While car camping this weekend with my 100 watt solar panel, Victron connect 75/10 MPPT, and running a small 12 volt fridge, I had my first dead car battery.
My car would not crank and the fridge stopped running, but Victron Connect was showing a battery voltage of about 13.1 volts. I ended up jump starting the car. I suspected that the voltage display on the Victron was just wrong, since I had two devices that were both displaying low voltage symptoms.
When I got home, I disconnected the battery wires on the MPPT. At this point, the MPPT was only connected to the solar panel. Yet Victron Connect still reported a battery voltage (somewhere around 12.9 if I recall). How/why would the Victron report a battery voltage if I was not connected to a battery?
I suspect my dead battery was caused by the Victron constantly giving a false reading on the battery voltage, thus the Victron was probably not attempting to charge the battery.
Edited to add the following:
A couple weeks ago, I disconnected the battery from the MPPT without disconnecting the solar panel from the MPPT. Then, I reconnected the battery. However, I know I should have disconnected solar power, reconnected battery, and then reconnected solar. Perhaps connecting the solar panel/ battery in the wrong order caused the MPPT to get confused about the battery voltage?
So, last night, I disconnected everything and reonnected it in the proper order (battery then solar). Then, I used a mulitmeter to measure battery voltage and compared that reading to the Victron reading. The readings matched, and continued to match this morning. I plan on testing all this in my driveway (with benefit of multimeter if needed) to try to figure this out before the next camping trip.
Any tips on why I had the false battery readings would be appreciated!
