Battery/controller and very fast discharge? Help.

[agjackso]

Hello,

This is my first time posting on this board, and it seems like you folks are the best at answering questions about off the grid systems.

System:
I have a setup meant for an RV, and it includes the following items:
Solar Array: Go Power 120W portable solar panel (monocrystaline) (18V output, 6.6A max) -
--Controller: Landstar 12/24VDC 10Amp solar controller (comes built into the solar panel). The landstar controller has settings for different battery types, and it's currently set to "sealed" versus the gel or lead acid settings. I charge the panel in full sun, I'm located in Southern California.
--Battery: 60AH 12V VMAX-tanks AGM battery recommended voltage 7A, 14.7 max charging voltage. The 60AH AGM VMAX tanks battery had arrived in my possession at 14.3 volts, and then I proceeded to discharge it down to 10.5-11V before the inverter shut it off (I left it running while I left the house, not brilliant). I then recharged the battery to around 11.8-12.3V (max that the panel would allow it to go) and it stayed in this state for around a month (this may have been a bad idea, and feel free to criticize me). I had surgery on my arm, so the system remained stagnant for about a month while I couldn't do anything.
--Inverter: Xantrex 1000w inverter (with fuses in the appropriate locations). Cables = 0Gauge

-I called Go-power and they told me that the battery should be charging well beyond 12.3V mark, and replaced the solar panel. The new combo (solar panel and controller) brings the battery to 12.7 V (I have read that this is considered fully charged, which would be great, but it discharges back to 12.0V within an hour of use with a laptop).
--I've generally been using the inverter with the battery because the controller doesn't have a volt meter, and the inverter does have one. I also try to use the inverter to power a laptop while the battery is charging (this may or may not be a mistake, so please feel free to criticize me for my ignorance and idiocy if this is ruining the system).

The issue that I'm having is that the panel/Landstar controller won't bring the battery beyond 12.7 volts (this in itself wouldn't be an issue) and then at 12.7volts the battery discharges remarkably quickly down to around 12.0 v (within an hour of using a fan or powering a laptop). I had expected AT LEAST 5-10 hours of a laptop or a fan from this battery/inverter setup, but I'm grossly disappointed.

Based on my description, I think there are three possibilities based on my relatively poor knowledge of solar systems:
1) This is a problem with the Landstar controller not capable of returning the battery to 14.4 volts
2) I screwed up the battery by discharging it extremely low, and then not bringing it back to a fully charged state for over a month
3) or I'm doing something wrong by having the inverter powering a device and simultaneously charging the battery, which for some reason brings the charge down quicker than it would otherwise.

Would anyone care to validate my hypotheses? Or offer their own opinion? I realize I'm a novice and may have broken some aspect of my system, but I'll take the criticism and learn my lesson. I'd prefer to be informed and regretful, than ignorant and unaware.

Thank you.

Cheers,
Alex

[Sunking]

Real simple you are in deficit charging. Everything you have is undersized to do what you want. You are spending $100/day and making $50/day. You are insolvent and bankrupt like the state of CA.. During the charge cycle you should be seeing up around 14,5 to 15 volts at end of charge cycle and float at 13.8.

Easy solution get a battery isolator, 220 AH battery, and leave the solar stuff at home. Then all you have to do is start he RV engine and let it idle 30 minutes each day or drive 15 minutes to get some beer. Problem solved and another Happy Camper!

[SunEagle]

You mention the charge controller was set to "sealed". I would first check to make sure your AGM battery is a "sealed" and not a "gel" type.

It is possible that your 120 watt panel is not producing the maximum 6.6 amps during peak sunlight.

Even if it is, your panel is rated 120 watts and you are using a PWM charger which drops your panel to only 80 watts max.

Maybe you don't have enough panel wattage to properly charge your battery to full.

[inetdog]

I would first check to make sure your AGM battery is a "sealed" and not a "gel" type.

Good morning SunEagle. Have you had your coffee by now?
A sealed battery or VRLA battery can be either AGM or GEL. I have never seen an AGM battery that was GEL.
If you are talking about the "sealed" setting on the CC, that could either be for AGM or for GEL or a compromise setting. Need to look at the actual voltages it selects.

[SunEagle]

Good morning SunEagle. Have you had your coffee by now?
A sealed battery or VRLA battery can be either AGM or GEL. I have never seen an AGM battery that was GEL.
If you are talking about the "sealed" setting on the CC, that could either be for AGM or for GEL or a compromise setting. Need to look at the actual voltages it selects.

Actually I have had too many coffees. You are correct. My bad.

[Sunking]

Does not matter if it is AGM Gel, or FLA. It is lead acid period and 12.7 while on a charger is a dead battery.

[agjackso]

OK, so then what should I do? Would it be possible to find a solar controller that doesn't reduce the potential from 18V down to 12-13V and uses the batteries limit of 14.8V? When I check the output from the controller with a multimeter, it reads roughly 13V. It's not really an option to return any of the equipment, so I need to figure out how to make the system I currently have function optimally (if that means buying a solar controller, I wouldn't mind that, but it really needs to get that battery up to around 14V).

This type of advice would be greatly appreciated.

[inetdog]

OK, so then what should I do? Would it be possible to find a solar controller that doesn't reduce the potential from 18V down to 12-13V and uses the batteries limit of 14.8V? When I check the output from the controller with a multimeter, it reads roughly 13V. It's not really an option to return any of the equipment, so I need to figure out how to make the system I currently have function optimally (if that means buying a solar controller, I wouldn't mind that, but it really needs to get that battery up to around 14V).

This type of advice would be greatly appreciated.

Try charging your batteries with a standard AC driven charger, even if you have to disconnect one and take it somewhere else to do that. If the battery comes up to 14 volts the problem is that you are pulling more from the batteries each day than the panels can provide. There is no magic cure for that. You have to get more panels and an MPPT charge controller so you use all the power from them, and you have to reduce your loads.
If the batteries will not come up to 14 volts on a regular charger, then in addition to being undercharged they are destroyed and will need to be replaced.