Gudcraft WG400 set up questions

islandguy
islandguy Solar Expert Posts: 80 ✭✭✭✭
At the moment my plan is to roof mount this generator. The metal pole will be about 7’ above the ridge. I realize this is not the recommended way to go about this but for an initial install, experiment, this is going to be the location. One of the issues faced at this location is some strict permitting and zoning issues involving wind generators. So the ability to tower mount a larger wind generator high enough above the tree line to work optimally, isn't going to happen.

The documentation and charge controller that came with the windmill were pretty basic so I do have some questions.

The pole will be bolted to a 2x12 bolted to the ridge. So the wires from the windmill will go to a junction box at this location. From the junction box I intend to run 10/3 about 30’ to the charge controller. At this ridge mounted junction box, what is the recommended lightning/surge suppression hardware that should be installed?

The charge controller appears to be very basic. Input from the windmill, output to the batteries and load. I’m guessing the load circuit is to prevent the windmill from overcharging the batteries. What is the recommended connection for the load circuit? Dump it to a ground rod? Load resistor? Another battery bank?

At this location there are generators powering battery chargers. Do I need to manually ‘brake’ the windmill before powering up the battery chargers? In other words will the gudcraft charge controller sense the increased voltage and send power to the load circuit? Or will the output form the charge controller confuse the Powermax battery chargers?

Since I ultimately plan to run two or three windmills at this site, is there a better charge controller that would be worth getting now? Also over the next few months I would like to add a 100 watt solar panel into the experiment. So planning ahead for a mix of wind. Solar and generators would probably be productive as far as wiring and charge controllers.

Also has anyone had any experience with the, ”Magnum Energy ME-SBC Two Bank Smart Battery Combiner 12/24VD” or something similar?

This location uses around 4Kwh per day all year round. At a rough guess $5.00 is being spent per Kwh between the cost of batteries, generators and fuel. So investing into wind and solar power will be well worth it. Now I am just working through the right mix of hardware and site limitations.

I appreciate the input. Thanks.

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions
    islandguy wrote: »
    At the moment my plan is to roof mount this generator. The metal pole will be about 7’ above the ridge. I realize this is not the recommended way to go about this but for an initial install, experiment, this is going to be the location. One of the issues faced at this location is some strict permitting and zoning issues involving wind generators. So the ability to tower mount a larger wind generator high enough above the tree line to work optimally, isn't going to happen.

    This is pretty tough... Unless you are able to mount this in an area with good, non-turbulent air flow--Expecting a "useful" amount of power from the turbine may leave you disappointed. Sort of like mounting a solar array in a forest...
    The documentation and charge controller that came with the windmill were pretty basic so I do have some questions.

    The pole will be bolted to a 2x12 bolted to the ridge. So the wires from the windmill will go to a junction box at this location. From the junction box I intend to run 10/3 about 30’ to the charge controller. At this ridge mounted junction box, what is the recommended lightning/surge suppression hardware that should be installed?

    Will the 30' of cable be in the air or buried? If buried, I would suggest the surge suppressor near the point where the wire goes under ground (and ground rod driven next to wire/foundation--you could always install another suppressor at the power shed too). If the wire goes through the air--I would suggest surge suppressor at the power shed.
    The charge controller appears to be very basic. Input from the windmill, output to the batteries and load. I’m guessing the load circuit is to prevent the windmill from overcharging the batteries. What is the recommended connection for the load circuit? Dump it to a ground rod? Load resistor? Another battery bank?

    You have to figure out what the "LOAD" terminals do... They may turn off the load when the battery voltage drops below 10.5 volts (protect battery/loads from brownouts). Or they may turn on when the battery voltage is >14.5 volts (dump excess charging energy).

    If this is a Dump Load control, then you would normally power some sort of resistive heater (hot air, hot water, resistor bank, etc.). If it had enough "smarts" you could program it to turn on at 14.5 volts and turn off at 13.0 volts--And use the output for water pumping to cistern (for example).

