I divided the power system into a starting battery and two service batteries with a voltage-sensitive relay. Two service batteries in parallel Yuassa 95Ah 12v are connected to Smart solar100/20 and two panels 24V 215W in series. I decided on a series after mounting and measuring with an open contact. Back then, in winter, 5-6 degrees on the Adriatic coast, the voltage was 80V.
Meanwhile, after heavy rains, although the connectors are located under the panel, I found them completely wet and the 25A fuse on the controller itself was blown. I removed the connectors and used the connectors and replaced the fuse on the controller. Still the controller doesn’t work.
I assume that the controller failure is the result of a short circuit due to rain. However now at a temperature of 20 degrees the voltage on the open contacts is 95V which is strange because experience has shown that panels give higher voltage in cold weather..
I will install a new Smart solar100/20 but I am unsure if it is safe to connect 215W 24V panels in series if I use the mentioned controller on a 12V system or should I connect the panels in parallel?