GoWISE Power 600W Pure Sine Wave Inverter 12V DC to 120V AC with 2 AC Outlets + 1 5V USB Port and 2 Clamp Cables (1200W Peak) PS1001
I bought this 600W unit with the intention to run AC loads in the RV, and for small tools in the field where 120VAC power is not readily available.
Out of The Box:
The unit comes with cables and clips; could be a little bit thicker, but ok, they get warm with use. The unit stays cool to the touch, there is a soft start button, and the power ramps up slowly. No voltage 117VAC RMS, and does not vary much with application of load. The remote is handy, and allows you to turn off the unit. On power is about 0.3A, while in standby off is less than 0.02A, so very good.
Plugged in a 600W rice cooker. Inverter worked liked a champ, did not complain once. The unit got warm after a while, and the fan ran a bit. AC Voltage stayed steady around 116VAC RMS. The unit only beeped alarm when
Plugging in a 1200W toaster to test the surge capability, it held voltage steady for about 1 second before turning off, so the surge power as advertised.
Computers, laptops, battery chargers worked great, all worked normally and did not complain.
This is where this inverter fails miserably. Plugging in a small fridge (160w), it took several tries for the unit to start the compressor. Normally with compressors, the starting wattage is 5-7 times that of the running watts, but the 1200w surge should take care of that. When tested on a small jigsaw (4amp) and bench grinder (2.5amps), the tools had a hard time starting up, and a buzzing noise from the inverter. Putting my meter across the inverter outlet, shown was voltage spikes of 190VAC when attempting to start and stop these tools. This means the inverter output circuitry is clearly lacking reverse EMF filtering such as chokes, flyback diodes, etc., or even a proper feed back to compensate for the power factor with inductive motor loads. Dangerous. Could destroy other devices plugged into inverter due to overvoltage. So even with a power factor of 60%, a 300w motor running would still be within the specs of this 600w inverter, and yet able to run it. So either the unit is defective, or a design issue.
I tried contacting GoWise US for tech support. The operator put me to their voicemail, left message, no response after 2 days, called again, this time they wanted to email me a form to fill out, but email never arrived. Poor customer service IMO.
If you are powering computer equipment, heating devices like coffee makers, then this unit works superb. For inductive loads, even if they have a wattage rating much smaller than 600W, this inverter has a hard time running them. And if it does run them, there is a strange voltage feedback into the inverter.
Get a MSW inverter instead since computers and heaters aren't bothered about pure sine wave.