I decided to have a go at a small scale solar power system to power my amateur radios and also some lights in my small radio shack.
After quite a lot of research I decided to order the parts and get it going. It was hard to decide which charge controller to use because I had read some horror stories about noise coming from them, and as this was for my ratio equipment this was a really important factor.
I started off with one 100 watt panel and a 30 amp PWM charge controller. This was about the lowest cost entry level parts I could get. My plan was to grow the system as and when I need to. I already had a 35 Ah deep cycle SLA battery which I charged from the grid as and when needed based on my estimated usage.
The latest update and about as much as I need is three 100 watt panels. I built a wood frame for them and when the weather eventually drys up I will paint the wood to match the deck rails.
The charge controller:
This is the 30 amp charge controller which allows the user to set various charge and load values. The full details which I wont repeat here are detailed in the online user manual. I power my HF Amateur Radio transceiver directly from the battery to minimize voltage drop between the radio and the power source. I use the optional load output on the charge controller to power the lower current devices like my 12 volt LED lights. I could have done these direct to the battery too but I decided to make use of the power measuring metrics which the controller provides. The wiring used is all 10 AWG and I use Anderson Power Poles on everything to make life easy to swap things around.
I started this system with my existing 35 Ah deep cycle battery, but since then it has been replaced with a new 100Ah SLA deep cycle battery. In the two pictures below the first is the 35Ah battery and the second is the replacement battery show as installed in the corner of my shack. I didn’t want to add expense replacing the battery until I proved out the solar power system would work for me, and as its worked out well I decided to upgrade the battery. I’ve left the two pictures here for reference.
I upgraded the battery and also added a small four digit LED volt meter to the solar panel input on the charge controller. This allows me to monitor the voltage the panel is supplying to the controller. Its a “nice to have” feature so I can see what the panels are supplying to the charge controller. My charge controller is set to 13.8v for the cut-off voltage and when the battery is charged to that level the solar panel is disconnected and no charging takes place (float charging up to 14.1 volts as and when needed). When its float charging the panel “off-load” voltage shows about 18-21 volts, even on a dull and wet day. If I find that I am using more power than the charger\panel can supply to the battery I will add another panel in parallel to the existing three to speed up the charging time. That’s a future upgrade only if I start to use more than I generate in a day.
The charge controller and the solar panel came from WindyNation. The quality of the components is really good.
See their website for more details:
The small battery came from Batteries Plus, but they don’t sell this exact model any more. The upgraded battery is a “Mighty Max” brand battery, I bought it through Amazon.com.
If your planing a solar power system on a small scale like I have here, and once you decide what capacity the battery needs to be, as long as you get deep cycle batteries of some sort that’s the main thing. Ordinary wet or dry lead acid batteries like car batteries don’t fair well to discharging and in the long term will cost you more money if your load causes a significant amount of discharge. There are however some loads which would be OK with a non-deep cycle battery, but my article is based on what I used for my system.
There are plenty articles on the web explaining how to calculate panel and battery requirements so I wont repeat that info here again.
Anderson Power Pole connectors:
You can source these from various places. I’ve got them from Amazon.com and also DXEngineering.com
If you like this post or have any questions that I can help with then I’d like to hear from you. I wrote this little article for my own reference and also in the hope that it can be of use to anyone that was interested in setting up an off-the-grid small solar power station.