12v DC wind turbine - and connecting straight to 2 large 12v batteries.

It depends on your wind turbine... Some have internal battery charge controllers. Others need an external controller.

The "typical" setup is Wind Turbine -> rectifier -> battery bank -> Diversion Controller -> resistance heater

The idea being that most wind turbines will over speed in high winds if they are not loaded (connected to a working battery bank). When the battery bank is full, a diversion controller "turns on" and dumps current to an electrical heating element. When the battery is less than 100% full, then diversion controller turns off and the battery is charged again.

And you would keep your solar panels+charge controller connected as it was (directly to the battery bank). The solar charge controller will turn the panels on/off as needed to keep the battery bank charged (assuming you have enough sun+solar panels).

Wind turbines are not usually the easiest/best way to help charge your battery bank (a tower to hold the turbine, and the wiring+charge controllers for wind turbines are not cheap--plus most people do not have enough wind on site).

But since you already have solar panels (and perhaps you may want to add more)--Experimenting with a wind turbine as an additional power source may be helpful for you.

-Bill

OK... Lots of questions there.

If you put a charging source across the 12 volt segment of a 48 volt battery bank--You will simply charge just that segment of cells (assuming that both the + and - charging source leads are floating, and NOT ground referenced).

Charging just a 12 volt segment of a 48 volt battery bank does not help much of anything... The rest of the 36 volts worth of cells have not been recharged.

You do have options... You can charge a 12 volt bank and use a 12 volt to 48 volt converter to charge the whole 48 volt bank (you may be able to find a 12 VDC to 48 VDC converter and directly connect, and bypass the 12 volt battery bank).

There is another "interesting" method of charging/discharging a "split battery bank". Used in heavy duty vehicles/RV conversions (bus/truck conversions)--24 VDC vehicle chassis and a 12 volt "house power" (RV inverter, solar/wind charger/etc.).

You connect a 12 volt to 12 volt isolated DC converter across the A and B battery segments. The DC converter keeps "equal voltage" across the two halves of the 24 volt battery bank. This allows any combination of 12 and 24 volt loads/charging sources to use the bank "optimally" while the isolated DC to DC converter tries to keep the voltage of Bank "A" equal to the Bank "B" voltage. The DC converter can move energy in either direction.

You do not want to "unbalance" a string of cells/batteries (tap 12 volts from a 24 or 48 volt battery bank). Very difficult to get the batteries back in balance... And the battery bank is only as good as the "weakest" cell/battery.

The output voltage of an alternator is, more or less, proportional to RPM. Spin the alternator 2x faster, the open circuit output voltage doubles too.

Current output is also proportional to RPM (faster RPM, higher output current). A 12 volt alternator can output 60 to 100+ volts if the RPM is high enough.

Of course, you need the alternator to overcome rectifier/wiring resistance. So, while the alternator may generate (random example) 40 volts open circuit at 400 RPM, it will only output 45 Amps @ 12 volts at 400 RPM.

http://www.windynation.com/jzv/inf/open-circuit-voltage-and-short-circuit-current (nice chart 1/2 way down page)

-Bill

Assuming this is a horizontal axis wind turbine with a rectified (DC) output voltage connected to the battery bank, you would need a "dump" controller connected to the battery bank and a resistor (heater) bank to absorb the excess charging current from the wind turbine (battery full, need to dump power somewhere to prevent the turbine from overspeeding).

And, yes this can be done in parallel with the solar charge controller.

-Bill

Willsio,

As always, the devil is in the details. If you have more questions, I suggest you open your own discussion and we can help you there (easier to keep all questions and answers related to your needs).

There are lots of rules of thumbs that we use to "size" and design a reliable/cost effective system. It is possible, if you do some of these wrong, to create a fire/safety hazard with your system (wind systems can be very difficult to make safe and reliable--Many times, adding more solar panels and/or a backup genset is a better solution).

-Bill

No worries... English (or at least "American") is my native and only language--No good excuses why mine is so poor.

-Bill

While it is technically possible to design such an off grid AC inverter--I do not know of any (perhaps somebody can let us know of any such inverters).

There are Grid Tied inverters that can take output from wind turbines and connect them to the utility grid (or even "micro grid" installations that use a TSW off grid AC inverter).

You want to run CFL lighting from the wind turbine? That seems to be something that is not going to be very successful. A wind turbine has highly variable output and the bulbs will flicker/dim/brighten/etc. depending on wind/gusts/becalmed conditions.

If you want to discuss your needs/ideas in further detail, please feel free to start your own thread. It is usually easier to keep all of your questions and answers in "your thread".

-Bill