Solar/Battery installation ...

Discussion in 'Power - Site Power/Batteries/Generators/Solar' started by Katie Tanner, Jun 26, 2019.

  1. Katie Tanner

    Katie Tanner New Member

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    Hello all! Looking for advice on getting set up with a solar panel/battery operation for our pup. We have no idea where to start ... amazon, youtube, and Google are overwhelming!! We just want to be able to power a fan and charge small devices, so nothing major. Any help as to watts, amps, etc ... or links would be so helpful. We don't have anything purchased yet, so all help is appreciated! Thanks!
     
  2. Eric Webber

    Eric Webber Active Member

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    Look at Renogy. They have kits to get you started with all the wires, charge controller, and panel. A suitcase at 100w would be great and 200w is a bit more than probably needed but not much more (per watt)
     
  3. Grandpa Don

    Grandpa Don Active Member

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    Yes... Renogy. I got a 100 watt Solar kit for my camper from them. I think it was a complete kit for about $180.00. You will need more than just a Solar panel. So get a kit. No bad to install, but be sure to follow the instructions. You can make some mistakes. I love mine. I called their Tech Support for advice.
     
  4. brwarrior

    brwarrior Active Member

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    For a group 24-31 single battery look at 100 watt kits. "Rule of thumb" is 1 watt per amp hour of lead acid battery. More power and you risk boiling the battery too often.
     
  5. Eric Webber

    Eric Webber Active Member

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    For battery consumption and capacity, I find it much much easier to think only in terms of watts.

    For quick and dirty math, ignore small inefficiencies and assume you have in watt hours (watts running for one hour) half of whatever your battery capacity is in amp hours.
    This is because you don’t really want to ever go below 50% charge unless you pay for a battery designed for deeper discharge (like a Trillium Lithium)

    So, watts is amps x volts. Watt hours is amp hours x volts.

    Lets say your battery is listed as 100ah at 12v. That’s 1200watt hours to completely flat, with about 600watt jours usable (50% usage)

    There are lots of tables around showing different consumption but if you know that an LED fixture burns 10watts, running it for an hour is 10watt hours consumed. So, if you use nothing else, you can hope to run it for about 60 hours before you’d have to shut down or 120 hours before actually killing the battery

    Using an inverter (to use the battery for 120v things) is less efficient then directly using 12v. I don’t know how inefficient but I figure it’s better than half. So, running a 1000w coffee machine through an inverter that can handle it, wired using thick enough gauge wires to the battery, is going to burn through the available battery capacity in about 20-30 minutes.

    On the charging side, let’s assume you get about 75% of rated capacity in reasonable sunlight. Maybe you moved the panels into a clearing because you bought the suitcase panel. So 75 watt hours every hour on a 100w panel (ish- efficiency is more complicated)

    So about 8 hours or so for your 50% battery to be back up to about full. Ish.

    Lights and device charging (don’t step up to 120v and back down to 12v - get a 12v charger for phones and stuff. Maybe a cigarette lighter outlet) use a small amount of power. You might already have enough for that plus occasionally running the furnace (fan is battery) and the gas detectors and be able to run for 2-3 days without any recharge (again, depending on battery capacity). If you can get in a good charge or two in that period, you can run indefinitely.
     
  6. Grandpa Don

    Grandpa Don Active Member

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    :smiley::smiley::smiley:
    The man obviously knows his stuff. But oh...I have a headache now.
     
  7. Eric Webber

    Eric Webber Active Member

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    Sorry
     
  8. Eric Webber

    Eric Webber Active Member

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    Rewording for simplicity

    1. No number is ever accurate because they can’t factor in all the ways you can lose efficiency. Just halve everything and know you’ve built in some padding.

    2. Think in watts and watt-hours (watts per hour). A watt is power being used in a given moment. A watt hour is that amount of power consumed or consumable in one hour.

    3. Volts times Amps gets you watts. Volts times amp hours gets you watt hours

    4. Solar starts in watts so the math is already done for you there but it’s “happy path full of unicorns” best case optimism.

    5. There are so many competing « standards » for solar that Renogy kits are the most beginner friendly

    6. Inverters suck a lot of power. Avoid them if you can. I still use my Nespresso machine in the morning with a very big inverter but I also have a big battery setup and a 200w suitcase panel - so... you do you.
     
  9. Katie Tanner

    Katie Tanner New Member

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    Wow - thanks so much for all the info!! We'll definitely look into Renogy. Really appreciate this!
     
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  10. McFlyfi

    McFlyfi Active Member

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  11. SteveP

    SteveP Well-Known Member

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    The place to start is with the battery. The best solar kit in the world cannot make up for a battery that is undersized, improperly maintained or nearing end of life. Please read The 12 volt side of life for a better explanation than I can give you.

    Your vintage Palomino probably doesn't require a heavy 12 volt load so the fan is going to be your biggest concern. Pay attention to the power draw on the fan you choose and get the most efficient you can. My personal preference is the O2Cool fan which runs on D cells and doesn't affect the battery at all, but Debi prefers something a little stronger.
     
  12. Grandpa Don

    Grandpa Don Active Member

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    The renogy 100 Watt kit that I installed has a Solar controller that has a battery temperature sensor option that will shut down the power is the battery gets too hot.
     
    Eric Webber likes this.
  13. Stamourowl

    Stamourowl If it involves dogs and hiking count me in.

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    I get it! That you so much for explaining!
     
  14. SHFL

    SHFL Active Member

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    Yes, thank you!
    You have pointed us in the right direction to get started!
     

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