    Do not ever plan on dumping power to a ground rod. They typically have pretty high resistance (25 ohms maximum typical spec., so not too much current flow) and you would need two ground rods to make a circuit (hot and return to "heat" the earth). And, you could cause corrosion in any water pipes, re-bar in foundation, and even electrocute cattle, dogs, and other four legged creatures (and possibly humans too).
    At this location there are generators powering battery chargers. Do I need to manually ‘brake’ the windmill before powering up the battery chargers? In other words will the gudcraft charge controller sense the increased voltage and send power to the load circuit? Or will the output form the charge controller confuse the Powermax battery chargers?

    More or less, the charge controller with the highest voltage "wins". Except for dump controllers, where the dump controller with the lowest charging set-point "wins".

    What you don't want is the generator powering an AC battery charger trying for 14.8 volts, and the dump controller trying to keep the battery bank at 14.2 volts. If the is an automatic generator controller, the generator may stay running trying to power the dump load. Waste of fuel, but should be no damage.

    You would brake/secure the wind turbine if you knew that the dump controller was not working and/or there were very high storm winds forecast. Wind turbines that don't have a load (or where the blade torque exceeds the alternator torque) will over-speed and self destruct in moderate to heavy winds. But if your your turbines are down low in turbulent airflow--May not be a big issue.
    Since I ultimately plan to run two or three windmills at this site, is there a better charge controller that would be worth getting now? Also over the next few months I would like to add a 100 watt solar panel into the experiment. So planning ahead for a mix of wind. Solar and generators would probably be productive as far as wiring and charge controllers.

    I would suggest that you get one or several AH logging type meters so you can keep track of how much energy each source is providing to your system... The Doc Wattson may be good for your needs (if the current is less than ~20 amps and less than 60 volts). This only track power in one direction (not a true battery monitor which tracks current into and out of the battery), but you can see how much energy each charging source provides. Most middle to high end solar charge controller have logging. Few wind systems seem to be setup for logging (wonder why :confused:). Just because you see the turbine spinning does not mean it is generating much power.
    Also has anyone had any experience with the, ”Magnum Energy ME-SBC Two Bank Smart Battery Combiner 12/24VD” or something similar?

    What is it you are trying to do? Have two 12 volt battery banks, charge one bank and split some energy off to charge a second bank (typical use would be for an RV--Vehicle Battery and House Battery banks). This allows you to drain one bank (house) and still start the vehicle from the second battery.

    Otherwise, if this is a fixed installation--I usually like to recommend one battery bank--Multiple banks are a pain (balancing energy use, more maintenance, etc.).

    There are several ways to connect a 24 volt and 12 volt battery bank together with DC to DC charge controllers, or even bi-directional power converters (you can charge both batteries from 12 volt and/or 24 volt sources--Sometimes used on large motor homes/bus conversions that use 24 volts for vehicle power and 12 volts for house power).
    This location uses around 4Kwh per day all year round. At a rough guess $5.00 is being spent per Kwh between the cost of batteries, generators and fuel. So investing into wind and solar power will be well worth it. Now I am just working through the right mix of hardware and site limitations.

    I would also review the generator sizing/fuel usage vs loads... You can get ~3-5 kWH per gallon of fuel in a reasonable small AC genset+load combination (like a Honda eu2000i 1,600 watt inverter/generator). And you can get >5 kWH per gallon with a bit larger diesel gensets.

    A good way to better match the generator to loads is to use a small battery bank+inverter for night time loads, and use the generator for morning/evening loads + battery charging (hybrid use).

    $5 per kWH for generator + fuel + Battery Bank wear sounds a bit on the high side (being on an island will add shipping costs / middle of nowhere fees)--I presume).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions
    BB. wrote: »
    Will the 30' of cable be in the air or buried? If buried, I would suggest the surge suppressor near the point where the wire goes under ground (and ground rod driven next to wire/foundation--you could always install another suppressor at the power shed too). If the wire goes through the air--I would suggest surge suppressor at the power shed. -Bill

    The cable will run from the ridge, inside, out the gable end. Run about 20' along the outside of the house and in to the basement where the battery banks and chargers are.
    Initially I was thinking of a suppressor at the ridge location.

