Post by papaof2 on Nov 15, 2021 5:21:42 GMT -6
I planned to do some "in the dark" maintenance - testing some older batteries that serve as small power points during extended power outages - and needed an appropriate load for a 30AH battery. There was a convenient Schumacher PID-760 760 Watt modified sine wave inverter and a clamp-on work light with a 15 watt bulb (15 watts for testing how long backup power lasts at low loads - long outages may need a little light or a little power for hours, such as the average power for the laptop I use for writing is about 12-13 watts, so a 15 watt bulb is a good test load). The inverter is perhaps 85% efficient, based on the label: 12 volts, 75 amps; 900 watts in for 760 watts out is about 85%.
I had a power supply connected thtough a solar charge controller (as if keeping the battery charged with a solar panel) and I discovered that the PID-760 inverter is a power waster, drawing 0.07 amp when it's connected but not turned on - the charge current increased that much when the PID-760 was connected - and that's a great deal more than the 2000 watt pure sine wave inverter on the solar power system draws when it's in the connected but OFF state. The PID-760's ON/OFF switch is multi-function, with a long press for ON or OFF and a short press to display battery voltage, output voltage and the watts of the load when it's ON. Either the electronics that handle the ON function use a huge amount of power (that can be done with a chip that uses microamps when idle) or the big filter capacitor in the inverter is showing its age. I didn't take time to disassemble the inverter for testing but now I know to not leave it connected when not in use. Just another little bit in getting the most run time from the backup power...
Walmart still has the PID-760 for about $65 but there are better choices. Mine was appreciably less than that with the "discount of the day" offer when I bought it.
I had a power supply connected thtough a solar charge controller (as if keeping the battery charged with a solar panel) and I discovered that the PID-760 inverter is a power waster, drawing 0.07 amp when it's connected but not turned on - the charge current increased that much when the PID-760 was connected - and that's a great deal more than the 2000 watt pure sine wave inverter on the solar power system draws when it's in the connected but OFF state. The PID-760's ON/OFF switch is multi-function, with a long press for ON or OFF and a short press to display battery voltage, output voltage and the watts of the load when it's ON. Either the electronics that handle the ON function use a huge amount of power (that can be done with a chip that uses microamps when idle) or the big filter capacitor in the inverter is showing its age. I didn't take time to disassemble the inverter for testing but now I know to not leave it connected when not in use. Just another little bit in getting the most run time from the backup power...
Walmart still has the PID-760 for about $65 but there are better choices. Mine was appreciably less than that with the "discount of the day" offer when I bought it.