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Workshop Solar Charger



In order to provide workshop lighting and power prior to mains electricity being installed, this system was used in order to charge and maintain two leisure batteries for this purpose. One being dedicated to running workshop lighting and the other to provide basic power to run a radio or small computer.


The workshop


Initially the walls were lined with visqueen damp proof membrane and then an inner frame was constructed from 70mmx45mm timber (3"x2") and this was treated with an anti-fungal agent.


Next 50mm insulation board was cut to size and inserted into the ceiling and 25mm board was used for the walls. 

Finally, the walls and ceiling were clad with plywood, my 8-year-old son is used here for scale.


Panel placement


Initially I thought that the panel mounting positions were little limited, being fixed at about 240 degrees from north and set on an angle of 12 degrees.

However by doing some research it was found that below 12 degrees apparently panels will not self-clean but as the pitch of my workshop roof appears to be at about 12 I should be OK.

Also according to the table below (found by looking around on the net) the panels will collect about 90% of the available energy which I can quite happily live with.



Design - Solar panels and LED lights


Two 100w solar panels and three 10w warm white LED arrays where purchased for this project with the following specifications:





Design - Mounting System


A system of mounting was then devised that used lengths of stainless steel studding, angle iron and lengths of 25mm box aluminium.




Solar Panel Installation


Once this was installed it was then possible to move forward with the design and installation of the lighting and power system. These brackets had to be installed prior to the internal insulation and cladding mentioned above being installed.


The installed panels.


Design - Circuit


The two solar panels have been given independent 10A regulators/chargers to which leisure batteries are attached.

The output of PV#2 charges accumulator #2 and is intended for non lighting power via Bus #2.

PV#1 intended for lighting charges accumulator #1 which in turn powers bus #1. The power for Bus#1 can be switched to an internal 12V5A supply that can be used to supplement the solar charger supply during battery maintenance of periods of prolonged use.

This uses a simple latch in order to perform the switch between supplies, the external supply can be activated via the NO switch which in turn activates the latch. This is held on using the voltage originating from the 12V mains supply but again this can be interrupted by depressing the NC switch.

The advantage of this, is that should the mains supply fail the power holding the latch closed will also be lost causing the source for Bus #1 to drop back to battery supply.

Lamps and voltage indicators are also included on the design in order to show the operation state of the panel.



Panel - Construction


The circuit was then built up within a 300mm x 300mm enclosure.


inside view - the two charging regulators are the blue objects in the center of the panel.


Lighting and Power Point  


 As discussed above the two supplies provide lighting and power for the workshop.


Three car accessory type 12V outlets powered from bus #2.


Completed Workshop


The  solar charger is mounted on the wall in the far corner. The accumulators or leisure batteries are seated on a custom stand on the floor beneath this.