Monday, 18 June 2018

First name basis and the solar panels

Postman Wee has now made so many deliveries our relationship is on first name basis.  I think we might get an invitation to next year’s Chinese New Year.  Obviously we are securing his employment!

Today he delivered the solar panels I ordered for the trailer.  To my surprise they actually came in a bag, although the carry straps are too long.


When I opened the bag I immediately realised there was a potential problem.


There’s a strong aluminium handle and securing clips on one edge with hinges on the opposite edge.  That’s not the problem.  I don’t like the fact that the solar cellss and glass are on the outside surface where they are possibility going to be damaged.

On the inside are two adjustable legs, two connector boxes, a small solar controller and 5 metres of cable with an Anderson Plug.


The first thing I did was test the panels by placing them out on the lawn in the sun with the multimeter connected to the Anderson Plug to check the voltage.


The small solar controller is regulating the voltage to 20 Volts which is far too high for a 12V battery.  That’s not an issue because the trailer DC to DC charger also has an integral MPPT solar controller.  I can probably bypass the small panel controller.

The cap on the terminal box clips on.  Inside are pos and neg soldered terminals.  I used the soldering iron and disconnected the wires as part of my project to reverse the panel folding system.


The hinges were pot riveted to the frame and were easily removed by drilling off their heads.  This separated the panels allowing me to place them with the solar cells facing towards each other.

In the photo below you can see the original hinge holes at A.  I’ve marked out the new holes at B and drilled the middle hole.  The cable joining the two panels is at C and I’ve secured the cable with the last of my Sikaflex at D.


Then I realised I’d made a mistake erred in my judgement.  Can you see the problem?  When the panels open the connecting cable isn’t going to move freely through the two holes.  I may have to relocate them.

This next photo is a better demonstration of the problem.   The grey duct tape is holding down the cables whilst the Sikaflex sets.  Note I have shortened the 5 metre extension cable by cutting it and fitting an Anderson Plug.  I’ll fit a second Anderson Plug on the other cut end.


It was at this point work came to an unplanned end when I couldn’t find my pot riveting pliers.  After several hours of unsuccessful searching I gave up for the day.