Lead Acid batteries are supposed to be charged at a precise voltage and a maximum current, this equates to 2.35 volts per cell and a current of no more than 1/10 of the AH rating of the battery. Given we have a 6 cell battery rated at 12AH, we should charge at no more than 14.1 Volts and no more than 1.2 Amps. The Battery University is a wealth of information on this subject and with the technology being invented in 1859 by Gaston Planté, there is loads of information available on their characteristics. There are even cheap IC's that ensure the right charge conditions are met through the charging process.

Having spent many hours making the components and testing them in the house, its now time to put it all together and see what stops working as something is ALWAYS going to break or work in a fundamentally different way after installation compared to how it worked on the bench.

Well, it had to happen, its winter, its cold (obviously); the solar panel is in a fixed position and the sun is low in the sky, so we're just not getting the power or being able to store a sufficient amount to make this all work. The system will run for a couple of days, but then it dies in interesting and random ways, random lock-up's failures to open the door, etc. The batteries are just exhausted.

Any system needs a user interface and this one is no different. Also each system needs a name and whilst "Chicken House Controller" is descriptive, its hardly catchy either, so we need a name, but what to call it. Suggestions came and went, but nothing stuck, other than Domestic Management instructing that the coop is to be known as "Brkingham Palace", since its palatial compared to its predecessor, but that's for the house, not the control system.

The user interface module that's fitted above the main door allows you to see at a glance whats going on and to override the system or instruct it to unlock or lock the various doors.

The Rotator has arrived from America and duly gets powered up, tested and taken to pieces, its effectively a small 18VAC motor, a set of gears and a sturdy metal box.