Just doing a spot of experimenting with the currently reliable weather here in Galera. What you see here is a cheap 10 amp solar regulator which has 3 pairs of wires – one goes to the solar panel, another goes to the battery – the third pair go to the “load”.
The “load” in this case is a little 12v-5v convertor sitting on top of the battery – I plan to hook that to my Raspberry Pi at some point… but then over on the right is a standard 8-battery charger. I realised when looking at the instruction that it’s power supply was a 12v job – and that the unit could handle anywhere from 11v to 14v input – in other words absolutely ideal for powering from a lead-acid battery such as a car battery or alarm battery (the latter is what you see here).
The solar panel shown on the left here is way too small to be a great deal of use – it is able to put out about 400ma which means it will take maybe 16 hours to fully charge that 7aH alarm battery – I have a MUCH bigger panel but that will have to wait for our July trip in the car as I could not fit it into the case. That has a 3 amp output which will charge the little battery in under 3 hours and is better suited to charging a car battery.
The regulator is great, I now have two of these – cheap as chips from Ebay – will allow a maximum 10 amps load and protects the battery from overcharging and over-discharge (simple lead acid batteries do NOT like being fully discharged and rarely recover from this unless they are what are called “deep discharge” types.
So with the setup above I’m happily charging my little AA and AAA batteries FOC from the sun – soon I’ll find a more practical application for this. I’ve a larger setup on the Pergola and that’s powering a bright hanging lamp without any issue.
While that is going on I have my soil moisture sensor under test.. that’s producing an analog out put which I’m hoping to use to provide sensible watering for Maureen’s plants shortly. The sensor will indirectly control an (already fitted and tested over a year) cheap washing machine valve which controls the cold water feed to the plants.
Just as well as she picked up a boatload of new plants from the garden centre yesterday.
All good fun.