Using panel that is smaller than required

System
System Posts: 2,511 admin
in General Solar Power Topics #1
Hi,

I posted here earlier asking about solar panel sizing, and after some helpful replies I calculated that I would need a 5W panel to meet my requirements. However, I am having a hard time finding any reliable 5W panels.
My question is, just in case I really cannot find a 5W panel, what would happen if I used a smaller panel (as a last resort), say one with 0.15A max current ?

My requirements,

Max current consumption = 1051.1 mA
Total AH = 0.969 AH
Panel size = 0.265 Amps
It is a small solar tracker project.

Logic tells me that it would just take longer to fully charge the battery , maybe for 1 day usage it would require 2 days charging ? Or would it not work altogether ?
As I've said, this is just a learning experience for me so I do not need the panel to have many days of storage, etc.

Thanks again.

Regards
Melvin
· Share on Twitter

Comments

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #2
    Re: Using panel that is smaller than required

    ICP make some 5 w panels (amorphous?). ~ 5w 350 ma. they are sold here in Canada by Canadian Tire.

    Eric
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #3
    Re: Using panel that is smaller than required

    Melvin,

    I believe you are in Malaysia... So, your best bet would probably to try EBay or the equivalent for used panels. VW when shipping their cars overseas puts a small solar panel in each one to keep the battery charged during shipment/storage (5-10 watts?). They seem to be around $10-$20 USD a piece in the US.

    Or, if you can find some solar powered yard lights (either in the store or junk yard)--you can use them. There are some solar powered security lights (used to be with filament bulbs, new styles now with LEDs) that have a nice panel with them too--might be cheaper than trying to buy a panel by its self (but you may not get a 12 volt panel...).

    Yes, you can use any size panel you want and charge the battery at home once every few days--The smaller the panel, the fewer number of days between recharging. And the longer the battery remains discharged (and the deeper the discharge), the less life the battery will have.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • System2
    System2 Posts: 6,290 admin
    #4
    Re: Using panel that is smaller than required

    Yes, I am from Malaysia. Unfortunately, most of the ones on eBay do not ship here or charge very high for shipping, around $30-40 USD... Canadian Tire does not ship here as well I think.

    Do you guys know of any other places to look for used panels ? Or any reliable manufacturers from the US or UK which ship worldwide.

    Currently I have two choices, a Solarex 6V 0.15A 1.2W panel and another unbranded 12V 5W one. The unbranded one looks kinda shady though and I wouldn't be surprised if it outputs way below its rated current ...


    Melvin
    · Share on Twitter
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #5
    Re: Using panel that is smaller than required

    it seems to me with the high number of japanese and chinese pv manufacturers that you should be able to obtain something from them. why go around the world when your neighbors have them? being in the usa i couldn't help you with a good link to an overseas dealer. hopefully, somebody else is aware of one or do a search from your location. contact those manufacturers too as they usually know reputable dealers.
    · Share on Twitter
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #6
    Re: Using panel that is smaller than required

    yes cheap ebay prices but exhorbitant shipping costs.... that seems to be the way it is... I have got several items out of Hong Kong at about $13 US items cost pennies (relatively)


    good luck in your search

    Eric
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
    · Share on Twitter
  • System2
    System2 Posts: 6,290 admin
    #7
    Re: Using panel that is smaller than required

    OK guys thanks for the input.
    · Share on Twitter

Categories