This is where I will be documenting my DIY journeys - gardening, off grid power and other projects.
It was the warm summer of 2018.
We had just bought our allotment with a green cottagge on it, completely off the grid - and that's where I saw it.
Facing us, from the top of the house was a wind mill!
The previous owner informed me that on the roof was a solar panel as well.
We had sustainable energy and it was amazing!
When the evenings came, we didn't have much power though - And I could not understand why!
So I went out and bought a multi-meter to measure the voltage of the old car battery, that was hooked up to the system - It was completely depleted.
The power we got during the days was just passing from the solar panels and the wind mill directly to whatever was using it (which was not much - a few led light strips and a pond pump).
So I had to do something about this seemingly fault of battery.
I didn't have a clue, how any of the systems were set up, so I started researching.
I learned that in order to store power in batteries without risk of destroying the batteries from over charge or over discharge, you need a charge regulator.
The charge regulator makes sure that once the battery is charged, no further power is put into it. And when it is empty, no further power is taken from it.
So I went online and bought a new charge controller from someone in China.
- They all had fancy specs and for a conspicuously low investment, I could get something great.
Well, it turns out, these specs are highly exagerated, and I was basicly buying exactly the same charge regulator as the one I already had.
Oh, and I still needed a new battery
Research led me to gel batteries - Apparently these had longer life, were designed for deep discharge and generally was what EVERYONE was using.
A swipe of the card and $300 later, I had bought a new battery.
It turns out, that not all batteries are created equally.
Car starter batteries are made for fast excercions of a large amounts of current to start engines - Not to run lights in a cabin and dish out power over prolonged periods.
These batteries generally start to degrade once you discharge them by a measly 30% of their rated capacity - And degrade fast once discharged to 50%
So the battery might have said 70Ah, but really, 21 Ah is the most anyone should take out of it (21Ah at 12V is the equivalent of about 250Wh). I'm pretty sure the previous owners of our cabin did NOT adhere to this principle.