 100 AH for "use" over those two days
• 100 AH / 2 days = 50 AH per day of "useful" energy
• 12 volts * 50 AH = 600 Watt*Hours of "useful" 12 VDC energy

You did not say if you have 12 VDC TV and DVD Player or a 120 VAC TV and Player... And the other loads (20 Watts here and there) -- Don't know what those are either (12 VDC or 120 VAC)--But guess those are LED lighting. Guess that you want ~5 hours of lighting per night.

• 20 Watts * 5 hours = 100 WH
• 600 WH of battery energy per day - 100 WH for lighting = 500 WH of available power for TV+Player
• 100 Watt TV + 40 Watt DVD player = 140 Watt load
• 500 WH of available power / 140 Watt load = ~3.6 hours of TV+DVD per night

The above is a very rough calculation--But does seem to be somewhat inline with what you could expect to get from your battery with your loads.

HOWEVER, I do not know if these are 12 VDC or 120 VAC loads... If 120 VAC loads, then you have an AC inverter which draws extra power (more losses) just "turned on". And depending on what exact brand/model of AC inverter you chosen, these losses can be relatively small, or can be fairly large (and do you turn off the AC inverter when you are done for the evening, or do you leave it on the 36 hours you are there?).

Next, you have a 100 Watt solar panel... So you can get "extra power" during the weekend from the panel if you have a proper charge controller. Again, taking some guesses. Somewhere around Phoenix AZ, fixed array:
http://solarelectricityhandbook.com/solar-irradiance.html

Phoenix
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 57° angle from vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
4.92	5.55	6.45	6.83	6.74	6.57
Jul	Aug	Sep	Oct	Nov	Dec
6.08	5.78	6.03	5.82	5.24	4.74

So, here we are in Mid-June, the average amount of sun per day is ~6.57 hours of sun:

• 100 Watt array * 0.52 average off grid system eff * 6.57 hours of sun per day (June) = 342 WH per day (June)

During the month of June, your 100 Watt solar array will "give you" and extra ~342 WH per day when it is sunny (over and above just discharging the battery bank by itself).

All of this is highly speculative--And we have not looked at the rest of your hardware (AC charge controller for during the week charging, solar charge controller for weekend, AC inverter or not, other loads like cell phone charging, running a radio/internet music/etc., etc.).

And simple issues like the AWG (diameter) and length of copper wire connecting your battery+inverter+loads together... Are you bolting up the electrical connections or using alligator clips (alligator clips do not make good/reliable connections for AC inverter power)...

The AGM battery you have--Generally these types are intended for UPS systems (sit in standby for months or longer at a time, then on for 30-60 minutes--And get replaced every ~2 years). They are a particularly sensitive to being overcharged -- Having a good Digital Voltmeter to double check charging/resting/discharging voltages will help you better understand how the battery is doing in your installation.

Do you have any other meters? Kill-a-Watt meter (to measure AC power/Watt*Hour)? A DMM (digital multimeter)? Other test gear (current clamp meter, DC AH/WH meter, etc.)?

Other issues--Generally, solar/battery power is relatively "expensive" and conservation would be a big help. Newer LED TVs generally use less than 100 Watts of power, DVD players should use less than 100 Watts (I have not measured any of my TV+DVD players with a Kill-a-Watt meter in years--But would be a good place to start).

Using a laptop+CD/DVD player may be closer to 30 Watts or less--And use HDMI from the laptop to a TV if you need a larger screen... etc...

Anyway, some basic information to start with.

-Bill