The installation has been working great for around 4 years, then a few days back, it developed an odd fault. Nothing has changed. As the sun comes up the batteries are charged as expected, see graph (reading are from a GX/Grafana) until it gets to about 100W, the solar charger battery voltage reading then shoots up to 13.88v and the charger goes into float mode. The actual voltage reading via the BMV-700 is 12.8V.
Any ideas ?
