Hello. I live in London, UK. I've dabbled and played with solar for about 12 years. To get started and find out what it was all about I originally bought a 60w thin-film solar panel kit from Maplin, which I put on the roof of my south facing car port, and attached it via its charge controller to two 88ah leisure batteries wired in parallel to give me what felt like a whopping 176ah. Once set up in my car port I then had no idea what to do with it, other than pop out and charge my phone and kindle occasionally! Which of course when it was raining or cold I didn't do. I bought the thin-film panels as they were supposed to work better in cloudy conditions which are quite prevalent here. At the time I didn't know that thin-film have a short life-span and sure enough about 8 years later they stopped producing power. So they then got replaced with a 100w mono-crystalline panel and a new, bigger, PWM controller. In this setup I actually wired it properly with fuses and DC dual-pole circuit breakers as I'd learned a bit more.
But I still didn't really know what I wanted to do with it, other than have it as a "just in case" off-grid system to charge phones and other USB powered stuff. I started to acquire some 12 volt appliances like a 12v TV and 12v fridge, and found myself eagerly checking the actual power input on devices and discovered that quite a lot are actually 12v with a 240v wall plug providing the ac/dc conversion. I also started to acquire a small number of small 12v deep cycle batteries (intended for golf buggies or mobility scooters) in the 12-50ah area to play with portable power (built a 50ah AGM portable/luggable solar generator for use in the car and camping) and powering Raspberry Pis to run things off-grid. To keep these charged up I gradually acquired a few 20 watt panels: these, it turned out, are exactly the right size to hang in the windows of my south-facing spare bedroom, connect in parallel and via another PWM controller charge all the batteries in turn, plus powering the charger for the various 18650 batteries used to power torches and fans This small bedroom system I use MUCH more than the bigger car port system on account of the fact it's indoors! I also use the 20 watt panels and controllers in my vehicles to keep the batteries topped up - this proved to be very useful during the pandemic as I didn't drive them anywhere.
One of the problems living in London is the urban foxes. They just LOVE wires. They have chewed through almost every wire I have ever installed outside (solar fountain, solar lights, solar you name it...all rendered useless). The car port solar panels were no exception. Despite running as much of the cable as possible through copper pipe (ha..bite that you swines!) they STILL found the little bit that is unprotected and chewed it. Several times. Usually I manage to notice in time and fix it before any permanent damage is done, though once I did have to bring the batteries back using the fabulous CTEK 10 amp charger. But I've been really busy at work over the last few months and appear to have spectacularly failed to notice the cable had been bitten again. No power getting to the batteries. When I checked last week, the batteries are both sitting at 4.5v. They ain't coming back from that! That said, they are also over 10 years old, albeit rarely used, so probably at the end of their life anyway.
I was ready to pull the trigger on two Trojan T105s as my received knowledge is that these are the standard off-grid go-to batteries, when I discovered this resource and Will's YouTube channel. I don't have a lot of money and LiFePO4 pre-built is just out of my price range. But now....I'm daring to think....self-build from China! 4s 280Ah works out roughly the same price-wise and ah-wise as the T105s...but you can use more of the LiFePO4s stored power, they charge quicker and have many more cycles. And while I'm at it, why not go 24v? And MPPT. So....am here to learn and absorb before rushing out and replacing, and in the meantime contemplate what it is I actually want now from the system rather than just a 10 year experiment to see what it can do.
Thank you for listening.
But I still didn't really know what I wanted to do with it, other than have it as a "just in case" off-grid system to charge phones and other USB powered stuff. I started to acquire some 12 volt appliances like a 12v TV and 12v fridge, and found myself eagerly checking the actual power input on devices and discovered that quite a lot are actually 12v with a 240v wall plug providing the ac/dc conversion. I also started to acquire a small number of small 12v deep cycle batteries (intended for golf buggies or mobility scooters) in the 12-50ah area to play with portable power (built a 50ah AGM portable/luggable solar generator for use in the car and camping) and powering Raspberry Pis to run things off-grid. To keep these charged up I gradually acquired a few 20 watt panels: these, it turned out, are exactly the right size to hang in the windows of my south-facing spare bedroom, connect in parallel and via another PWM controller charge all the batteries in turn, plus powering the charger for the various 18650 batteries used to power torches and fans This small bedroom system I use MUCH more than the bigger car port system on account of the fact it's indoors! I also use the 20 watt panels and controllers in my vehicles to keep the batteries topped up - this proved to be very useful during the pandemic as I didn't drive them anywhere.
One of the problems living in London is the urban foxes. They just LOVE wires. They have chewed through almost every wire I have ever installed outside (solar fountain, solar lights, solar you name it...all rendered useless). The car port solar panels were no exception. Despite running as much of the cable as possible through copper pipe (ha..bite that you swines!) they STILL found the little bit that is unprotected and chewed it. Several times. Usually I manage to notice in time and fix it before any permanent damage is done, though once I did have to bring the batteries back using the fabulous CTEK 10 amp charger. But I've been really busy at work over the last few months and appear to have spectacularly failed to notice the cable had been bitten again. No power getting to the batteries. When I checked last week, the batteries are both sitting at 4.5v. They ain't coming back from that! That said, they are also over 10 years old, albeit rarely used, so probably at the end of their life anyway.
I was ready to pull the trigger on two Trojan T105s as my received knowledge is that these are the standard off-grid go-to batteries, when I discovered this resource and Will's YouTube channel. I don't have a lot of money and LiFePO4 pre-built is just out of my price range. But now....I'm daring to think....self-build from China! 4s 280Ah works out roughly the same price-wise and ah-wise as the T105s...but you can use more of the LiFePO4s stored power, they charge quicker and have many more cycles. And while I'm at it, why not go 24v? And MPPT. So....am here to learn and absorb before rushing out and replacing, and in the meantime contemplate what it is I actually want now from the system rather than just a 10 year experiment to see what it can do.
Thank you for listening.