    I'll find out about the load circuit from gudcraft. The instructions had a manual switch for the windmill break. I can probably automate that with a relay once I understand the parameters better.
    BB. wrote: »
    What is it you are trying to do? Have two 12 volt battery banks, charge one bank and split some energy off to charge a second bank (typical use would be for an RV--Vehicle Battery and House Battery banks). This allows you to drain one bank (house) and still start the vehicle from the second battery.

    Otherwise, if this is a fixed installation--I usually like to recommend one battery bank--Multiple banks are a pain (balancing energy use, more maintenance, etc.). -Bill

    This is the location with Deep cycle batteries for the house bank and Auto batteries for the Well pump. So definitely a need for two different battery banks because of two different loads.

    If the windmill experiment works out I plan on adding another one for the well bank.
    BB. wrote: »
    I would also review the generator sizing/fuel usage vs loads... You can get ~1 kWH [should be ~3-5 kWH -BB] per gallon of fuel in a reasonable small AC genset+load combination (like a Honda eu2000i 1,600 watt inverter/generator). And you can get >5 kWH per gallon with a bit larger diesel gensets.

    A good way to better match the generator to loads is to use a small battery bank+inverter for night time loads, and use the generator for morning/evening loads + battery charging (hybrid use).

    $5 per kWH for generator + fuel + Battery Bank wear sounds a bit on the high side (being on an island will add shipping costs / middle of nowhere fees)--I presume). -Bill

    Exactly what I have done. Nice to know I did something right. Anyway the Honda runs twice a day to charge up the batteries, house and well. The diesel runs on heavy load days, puts the inverter in charge mode, and the dedicated mains panel for the diesel livens up the circuits for washing machine and dryer, Vacuums, power tools etc. In between generator runs the houses are coasting off the batteries and inverters.

    The $5 guess comes from 2 gallons of gas, here close to $10, per day plus generator costs, batteries, battery chargers and inverters. With larger battery banks I'd have more reserve power and could cut the Honda down to once a day. On the current charging profile it's rarely putting in over 800 watts.

    Thanks for the help.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions

    Sorry, I had a typo in there... Should be around ~3 kWH to 5 kWH per gallon of gasoline with a well matched generator.

    If the cable run is "exposed" to lighting, I would put the suppressors where it goes into the basement. If you run metal conduit up to the base of the tower, I would put the surge suppressors there.

    Put some sort of Watt meter (with Watt*Hour meter too ideally) on the genset. You want to make the best use of the fuel which for larger gensets is probably around 50-80% of rated capacity. For the smaller inverter/generators, you can probably run them from 25% to 80% or so so efficiently (but running 50% or more still have better fuel efficiency).

    With the two battery bank controller, you should be able to run all power to your main bank, and just let the controller charge the second bank when the first bank is being charged.

    Lastly, running a genset to recharge deep cycle batteries >80% SOC can be a bit of a waste of fuel as the battery starts cutting back on charging current. And >90% SOC charging is probably only something that you want to do once a month/when equalizing.

    You might think about running your deep cycle battery bank at 50-80% SOC for 6 days a week, and recharge to >~90% once a week. Running the batteries with daily cycling at 50% to 80% SOC with heavy charging current (probably >>13% rate of charge) should give you higher efficiency and still give you long battery life.

    One voltage only battery monitor (from Midnite) is pretty neat because it does warn you if the battery has not been fully recharged in the last week (when the risk of battery sulfation goes up).

    Battery charging under heavy current can be hard on gensets (and apparently, even on MPPT charge controllers). If you choose to do this--Monitor the temperatures/operation of gensets, battery chargers, and your battery banks. As long as the battery bank does not get hot and/or bubble very much, you should be "in the zone".

    The automotive batteries are something you will have to monitor... You don't really want to discharge them below ~85% SOC very often, and don't recharge them much over 14.2 to 14.4 volts (and don't hold 14.4 volts for 24x7), you should float the batteries at ~13.6 volts or so after they are charged. Watch their water levels--If you have to add water every month or two, you may be over charging them (most automotive batteries are designed to not use much water--so using water is usually a sign of over charging/high float voltage).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    Looking at battery monitors.

