Generator to charge solar batteries

Perch
Perch Registered Users Posts: 11 ✭
in General Solar Power Topics #1
I have a very small solar system at my cabin: 200w of panels, a ProStar controller and a couple batteries that I use to run some 12v lights in the evening amd recharge my cell phone.

I also have a generator that I run a couple times a day to drive the pump that fills my water tank.

Having just been through several days of rain where solar wasn't keeping up, my question is this: if I were to hook a battery charger like an Iota up so that my generator would add some charge to my batteries while it's running would I cause any harm to the solar side of things?

I know relatively little about solar systems and hope someone here can help.

Thanks.
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  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
    #2
    Re: Generator to charge solar batteries

    I'll let the other guys guide you on the Iota.

    But first, what exactly is your battery setup? Capacity, chemistry (flooded, agm), single battery or some multiple configuration?

    How many 12v lights do you have, how long do you actually run them, and what is the wattage or current rating?

    Also, where are you located? Knowing your solar-insolation hours, which differ from sunrise-to-sunset is crucial and one can look up online or we can find it.

    And, as I've experienced recently, are you suffering voltage drops by having your controller located too far away from your batteries with insufficient wire gauge?

    Aside from that, welcome aboard! :)
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  • Perch
    Perch Registered Users Posts: 11 ✭
    #3
    Re: Generator to charge solar batteries

    Well, I've put some of the answers below. However, I probably wasn't clear in my question. I'm not looking to change or expand my solar setup. I'm just wondering whether grabbing some of the "extra" generator power to help out on long stretches of rainy days will damage my controller. If so, I'll put some kind of transfer switch in place.

    I have two 225 Ah flooded 6v batteries in series. The number of lights varies by who's around but maxes out at 8 lamps, each with an 11w compact fluorescent 12v bulb. I'm located in central Maine. Some of the runs probably experience some voltage drop...I think the longest is about 30 feet of 10 gauge wire...but things generally work quite nicely unless I get a several rainy days in a row.
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #4
    Re: Generator to charge solar batteries
    Perch wrote: »
    I'm just wondering whether grabbing some of the "extra" generator power to help out on long stretches of rainy days will damage my controller.

    Welcome to the forum,
    Generally, it's almost never a problem. When it is a problem, it's often because of the way the system is wired.

    Does your system have an inverter?

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • Perch
    Perch Registered Users Posts: 11 ✭
    #5
    Re: Generator to charge solar batteries
    vtmaps wrote: »

    Does your system have an inverter?

    Only occasionally. It generally does not have one connected as everything I need is 12v anyway. When my wife needs to work and brings her computer, I have a Samlex inverter that I connect directly to the battery.
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #6
    Re: Generator to charge solar batteries
    Perch wrote: »
    Only occasionally. It generally does not have one connected as everything I need is 12v anyway. When my wife needs to work and brings her computer, I have a Samlex inverter that I connect directly to the battery.

    The reason I asked about the inverter is because how the charger, controller and inverter are wired can affect performance. All devices should be fused and directly connected to the battery (or better yet a battery bus bar). Problems occur if, for example, you connect the inverter to the battery and then connect the charger to the inverter, rather than directly to the battery.

    Speaking of which... I hope that you are not making temporary connections of the samlex with alligator clips.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • Perch
    Perch Registered Users Posts: 11 ✭
    #7
    Re: Generator to charge solar batteries

    Nothing is alligator clips. :-)

    The charge controller is connected directly to the battery with lugs crimped onto the end of the wires. I connect the inverter with an Anderson Power Pole, the battery side of which is also connected with lugs. Those are the only 2 things connected to the battery at the moment as the lights run out of the Load set of connectors on the controller. I wired a fuse into the positive wire going to the inverter and the cutoff switch I put between the controller and the battery is fused.

    I've been debating buying/making a pair of bus plates so that I don't have to stack a lot of lug connections onto the battery terminals.
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #8
    Re: Generator to charge solar batteries
    Perch wrote: »

    I've been debating buying/making a pair of bus plates so that I don't have to stack a lot of lug connections onto the battery terminals.

    What's to debate? Do it! --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • Slappy
    Slappy Solar Expert Posts: 251 ✭✭✭✭✭✭
    #9
    Re: Generator to charge solar batteries

    Bus bars makes wiring so much easier. I would recomend it. I use to stack the wires on the battery term. Did for many years then the stacking gets out of hand over time.
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