Need help with my solar system...

[cclarkego]

Help me! I cannot figure out why my new batteries don't seem to be charging all the way up or holding much of a charge with little useage.

It has been a challenge for me as a woman, that never gave a thought to electricity before, except for flicking on a switch for light, to learn to understand the intricacies of my solar panel system now that I own a 1965 Airstream with an elaborate set up that a previous owner had installed for him. I have read the manuals that were left to me, but several important ones were missing. I figured out how to get it working and it ran perfectly for a year out where I boondock it on a ranch, until the eight year old gel batteries started failing. There is no shore power out there and I depend on the solar to run only my lights and occasional use of the Fantastic Fan.

I replaced the two old batteries with slightly larger new AGMs and a friend hooked it all back up. I reset my inverter/charger via the remote panel to the inverter/charger as directed. The problem is that the voltmeter is showing the solar is charging the batteries only up to 12.6 in the afternoon, then starts dropping slowly to about 12.2 by evening with no load on it. If I turn on the lights for awhile, it goes down to 12. Then a warning light comes on. I have even tried hooking up to my car with it running which gives it a small boost back up for a bit. Then I climbed up on the trailer roof, cleaned the panels, cut back some overhanging tree branches and the next day it made it to 13.1, but dropped right back down to 12.3 by nightime.

Here is what I have:

1) Two new Lifeline AGM 80 amp hour batteries

Everything below was installed in 2000
2) Heart Interface Freedom 458 (10) 1000 watt Inverter/Charger with basis remote panel (not Link 1000 or 2000)
3) 1 Siemens solar panel mounted flat on roof (which I think is a 75 watt from looking at pictures on the internet and measuring it to compare) (no manual or paperwork at all on this)
4) Specialty Concepts Mark 20 Photo Voltaic Charge Controller (with no manual or paperwork for this either and I have not tried fiddling with this at all)

I get sunlight to the panel from about 11AM to 6 or 7PM due to tree cover in the mornings. I am trying to get help to cut it back for more sun exposure time.

Any help will be greatly appreciated as I fear I am ruining my new batteries!

Carol