Solar office

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Comments

  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Solar office

    A battery needs higher than "full" voltage to "push" the energy into the battery. A fully charged battery will be ~12.6,, but it might want ~14.4 volts to get it to 12.7,,, something like 13.? to keep in in "float" If all you are charging is 12.7 volts,, the battery will never get full,, it may not even over come it's self discharge.

    All pretty simple,, and yet quite complicated.

    If you haven't yet read any of these,, they are pretty informativ.:
    http://www.windsun.com/Batteries/Battery_FAQ.htm#Lifespan%20of%20Batteries
    http://www.batterystuff.com/tutorial_battery.html
    http://www.batteryfaq.org/
    http://www.rpc.com.au/products/batteries/car-deepcycle/carfaq4.htm#charge

    More than enough to confuse anyone!

    Tony
  • dave g
    dave g Registered Users Posts: 17
    Re: Solar office
    icarus wrote: »
    More than enough to confuse anyone!

    Tony

    Yes it is - thanks :-)
  • dave g
    dave g Registered Users Posts: 17
    Re: Solar office

    Well all seems to be going well so far. I've had it running the TV & lights for the past few nights, no problems. Today it was overcast all day so I took the opportunity to screw a piece of plywood to the wall, mount all the equipment and clean up the wiring. I made some buss bars with screw terminals for the output (extras for future too), grounded the negative side of the battery (as recommended in the controller's manual), and put fuses in both the positive line from the panels and the positive line to the output buss.

    Incidentally, I was having a heck of a time finding fuse holders with screw terminals until I remembered that when I bought this house (way back when) I took out a lot of the old knob & tube wiring stuff and saved the components. Low and behold, I had a 1901 vintage, two socket, ceramic & brass, edison base fuse holder in perfect condition. I could only find 15 amp fuses locally, but I see that I can order lesser ones on line. Newer ceramic lamp holders would do just the same thing, but I like the 108 year old one :-)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Solar office

    Sounds like you are "Back to the Future" -- or is it "Forward to the Past". ;)

    Regarding the fusing... Normally, you would have a heavy cable from the battery to the positive bus bar (and be very careful that the battery to bus bar wiring is well made and won't easily short--and probably cover the positive bus bar so that nothing metal can fall on it and short). And put the fuses on each lead as it leaves the bus bar....

    This allows the battery to feed the bus bar just as if you where stacking connections directly on the battery post. And protect all of your down stream (and presumably lighter gauge) wiring to their respective loads (charge controller, inverter, DC loads, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • dave g
    dave g Registered Users Posts: 17
    Re: Solar office

    My 4th panel arrived today!
  • dave g
    dave g Registered Users Posts: 17
    Re: Solar office

    Four months on, all seems to be going well. I've been running the TV, converter box, and VCR exclusively off the system since early May. Had one power outage during the day where I switched my computer over to battery power for a couple hours, and that went just fine too. I guess the real test will be to see (over time) if I'm abusing the battery. One of these days I'm going to install a couple of light sockets wired 12 volt (for "emergency" use only) and use the two CFLs that came with the kit in them.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Solar office

    a summer of use is one thing, but the real test is in the winter around december and january when there's far less sun and snow cover on the pvs. this can deplete your battery(s) very easily if you don't watch your levels incoming and outgoing. some swear by the battery meters like the trimetric. even if you use that you will need a heightened awareness in order to keep your battery(s) from being depleted or damaged.