Solar combined with wind power

kswisonkswison Registered Users Posts: 6 ✭✭
Hi, I have a few questions. My questions are in BOLD

My system is in my RV. 

I have a solar system set up with 2 260W panels (total 520w) on a 60a iTracer solar controller.
I have a bank of 4 T105 Trogan 6V wired for 12V power. So max solar charging 43.3 amps.

I recently bought a 400W Max wind turbine that is 12V, (that will charge at 33.3 amps) but not hooked up yet. I am told that with the 12V turbine, if I install a diode on the positive wire from the turbine, that I can hook the wind turbine directly into the battery bank. However....

I have read that having two charging systems (wind and solar) can mess each other up, as one system might sense the batteries being full and shut down, as the charge voltage is higher from the other system. Basically confusing it and shutting down. However, I also know that (in my location) that when the sun is out the wind is usually down, and in winter months the sun hours are short and the wind blows more. Basically, I am really looking to have the wind turbine top up everything in the winter month (when sun hours are shorter and there is more wind). 

I am basically convinced that this will work (direct wired) and that I really should not have no issues, as both sides of the charging systems have regulators to turn of solar charging or break the turbine. As well the systems will likely be charging at somewhat different times. So I should not over charge a battery bank. I think that all works.-

Here is where it gets complicated.

I have a second smaller solar system in my shed. There I have 2 smaller 40w panels (total 80W, with max charging at 6.6 volts) on 2 older 12v deep cycle batteries. Basically a system made out of parts I had lying around. I have a 10A solar controller on each solar panel to regulate each panel separately. Both connected to the second battery bank. So all good there.

However, what I am trying to figure out a way to have the wind turbine tied into both systems. 

I am thinking that if I install a battery isolator on the power supply from the turbine that I can have the line split to both battery banks, but the batteries will remain separated by the isolator. My system in the RV will charge as noted above. As well the system in the shed will charge in a similar manner.

Where I get hung up is, the wind turbine's regulator monitors the batteries charge, and once full, the turbine breaks to stop charging. However, in this scenario, if the battery bank in my RV is at capacity from the solar charging system, and the one in the shed is not, i am assuming that the charge from the turbine will still end up going to both batteries and might overcharge (boil) my battery bank in the RV.

I do not see how this could not happen. So it is my opinion that I need to have a solar controller on the turbine's power supply installed on each line after the battery isolator. That will prevent over charging on both banks.

However, as the turbine is 400w max, its charging amps are 33.3 amps.

Question 1) Do I need to have 35 amp solar controllers on both those lines from the turbine ?

I assume that as one controller could be shut down, that the full charge would go to the other, so max'ing out at 33.3 amp to one battery.
I thought about using two smaller 10 amp controllers, but am concerned that they would burn out. Would they ? As well, they would substantially reduce my wind charging ability. 

I see I can buy some 40A solar controller off of e-bay for about $30 each. So I guess that is the way I will go. So I guess I answered my owner question there.

Question 2) 
This is were I have no idea.....

I know that my RV battery bank will be fully charged while I am away, as there is no draw on it while I am away, with lots of charging.
The shed has continuous draw on it and its a smaller solar system.
Is there a way to have the RV battery banks help to charge the shed battery bank without connecting them directly.

The concern is that my RV batteries are new and the shed batteries are old. The old batteries will suck down and deteriorate the new batteries. So I do not what to do this.

I do not have a solution for this.

Currently, I only have only one buried line (+/-) between my shed and RV. The wind turbine will be mounted on the roof of the shed. I want to use that buried line for the turbine to assist in charging the RV battery bank during the winter months, taking power back to the RV. I would have to bury another line (+/-) to have the RV bank charge the shed's bank, if that is possible to do that without deteriorating the RV battery bank.

Alternatively, I could just use that second buried line to possibly power more of the continuous draw items in my shed. But when I take the RV on the road, there would be no power to those items. I guess an over-ride switch could deal with that when the RV is gone. 

However, I would prefer to have the RV battery bank simply help to charge to shed battery bank. 

I have considered a solar controller on that line from the RV batteries to shed batteries, but its not an issue of over charging there. Its an issue of deteriorating the new RV batteries. So I don't think that will work.

I could put a current diode on that line, but that just controls the direction of current, so that will not solve deteriorating battery issues either.

Anyone know what I can do here, or does this simple need to remain separate ?

Sorry for the length of this, but I have been struggling with this for a while now. Maybe I already know the answer. :)

Thansk in advance.


  • SolraySolray Registered Users Posts: 246 ✭✭✭
    I would get a new charge controller with a hybrid set up for leads from both PV panels and turbines on the controller. It will have the needed circuits built into it to work with both systems.
  • kswisonkswison Registered Users Posts: 6 ✭✭
    I resolved this buying a battery isolator (like for a motorized camper)  where the alternator charges both batteries but keeps the batteries separate. One battery bank will not drain the other. I put a solar charge controller on each line after the isolator. That all seems to work well. I did not find a way to have the RV bank charge the Shed bank. Looked like anything I tired would drain the RV batteries down to the poor shed batteries so I abandoned that idea.
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