Building a new Solar Lighting system. Need advise.

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lavsan
lavsan Registered Users Posts: 5 ✭✭
in Solar Beginners Corner #1
Hello everyone

I am new here and am looking for advice on building a solar lighting system for my house.
Here is my plan.

I basically want to charge A couple of Panasonic 18650 cells (3100Mah) using a 20W solar panel. via a converter that changes 12V to 5V 3A.And finally light up some Led Bars.

Details:

1. Solar Panel: The following are the Specs of the Panel i am planning to use


Solar Panel of 12Volts 20Watts.
Specifications
Rated Max Power (Pmax): 20W
Current at Pmax (Imp): 1.124A
Voltage at Pmax (Vmp): 17.8V
Short-Circuit Current (Isc): 1.308A
Open-circuit Voltage (Voc): 21.4V
Normal Operating Cell Temp (Tnoct): -40C~50°C

2. I want to Use this Item in order to be Able to charge the 18650 Battery Pack (Check point 3)

link to the Ebay item
http://www.ebay.com/itm/DC-DC-12V-24V-Stepdown-to-5V-5A-25W-Car-Power-Supply-Converter-/221205568076?pt=LH_DefaultDomain_0&hash=item3380e11a4c

convi_zps45ab8236.png

Features:
Input voltage: 12/24V (8.0V-40V)
Output voltage: 5V
Output Current: 5A
Output power: 25W
conversion efficiency: 96%
heating value:under 60℃
Waterproof design
Short-circuit protection and automatic recovery
Small Dimension:58X40.5X20mm

3. The purpose is to charge this 18650 Pack which will hold 4 18650 cells.

Link to item on eBay
http://www.ebay.com/itm/Dual-USB-18650-Mobile-Power-Battery-Box-Charger-For-Rechargeable-Li-Ion-3-6-3-7V-/330880171043?pt=Battery_Chargers&hash=item4d09febc23




Specifications

.Charging input: micro usb: 5v/2A
2 Total output current regulation: usb1 + usb2 = 0.5A/1A/2A ( adjustable)
3 Four power level display (25% red, 50% green, 75% green, 100% green)

Battery Type: 18650 lithium battery is 3.6-3.7V battery than ordinary batteries (18650 diameter 18mm long 65mm cylindrical battery)

Technology:
Charging input: micro usb: 5v/2A
2 total output current regulation: usb1 + usb2 = 0.5A/1A/2A (adjustable)
3 four power display (25% red, 50% green, 75% green, 100% green)


4. It has to be Able to light up 3 or 4 of these Units.

Link to item on eBay
http://www.ebay.com/itm/251198197831?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D251198197831%26_rdc%3D1



lightll_zpsd5d62532.png

This item has a lithium ion battery biuld in which can last upto 10Hrs when fully charged. I,ll just connect the Output from item no 3 to this unit with a switch in between.
It runs on a 3.6 Volt system. I am going to take out all the electronic components repack it and Just use the led and the reflector surface while its being powered by my 18650 Battery pack.
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I need some advice on how to make this work.
And if there are any changes that are required to make it work.
All suggestions are welcome.

Thank you in Advance.
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Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
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    Re: Building a new Solar Lighting system. Need advise.

    Welcome to the forum.

    I think we need to examine an issue you may have overlooked entirely: how long are the wire runs from the batteries to the LED's? You're looking at very low Voltage here, so unless you were planning on physically moving the lighting units to a charging station as needed you probably would not have any power by the time you reach the end of the wire.

    Also, those lighting units describe being plugged in to household power for recharging.

    Sounds to me like you're trying to get mice to do the work of horses, but I'm sure some of the guys on the forum will want to look over the specs and see how workable a solution this is.
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  • lavsan
    lavsan Registered Users Posts: 5 ✭✭
    #3
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    Re: Building a new Solar Lighting system. Need advise.

    Thank you for taking the time to reply.
    Actually there was something missing in my post. I am writing it here & i have updated it on the post as well.

    I am going to take out all the electronic components repack it(item number 4) and Just use the led and the reflector surface while its being powered by my 18650 Battery pack.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
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    Re: Building a new Solar Lighting system. Need advise.

    Just to be clear: are you talking about running 5 Volt wires from a central battery pack to the lighting units?

    Practical advice: buy one of the lighting units first and see if it actually produces enough light to suit your purposes. Maybe you already have.

    Many of us (especially those with "more experienced" eyesight) would probably find them insufficient for lighting a house.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #5
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    Re: Building a new Solar Lighting system. Need advise.

    this may raise a question when it comes to the regulator and pv choices as the regulator will most likely be linear and would pass the current straight from the pv at what the pv is capable of delivering, which for that pv choice is 1.124a. the charger itself requires 2a and this may push your pv requirement to around 40w.
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  • lavsan
    lavsan Registered Users Posts: 5 ✭✭
    #6
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    Re: Building a new Solar Lighting system. Need advise.

    yes i am planning to run 5v wire from the Battery pack to the Led unit. the led unit operates on 3.6 volts.
    so even if there is a drop in voltage i expect it to work.

    the led Bars are quite good for the size they are and my purpose is not to have light for reading or such but just to illuminate the Space and make it workable.
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  • fivewin
    fivewin Registered Users Posts: 1 ✭
    #7
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    Can you pls give an update. Is your project succesfull?
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