Hi, I have a Mppt 150/70 Mc4 and it has been working great for the last 4 years. I have the Bluetooth dongle so I can monitor the PV array out put and then the load.
But now something strange is going on.....
When the sun was setting I noticed the voltage didn't drop to below ~25v. Even when I disconnected the Pv array the voltage is the same. For some reason the Pv voltage is more or less set to the same voltage as the batteries (24v).
It's like the battery voltage is leaking out to the PV connectors. Not until I disconnected the batteries, the controller stopped "charging" (blue light on). And now when I connected the batteries back the voltage for the PV array is again ~24V. I checked with voltmeter that the voltage I was reading on the app was coming to the Pv connectors and it is.... Please help! Is it still safe to use? Is it broken? What can I do?
