Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Solar Lighting

mosfet123

Junior Member level 1
Joined
Oct 13, 2020
Messages
17
Helped
0
Reputation
0
Reaction score
1
Trophy points
3
Activity points
104
Hi;

I have 30W 18V 1,6A solar panel and I have 12,8V 36Ah LiFePo4 battery. I want to use for lighting fixture (about 25W). is this solar panel enough for charging to battery ? and ıt should be work 3 days at cloudly days . Does anyone have an idea ? Finally is this system ok ?
 

KlausST

Super Moderator
Staff member
Joined
Apr 17, 2014
Messages
18,415
Helped
4,113
Reputation
8,226
Reaction score
4,047
Trophy points
113
Activity points
121,223
Hi,

Calculate the energy you need for the light. (over 10 days) I gues it wont be on for 24/7...
Calacualte the (expected, but low) energy you get from the solar panel. (over 10 days). Search the internet, there will charts for expectable power for your region)
--> If you get less than you need: either change the solar panel or the light.

Calculate the energy you need for the light. (over 3 days)
Calacualte the (worst case) energy you get from the solar panel. (over 3 days)
--> the difference energy needs to be supplied by the battery.
--> calaculate Ah of Battery

Klaus
 

Easy peasy

Advanced Member level 5
Joined
Aug 15, 2015
Messages
2,672
Helped
955
Reputation
1,910
Reaction score
952
Trophy points
113
Location
Melbourne
Activity points
14,996
If we assume no charge for 3 cloudy days, the light, 25W has to work over at least 3 cloudy nights, say 12 hrs per night, this is 900 watt hours.

Say the battery is a 12.8V Li-ion, 900 watt / 12V = 75 amp hour minimum.

If you want a full recharge of the system on the next sunny day, again you need to input 900 W-hrs into the battery in say 8 sunny hours

thus the solar cell output needs to be 900 / 8 = 112.5 watts for 8 hours solid ( say 13V @ 8.7 amps )

To allow for inefficiencies in the system, provide for longer actual useable life of the system components, and the weather, it would pay to double these amounts, i.e. 12V 150 A-hr battery

and 2 x 150 watt solar panels. ( 13V @ 23 amps )

you're welcome ...
 

    mosfet123

    points: 2
    Helpful Answer Positive Rating

    Kripton2035

    points: 2
    Helpful Answer Positive Rating

mosfet123

Junior Member level 1
Joined
Oct 13, 2020
Messages
17
Helped
0
Reputation
0
Reaction score
1
Trophy points
3
Activity points
104
I see. Thanks. I will use with motion sensor to %50 load for 8 hours at nights and 4 hours it will run full load 25W (2-8-2) I have calculated its will spend 600W in 3 days so i would need 12,8 V 46Ah , if I multiply to 2 I would need 12,8V 92Ah
 

Easy peasy

Advanced Member level 5
Joined
Aug 15, 2015
Messages
2,672
Helped
955
Reputation
1,910
Reaction score
952
Trophy points
113
Location
Melbourne
Activity points
14,996
600 watt-hours over 3 days, not 600W. What is the average battery volts from full to flat, these are the volts to use in the calcs.
 

mosfet123

Junior Member level 1
Joined
Oct 13, 2020
Messages
17
Helped
0
Reputation
0
Reaction score
1
Trophy points
3
Activity points
104
Peak 14,6 , Undervoltage protection 10,8V , Undervoltage protection recovery 12V
 

Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top