    Presently running a mix of LED volt, Hz and amp meters from Amazon as well as the effergy system.

    I like the look of the outback Flexnet-dc monitor. Looks perfect for the two bank system here. Quick question, is the data accessible from a computer interface? It also looks like the 500 amp shunt will handle the loads from the well bank.

    Thanks.

    Note: edited to add which outback monitor.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    Ewqre the noise induced into the building from the Turbine, especially when it gets really windy!

    Tony
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions
    icarus wrote: »
    Ewqre the noise induced into the building from the Turbine, especially when it gets really windy!

    At this point, blissfully ignorant, because its such a small turbine I don't think there will be much noise. If it becomes a problem I'll move it later.

    From the generator to the charge controller I am looking at 12v AC. If I wanted to move it about 100 yards what would I be looking in wire gauge? Assuming it never gets above the rated 400 watts.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions

    I am not the person to really ask... Do you have some idea of what you want to do (integrate with your existing system, etc.)...

    Some folk here may be better able to direct you to a solution that meets your needs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Gudcraft WG400 set up questions

    400 Watts @ 12 Volts is roughly 34 Amps. Across 100 feet? I hope you're made of money because you'd need like 1/0 to keep the v-drop below 3%.

    That's another of the basic problems with these small wind turbines: their output is too low Voltage to be of any good over the kind of distance needed between them and the batteries without ridiculously large wire.
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    Current system is a hack. Working but a hack.

    As I learn what I am doing and improve on things I have some goals. One of them is to monitor energy in and out of the banks from the different sources.

    The effergy system allows me to pull up an on line portal to track 120v usage hourly for the last 24 hours, daily for the last 28 days and monthly. While it doesn't do a lot of what I need its pretty handy for tracking AC usage.
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    @BB Forgot to ask, what type of suppressors would you recommend for the wiring at the basement. I plan on using 10/3 solid from the junction box on the ridge to the box where I'll be mounting the charge controller.

    Thanks again.

    @cariboocoot, thanks. Looks like the roof mount will be a happy home. I'm sure I won't even notice the noise after a while.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions

    Again, I am not in the solar/power business... The Midnite look like some very nice MOVs protection devices (more expensive too):

    http://www.solar-electric.com/suprde.html

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    @BB. Exactly what I was looking for.

    In other news, I ran a wire calculator app over at http://www.freesunpower.com/wire_calc.php and came up with a 5 gauge wire for the 30 foot run from ridge to basement. Is this right? Figuring, 12volts, max 400 watts AC power?

    Seems excessive.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions

    How many volts do you want to "drop"? 3% is a typical number we use...

    400 amps / 12 volts = 33.3 amps
    12 volts * 0.03 drop = 0.36 volt drop

    Using a generic voltage drop calculator for 33.3 amps and 30 feet (have to put 300 feet in calculator to get extra digit on voltage drop):

    33.3 amps @ 300 feet => 3 volt drop @ 1 awg -> 0.3 volt @ 1 AWG for 30 feet

    Part of it depends on where the voltage regulator is located... Many small wind turbines have the regulator in the nacelle--And the long wiring runs make for very inaccurate battery voltage feed back unless very heavy copper cable is used.

    If you have an "unregulated" turbine, you can probably have several volts of drop and still get good current/voltage to the controller... 1.2 volt (~10% of 12 volts) -- Get up to ~14.5 volts+1.2=15.7 volt output at the wind turbine--Would that work?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    At the moment I am sizing for the roof run. About 30 feet in all.

    I'm not sure what you mean by an unregulated turbine. But I can write Gudcraft again and find out.

    Rough guess, using the 10 gauge wire over the 30 feet looks like a 10% drop in voltage? That about right?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions

    I get about 2.4 volt drop with the calculator link I provided... (it uses one way length).

    You do have to look at how they define the length... They either do "one way length" (assume wire is 2x as long) or round trip length (you have to 2x the one way run length to account for the total round trip length).

    I am guessing that your calculator needs to enter the round trip wire length.

    I also was using normal temperature--If you use higher temperatures, you will have higher resistance in the copper/voltage drop.

