Hey everyone! I recently built my own solar panels, and I'm facing some challenges. My latest panel is rated at 300 Watts, but I'm having trouble measuring the Amps. I'm using two Victron charge controllers (75-10 and 100-20) along with two 12V LiPO4 batteries (50Ah and 320Ah). My voltage levels are great, but I'm not getting enough wattage through the 75-10 controller, and I worry that I'm pushing too much into the 100-20, which is only supposed to handle 145 Watts at 12V. All the commercially available solar panels are rated much higher, like 300W and 400W. If anyone has successfully used Victron with their solar panels, I'd really appreciate your input!
3 Answers
Just a couple of thoughts: solar panels are very sensitive to their connections. If you don't have bypass diodes, even one underperforming cell can affect the entire panel's output. Also, if your batteries aren’t discharged enough, you won’t really see them charging at their full rate. Running a good load on the batteries during tests helps to confirm you’re getting the maximum output out of your charge controllers.
You might want to double-check if your DIY panels are actually performing to their claimed rating. Sometimes a missed link can mean you’re only utilizing part of the cells, which would cut your expected output significantly. Are you seeing any connection issues?
Wow, you built your own panels? That’s impressive! Just a heads up, sometimes the battery being full can limit the output from your Victron controllers. Are your charge controllers the SmartSolar models? If they are, you could use the VictronConnect app to get direct readouts, so you wouldn't even need an ammeter. I have a 75/15 controller with a 200W flexible panel, and I’ve only seen about 50-70W most of the time. Also, I’ve got a 100/20 controller with two 335W panels in series, which gives me around 3kWh daily right now. When it cools down after being sunny, I’ve peeped peaks up to about 750W, but that drops back quickly. What output are you actually measuring from your panels? If they’re 300W, what’s the expected voltage and what are you getting in real life?
I base the wattage on the specs from the data sheets. According to my listings, five panels from one set are supposed to produce almost 20 Watts, and I’m estimating around 40 Watts from another set. I have those two connected to my 75-10, but VictronConnect is only showing 8 Watts coming through. I've been adjusting them every twelve minutes to catch the sun.
I really need to figure out how to measure amperage. I’ve made sure nothing is exposed; all soldered joints were dipped in wax for protection.