Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: roycv on July 02, 2018, 10:52:55 AM

Title: Solar power
Post by: roycv on July 02, 2018, 10:52:55 AM
Hi all, has anyone any recommendations for small boat size solar cells?  I have just found in my junk box some old fresnel lens solar cells, they are not very large just 2" x 1 1/4" and there are 5 in series.  I measured the o/p on load and it was nearly 1 volt.

They just about spin a very low powered motor!  Even in this bright sunlight!  Any ideas or actual uses?  I am more interested in which and what solar cells can be used, I have some old tape drive motors that are very low power that might do.

regards Roy
Title: Re: Solar power
Post by: grendel on July 02, 2018, 12:38:53 PM
I removed the solar panel from a solar charge power bank, this will be used to power the LED lighting on the boat (using the remains of the power bank as the rest of the supply to create the battery to power this)
Title: Re: Solar power
Post by: tigertiger on July 02, 2018, 02:22:58 PM
With cells so small, I think that the low power motors running on 1 v might not have enough torque to turn a prop in water, not at a speed to drive a boat anyway.
Title: Re: Solar power
Post by: malcolmfrary on July 03, 2018, 09:38:52 AM
Apart from the type of technology involved with any particular type of solar cell, the amount of energy you get out depends on the energy going in, and that is governed by the surface area.  2.5 square inches will probably do next to nothing, 1 volt would not power anything worthwhile even if there was useful current there, which is doubtful.
If you can pile enough of them in series to get more volts, back-up battery charging becomes possible if they can have a very long charge time compared to a short run time.
There are examples of working boats using solar power, but they use quite large solar arrays for the size of boat.  for an ambitious example.