    If you are using only 1/2 the total wire length for a calculator that needs the full wire length, you need about 3 AWG heavier wire than you are currently estimating (in terms of voltage drop/resistance).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    OK, well emailing Gudcraft tech support is like a cross between a good-news bad-news Joke and a knock knock joke.

    apparently with my 12v 400 watt windmill I don't have to worry about anything over 20 amps. much. So that should increase the efficiency. Slightly.

    Next the two wires marked LOAD are for:
    1-Nothing
    2-Connecting to the batteries. Note there is already a circuit marked battery.
    3- Connecting to some load. if I want.
    All of this depends on which email reply I decide to pay attention to. I have an additional email in asking for clarification on some other questions, but I imagine the answers will be just as flexible.

    At this point I'll get a variable voltage power supply from radio shack and bench test the unit to see what happens.

    power wise this looks like I will be getting 240 watts at around 31MPH windspeed. With a 20% loss in transmission, probably another 10% loss in conversion brings me to around 168 watts, max from this unit.

    Is this in line with other experiences with small wind generators, or am I still setting the bar too high?

    thanks.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions
    islandguy wrote: »
    OK, well emailing Gudcraft tech support is like a cross between a good-news bad-news Joke and a knock knock joke.

    apparently with my 12v 400 watt windmill I don't have to worry about anything over 20 amps. much. So that should increase the efficiency. Slightly.

    Next the two wires marked LOAD are for:
    1-Nothing
    2-Connecting to the batteries. Note there is already a circuit marked battery.
    3- Connecting to some load. if I want.
    All of this depends on which email reply I decide to pay attention to. I have an additional email in asking for clarification on some other questions, but I imagine the answers will be just as flexible.

    At this point I'll get a variable voltage power supply from radio shack and bench test the unit to see what happens.

    power wise this looks like I will be getting 240 watts at around 31MPH windspeed. With a 20% loss in transmission, probably another 10% loss in conversion brings me to around 168 watts, max from this unit.

    Is this in line with other experiences with small wind generators, or am I still setting the bar too high?

    thanks.

    I am going to post a couple of "bad wind" links:

    Small windpower a scam ? Survey says SO
    Truth About Skystream & SWWP

    Small wind just does not perform anywhere near what the glossy brochure claims.

    I am the grumpy old guy on wind here... I am trying to set your expectations low. If you can justify the expenses to experiment--That is great.

    If you want to get a useful amount of power, you need a 60 foot tower (30 feet minimum above local obstructions). Wind maps are generally at 125 feet. You will not see anywhere near that amount of wind for more than a few hours/days a year (my guess). I have been at the top of ridge lines with 10-15 MPH prevaliing winds (San Francisco coastal hills) and "flagging" trees--It is simply a miserable place to be.

    At 31 MPH, you will only see that during wind storms, and there is a chance that the turbine will over heat, fail, shutdown in high winds, etc...

    My suggestion would be for you start with solar panels first (plus backup genset/utility AC charger, etc.)... Then look at wind as a "fill in source" during poor weather. For 99% of the locations out there, it is not practical to use wind as your primary source of power.

    -Bill

    PS: I am not really that grumpy--I just have not seen any small wind systems on short/roof mounted towers that have made any power at all--Including very expensive installations on Museums and tall buildings. You can read this "pro-wind" site about many of the issues out there.

    http://www.wind-works.org/cms/index.php?id=17

    Even the "perfect turbine" will not perform if poorly sited.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    @BB
    Here is my thinking here. Since I work in IT, I never actually believe manufactures claims, if you think wind and solar are bad, try software manufactures. So I figured the 400 watts would be less. Not a problem. Like I said this is an experiment.

    In my area, an island, we have lots of wind and fog. So I figured a windmill would be the way to go.

    In doing my homework I went to weather underground, around half way down the page you can click on a view calendar link, go to custom, select the dates and pull up years worth of weather information. Including wind.

    With this information I guesstimated an ROI for the wind generator. Taking it as a given that the ROI period would be somewhat flexible.

    Since this is to be an out of pocket experiment I selected the windmill strictly on price. Probably should have spent a little more time researching this point.

