Need help here guys

Hi all

I am trying to design a very small ( for tests ) wind turbine. I thought i would try the automotive method to try things out, It will be twin 55watt alternators. Rigged to a 12volt system. The bateries would be as many as needed for tests, probably 50ah.

My question is this:
How many bateries could be charged from this system if for argument sake it ran at 60% as i understand that it would be rare to get full wattage at any given time.

Many thanks

Comments

  • mike95490mike95490 Solar Expert Posts: 9,511 ✭✭✭✭✭
    Re: Need help here guys

    110A of alternator @ 60% = 66Amps output, on an exceptional day. Call it in reality about 20 amps, if that. I'd get the cheapest deep cycle battery you can, from PepBoys, WallMart, Cotsco etc... and try it with that. Should be about a $80 expense.
    Don't hold your breath waiting for it to charge the battery though, auto alternators are pretty lame chargers, all things considered, till you get them spinning at 8,000 rpm.
    Consider the pulley on the crank, is about 3x the size of the alternator pulley, and engine is 3,000 rpm cruising.
    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 ,

  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: Need help here guys

    A 55 W alternator is pretty small... ~4 A... are you sure you don't mean 55 A?

    Assuming they are 55 A alternators, and you have two of them running at 60% output, the output would be 55 A x 2 x 60% = 66 A. That would be appropriate for a flooded-cell 12 V battery bank rated at between ~500 Ah (13% charge current) and ~1,300 Ah (5% charge current).

    If they're 55 W alternators, then divide the above results by ~14.

    You'll need to get the batteries to ~14.4 V and hold 'em there for a couple of hours in order to recharge the batteries. Assuming they're flooded cell batteries, you'll also need to equalize 'em at ~15.4 V every one-to-three months for proper maintenance.

    HTH,
    Jim / crewzer
  • mike95490mike95490 Solar Expert Posts: 9,511 ✭✭✭✭✭
    Re: Need help here guys

    you might check out some of the work here : http://www.otherpower.com/otherpowerfront.shtml with homemade wind genies

    http://www.otherpower.com/otherpower_wind.html
    http://www.otherpower.com/otherpower_wind_alternators.html
    excerpt: "Vehicle Alternators
    * Advantages: cheap, easy to find, pre-assembled.
    * Disadvantages: high rpms required, gears or pulleys needed, low power output, slip rings need maintenance.
    * Suitability for Wind Power: POOR

    There are some articles there for auto alternaters, since they are easy to get, and some info on how to MAKE a better suited one from a disc brake rotor.
    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 ,

  • System2System2 Posts: 6,290 admin
    Re: Need help here guys

    Well, thankyou guys, great help, made me sort of realise that the alternator method is too power lossy for this application, can you guys recommend a good all round motor for this, single or 3 phase.

    I do have a motor to hand with a decent shaft arangement but cant make out if it is 3 phase or single, its a Creda Limited psc motor type 328 / 220 -240v 50hz 1.2Amp class f. I know its only 1.2amp but if it is 3 phase then i can use this to test a wheatstone bridge i have made.

    Thankyou all very much

    Don
  • mike95490mike95490 Solar Expert Posts: 9,511 ✭✭✭✭✭
    Re: Need help here guys

    check some of the links at http://www.otherpower.com/otherpower_wind.html about servo motors, and induction motors.
    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 ,

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Need help here guys

    one thing i didn't see anybody mentioning about the automobile alternators is that they consume power from the field coils whether the main shaft is turning or not.
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