what else do i need

System Posts: 2,511 admin
I just ordered a Kyocera KC65T Solar Panel 65 Watt, 12 Volt. What kind of charge controller do i need, or whatever else should I get


  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    Re: what else do i need

    We need to know what your plans are. Lights,pump,battery charger, etc.
  • System2
    System2 Posts: 6,290 admin
    Re: what else do i need

    sorry I have my camper parked at my shop and we go out there on the weekends and stay, I would like to move my camper to the back lot but do not want to run wire that far. we are going to use the basic lighting at night and when my kids go with probably the tv, dvd, and or the ps2. mainly at night. thanks
  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: what else do i need

    You need a charge controller and some batteries, then an inverter to convert the 12v from the batteries to 120v.

    Probably a lowbuck charge controller from our hosts at WindSun will be fine. PWM should be good enough.

    Most lowbuck inverters are Modified Sine Wave type, and they can do bad things to some electronics...as well as making fans hum and whatnot. I use a 200w MSW in my RV for my laptop and it works fine, but I dunno if I'd trust a MSW for a PS3. You might want to get a Pure Sine Wave type inverter - but they are pricey.

    Figure out how many amps the lights, TV, PS3, whatever will draw and how many hours they will run and you will know how many amp/hours of batteries you need.

    Then multiply that times 10 for the 120v loads since you are drawing from 12v instead of 120. Now you know what size batteries you need.

    Then double that since drawing the battery down below 50% will shorten it's life.

    Then figure out how many amp/hours you will get out of that 65w panel and you'll probably find that it won't be enough to recharge the batteries before the next weekend session comes along.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Re: what else do i need

    In reality--you probably would be better off getting a 150' extension cord (or whatever you need) and run it to the trailer. The amount of power you (appear) to be needing will swamp what a 65 watt panel can supply.

    To start, since most of your loads are 120 VAC 60Hz--Get yourself a Kill-A-Watt meter for ~$30 or so... And measure your loads. Peak Watts, average watts, and watt*hours per day.

    wind-sun_2050_2425819Kill-A-Watt AC Power Monitor Meter
    P4400 Cumulative Killowatt-Hour Monitor

    And, once you know how much power you need, you can work backwards on how much battery / solar panels you will need to support your loads.

    Also, the Kill-A-Watt meter is great for use around your home too. The first tool anyone needs to see how much that old fridge/freezer is costing you, etc.

    In the end, you are probably paying about $0.10 to $0.20 per kWhr for Utility Power. For off grid power, you will be paying ~$1-$2 per kWhr.

    For example, a 65 watt panel used off grid during the summer (~5 hours of full sun per day), and ~52% efficiency (panel rating to usable AC output)--you get (very rough approximation assuming sunny weather):

    65 watts * 5 hours of sun * 0.52 eff = 169 watt*hours

    If your TV takes 50 watts and your PS3 takes 50 watts (assuming 100 watt load):

    169 Watt*Hours / (50 watt + 50 watt) = 1.69 hours or 1:41 run time

    Probably not enough to keep the kids happy for long... ;)

    You can guess you have ~4 days of sun (2 days on the weekend, + 2 days to recharge)--so you can probably run it for 6-7 hours for the whole weekend (if my power usage guesses are anywhere close)--But, if you can drag out an extension cord (or bury some 10-12 awg direct burial wire with two hots, neutral and ground)--you would be much happier.

    In the end, adding solar panels and reducing your loads/expectations is the only way you will get longer run times from your system.

    If you want to set the trailer up for dry camping too-then you will need to go through your dry camping loads once more and see what you need/can support.

    Here is a thread from Kevinhenrycalgary who installed a nice little system in his camping trailer and did a video showing how it was done and how it works (using upscale charge controller and battery monitor).

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