[Ham-Computers] Re: Ham-Computers Digest, Vol 43, Issue 15

[va3hsc at hotmail.com]

    E                         E= volts
-------          -------------------------
I       R           I=amps      R=resistance


     P                P=power/watts
--------         -------------------
E         I          E=volts   I=amps

    E x I   =     P
13.8 x 8  = 110.4

    P    /    E  =  I
110.4 / 13.8 = 8

    P    /  I  =   E
110.4 /  8  = 13.8

110.4 watts an hour

60 minutes in an hour divided by your 20 minutes
60 / 20 = 3

110.4 / 3 = 36.8 watts
You need 36.8 watts of power for 20 minutes

10 percent loss of power storing into batteries
6   percent loss of power in wires, controller, ETC.

36.8 + 16 percent = 42.688 watts of solar on a sunny day with the
sun a 90 degrees to the panel for one hour.

My self I would times it by three 42.688 x 3 = 128.064 watt solar
panel.



> Message-ID: <001701c7e86b$df3e5f60$8666f504 at ELNkk7rc>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Why should it be so hard for me to find a webpage that will tell me how
> large a solar panel I need to run a system drawing 8 Amperes at 13.8 VDC 
> for
> 15 to 20 minutes per day???
>
> Any suggestions?
>
> Thanks,
>
> Kurt