Newbie charge controller question
silent57
Registered Users Posts: 2
Hi everyone. I'm very new to the wind and solar power scene. I haven't bought anything yet, just trying to learn first. I have a question about charge controllers. Excluding MPPT controllers, do typical charge controllers (say from missouri wind and power) regulate the incoming voltage from the wind turbine? For example, lets say I have a turbine generator that used to be an old treadmill motor. Now lets say that this motor typically puts out 40 volts. Will a normal charge controller that's not MPPT take that 40 volts and make it suitable to charge a 12 volt battery bank? Remember, this is just a hypothetical situation. If it's too much voltage for a 12v system, I would also think that it is too much for a 24v system, but not enough for a 48v system.
A slightly different but similar question is, can a professionally made 48v PMA charge a 12v battery bank as well as 48v? Or can it only charge 48v banks? I appreciate any help on how a typical non MPPT charge controller works. I have done some research on my own, but all the information I find makes it sound like the charge controller only regulates the charge on the battery and not the incoming charge from the wind turbine. If I got a hold of an old treadmill motor and it creates 40v I just don't want to be putting 40v directly into a 12v battery bank. I don't think that's okay anyways.
A slightly different but similar question is, can a professionally made 48v PMA charge a 12v battery bank as well as 48v? Or can it only charge 48v banks? I appreciate any help on how a typical non MPPT charge controller works. I have done some research on my own, but all the information I find makes it sound like the charge controller only regulates the charge on the battery and not the incoming charge from the wind turbine. If I got a hold of an old treadmill motor and it creates 40v I just don't want to be putting 40v directly into a 12v battery bank. I don't think that's okay anyways.
Comments
Welcome to the forum.
The answer is "yes, but no".
Typically a wind turbine controller does not interrupt power to the batteries thus regulating the Voltage. Instead the full output is put to the batteries, causing the Voltage to become a current and force the battery Voltage up. When it reaches a set level, the controller then connects to dump load which "drains off" the excess power keeping the Voltage at the correct level. This is known as "diversion control". You can see a basic diagram of this type of use on Page 2 of this data sheet from Morningstar: http://lib.store.yahoo.net/lib/wind-sun/TSdatasheet.pdf
As such, having the Voltage potential of the turbine too far above the system Voltage can cause trouble in the form of too much current. Hence the need for a more complex set-up such as a MidNite Classic http://www.solar-electric.com/misocl.html combined with their Clipper http://www.solar-electric.com/miso1waactuc.html
NEC regulations, btw, require redundant diversion control on turbines in case something goes wrong with one of them. Otherwise the turbine can "spin free" and really create problems.
It is unlikely that a turbine made out of an old motor is going to give you much power or for very long. They simply are not designed to sit out in the weather and churn out power 24/7 no matter what modifications you make to them.
Thanks for the quick reply. The info helps a lot. I've heard of many people using treadmill motors as generators. I just wanted to save a few dollars, but maybe I should stick with a professional setup. Thanks again, I appreciate it.
Please note--I am not a fan of small wind in general. In the right hands. There are a few vendors that make make good equipment, but one of the best installations I have read here was with DIY turbines (Chris Olsen is not your typical shade tree mechanic), and with 60-90+ foot tall towers and a really windy region, they can be a nice addition for off grid power).
Marc's (Cariboocoot) suggestion of the Midnite controller system could be very good fit for a 48 volt turbine powering a 12 or 24 volt battery system. MPPT type charge controller can efficiently "down convert" high voltage/low current from the Panels or Turbines to low voltage/high current needed to run a battery bank.
These are usually not cheap or small systems... And if you are looking at over 1,200 watt of average power from the battery bank and/or over a 600-1,000 AH 12 volt battery bank, you should be looking at 24 or 48 volt battery bus voltage.
In general, if trees in your area are not "flagging" from prevailing winds, you probably do not have enough wind. Most turbines do not begin to produce any power until 10+ MPH is reached. And most turbines max out around 28-30 MPH (which, for many turbine designs, means they do not produce any useful power in very high winds as they need to shut down for protection).
Even our own host, Northern Arizona Wind & Sun is looking for a good wind turbine that they can sell and support (by the way, the "moderators" here and the rest of the posters here are "volunteers" for the forum and have no direct connection with our host NAWS (Windsun is our Admin and is with NAWS)..
So, some quick links for you to look through:
http://dairylandwindpower.us/ (Chris Olson's website--Real off grid with lots of power usage--even using electric stove and drier).
In general, the recommendations for how to proceed:
Your thoughts?
-Bill