Vent Switch

54d1854d18 Solar Expert Posts: 73 ✭✭✭
What do most people use to activate the
vent on the battery box of a solar system,
and where do you get one?

Is there a homemade setup that would work?

Comments

  • AntronXAntronX Solar Expert Posts: 462 ✭✭
    Re: Vent Switch

    What charge controller you got?
  • mike95490mike95490 Solar Expert Posts: 8,463 ✭✭✭✭✭
    Re: Vent Switch
    54d18 wrote: »
    What do most people use to activate the
    vent on the battery box of a solar system,
    and where do you get one?

    Is there a homemade setup that would work?


    http://www.zephyrvent.com/ I've only heard good things about them. Or use AGM batteries .
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 29,697 admin
    Re: Vent Switch

    Add a note that AGM batteries when they age out/fail (overcharging, catalyst erodes) can vent hydrogen/electrolyte. So do be careful where they are mounted too.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • 54d1854d18 Solar Expert Posts: 73 ✭✭✭
    Re: Vent Switch

    I have a Rogue MPPT 30A Controller
  • AntronXAntronX Solar Expert Posts: 462 ✭✭
    Re: Vent Switch

    You could just install small 12V DC computer fan, and leave it running. Or you could buy one with speed regulator built in, set it to slow speed and leave it on 24/7. If you still want voltage activated fan, the circuit for voltage controlled switch is very simple. What voltage your system is, and what kind of battery?
  • n3qikn3qik Solar Expert Posts: 741 ✭✭
    Re: Vent Switch

    What is your PV voltage?
    Could use that to drive a fan/relay.
  • 54d1854d18 Solar Expert Posts: 73 ✭✭✭
    Re: Vent Switch

    My Batteries are configured 12v,
    and my solar array is 24v.

    I would rather not have it run 24/7
    I had figured having it come on at maybe 14v
    and go off at 13.5 or something like that.
  • AntronXAntronX Solar Expert Posts: 462 ✭✭
    Re: Vent Switch

    I could make you a switch like that. This is right at my level of expertise at the moment. How many amps your fan draws?
  • 54d1854d18 Solar Expert Posts: 73 ✭✭✭
    Re: Vent Switch

    I don't have a fan yet, probably less than 0.5a,
    like a computer fan, more like 0.2a or so I think.
  • n3qikn3qik Solar Expert Posts: 741 ✭✭
  • icarusicarus Solar Expert Posts: 5,345 ✭✭✭✭
    Re: Vent Switch

    I use a voltage controlled switch much like the one that Ken linked. I just had my electronics guru friend make one up. It turns on at gassing voltage, with a certain spread (hysteresis) between on and off voltage to keep it from cycling too much. Pretty simple, this then controls a Zepher fan and it works great.

    Tony
  • 54d1854d18 Solar Expert Posts: 73 ✭✭✭
    Re: Vent Switch

    I have a 12v computer processor fan, connected
    it to a mini solar panel, runs it perfectly, actually
    a little fast for my liking, 13.5 v while fan is running.
    With a little fitting, the fan fits perfectly inside of
    a coupling for central vac piping, the rest is easy.


    I may add a zener diode across the fan to hold the
    voltage down and keep the fan slowed down.

    Thanks for all the ideas...
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Vent Switch

    a zener needs a resistor to hold back the current as it would blow out the zener otherwise when it is handling too much power and this won't do much of anything for the fan itself anyway. try getting some standard diodes like 4001 or anything similar and put 2 or 3 in series with one of the leads to the fan observing polarity as reversing it (backwards) will stop any flow of power. the voltage drop of roughly a half of a volt per diode will cause the speed to slow down by the amount of voltage you have dropped. also accidentally shorting the power through a diode will pop it like a fuse so be careful.
  • icarusicarus Solar Expert Posts: 5,345 ✭✭✭✭
    Re: Vent Switch

    Find a 24 vdc fan. I get a collection of them from the local computer scrapper, cost me $1/lbs. I keep a selection of 12vdc and 24 vdc fans around for things like fridge fans etc.

    Tony
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