Powering a radio with solar cells

[8bit]

I have a very small radio that takes two AAA batteries and runs on a total of 3volts. I would like to add a solar cell to it so I can run it without batteries. I am just a little confused as how to connect it to the power connecters at the back. The back of the radio is shown below.

 

[davenn]

hi ya

the negative from the panel goes to the spiral terminal on the lower left
the positive from the panel goes to the terminal that cant be seen just above the lower left terminal

NOTE you will need a panel that can produce around 4 - 4.5V as it will drop to around 3V when under load

MOST panels voltage rating is an open circuit voltage rating. Confirm the O.C. voltage before you buy the panel


Dave

 

[8bit]

Ah, thank you for clearing that up. I have a 3v solar cell and just no matter how I wired it I could not get any power in the radio.

 

[davenn]

Ah, thank you for clearing that up. I have a 3v solar cell and just no matter how I wired it I could not get any power in the radio.

is that 3V open circuit ?

measure the voltage with the radio as a load once wired to the radio correctly
you may find the voltage is dropping to 2V or less ( you may need 2 cells in series)

Dave

 

[Colin Mitchell]

A single solar cell is 0.5v

 

[8bit]

is that 3V open circuit ?

measure the voltage with the radio as a load once wired to the radio correctly
you may find the voltage is dropping to 2V or less ( you may need 2 cells in series)

Dave

That's the voltage across just the solar panel on it's own.

 

[davenn]

OK then it will drop substantially when a load is applied maybe as low as 1V, so you may need 2 or 3 in series

 

[8bit]

I have got hold of a Mini 4V 50mA solar cell and tested the voltage acrossed it while in the Sun. It was pushing nearly 4.5 volts(??) I attached it to the radio briefly but got nothing out of it(??)

 

[8bit]

OK then it will drop substantially when a load is applied maybe as low as 1V, so you may need 2 or 3 in series

Thanks Dave, I'll try and pick up a couple more. Thanks for the information.