my third tempbug: http://www.instructables.com/id/TempBug-internet-connected-thermometer/?ALLSTEPS likely to be used for testing
This is DIY solar panel and battery voltage tracker located in Lappeenranta, Finland.
Monitoring of a solar installation with two 24V 400W panels in series (morning), four 24V 330W panels in series/parallel (afternoon), one Tracer4210AN MPPT controller, one Must PV 1800 Hybrid Inverter and four 6V 600Ah battery in series
Monitoring of a solar installation with 12V 50W panel and 12V 100W panel in parallel, Tracer1210AN MPPT controller, 3S10P 33Ah 18650 battery