    Anyway I now have a small windmill that should produce some power. Because of zoning here I am pretty much stuck with small windmills. A four foot blade span is probably the most I could get away with here. The other problem is that I will not be able to put it high enough for undisturbed air.

    So at this point I'll still mount the windmill and review how much power I am getting from it. Initially with an amp meter, then maybe something better down the line. I still expect it to generate enough power for an ROI, but whether I hit that point before or after the heat death of the universe might be an issue.

    Thanks again for the help and info.

    Also, how do people use small, under 1Kw, windmills and transmit power? The only thing I could think of was to place a small battery and charge controller at the base of the tower. The either a 110v or 220v inverter for transmission of the power to a battery charger and main battery bank. seems like there would be a lot of power loss in converting from all of the different voltages. Then of course line loss in transmission.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions

    If you can find/build a wind turbine that will operate near 100 VDC--or even somewhat higher (after rectifier output), you can use the Midnite Classic. The MPPT will take the high voltage/low current from the turbine and efficiently down convert to low voltage/high current used by the battery (basically a switch mode power supply in the classic does the power conversion). Makes sending power the 100-200 feet or so required with turbines much easier.

    If you are stuck with 12 volts, the MorningStar 300 Watt TSW inverter (in 120 VAC 60 Hz or or 230 VAC 50 Hz) would be interesting. It has a 12 volt remote on/off input that you could use to control the inverter--And put a battery charger at the far end. Turn on the inverter to run the "dump load".

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • islandguy
    islandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: Gudcraft WG400 set up questions

    I took a quick look at ebay and came up with some grid tie inverters but he Morningstar looks like the way to go.

    I like the idea of powering the inverter off the dump load since I couldn't think of an easy way to keep the battery charged. My questions are now finding out if the
    dump load is the same voltage and what battery charger to use for the variable amperage. I'm not sure the powermax I have will be up to the challenge since I have already fried three of them.

    Thanks again, this is beginning to look interesting.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Gudcraft WG400 set up questions

    Very rugged AC Battery Charger is the Iota--It does have an input that you can set for two voltage levels--One is float (input open) and the other is moderate charging (something like 14.5 volts or so for a 12 volt battery). One poster here said that you can remove the chassis and there is a 10 turn pot that you can use to adjust the output voltage.

    http://www.solar-electric.com/bach1.html

    I am not sure you if you want the IQ4 module or now--It really depends on how much wind power you end up producing (i.e., many hours per day, you don't want to overcharge your main battery bank).

    You can talk with our host NAWS, they seem to always fall back on the Iota as being reliable and easy to get. They have had listed other AC chargers at times, but they do not have any alternatives listed at this time.

    You should still have a true dump load + controller at the remote site... For example, set the exported load to 14.5 volts and the backup dump load for 14.8 volts (to a local resistance heater). And have a light/alarm/etc. that turns on when the backup dump controller is active (so you can check that all is OK--Don't want to boil the battery bank dry/start a fire). Having a backup dump controller+load is required by NEC to reduce the chance of fire if one of the dump loads/controllers fails.

    For example, if you want a 300 watt load:

    300 watts * 0.80 charger efficiency * 0.67 PF * 1/14.5 volts charging = 11 amps @ 12 VDC charge controller

    Note that the 0.67 PF and even the 0.80 battery charger efficiency is up for discussion--The math/engineering would usually support such numbers. But one poster that I respect here (Blackcherry04) has done experiments that show the above numbers are too pessimistic (and others have found the pessimistic numbers are valid). You can try a 15 amp @ 12 volt AC inverter with a 300 watt AC inverter (or larger) and do your own measurements.

    The MorningStar is a pretty rugged inverter, but long term power transfer near rated output is hard on many "consumer" grade electrical devices (and generators). Unfortunately, you will probably have to spend some time/money experimenting with different chargers/inverters/power controls (and make sure everything has good cooling airflow) to get a reliable installation.

    Note that the efficiency is terrible. You are losing about 1/2 of your energy due to conversions. If you can justify the costs of a Classic+Clipper+ higher voltage wind turbines--You should harvest a lot more power.

    For an experiment--The above (small inverter + small battery charger) will work.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset