150A RC Watt Meter, High Precision Power Analyzer, DC 0-60V

Worked great to check amp draw on my r/c motor.

1) Works fine and seems accurate, voltage and power (= voltage*current) independently checked and it agrees to < 1%. 2) Display brightness is a bit of a sore point for me, but it’s still usable. I’m using it on a e-bike, and in sunshine or even relatively bright shade, I can’t see the display while riding; is ok in heavier shade or heavy cloud weather, and that’s tolerable for me. 3) This things lists itself as 150A capable, and as others point out, that’s ridiculous considering the wiring is #12 (20A usual rating) or maybe #10 (30A). However, for my usage case of 15A max, it’s fine. 4) power draw of this thing by itself: at 53V, I measured 37 mA, thats about 2 watts, snd implied R of ~1400 Ohms. Don’t know how current draw scales with voltage. To be clear, i’m using the input power itself to power this meter, not an external battery connected to the 3 pins on side. Note that the total energy used display resets to zero when the input voltage/power is removed, but that’s fine in my usage case.

I have read some complaints about the word provided being too short. They are about 3” long and we’re more than enough for me to splice into my system. Works well and has a very visible readout. Agreed with my handheld meter so I’m happy.

After 4 months of use, the unit just stopped working, for no apparent reason. Nothing changed in my system and I hadn't touched it in a long time. What is worse, is that when it failed it caused my charge controller to malfunction and over-heat to the point it was too hot to touch. The wires leading out from the controller to my battery bank were also very hot (I measured them at 120* F). I am assuming that there was a short of some kind in this meter that was causing the controller to malfunction. All my wires and connectors are to code and the overall voltage and amperage of my system are within the stated operating range of this unit and my other components. If I had not been at home when this failed, it could have potentially started a fire. Once I changed this unit out for a different model, the controller and wire temperatures are back to normal. I highly recommend a "shunt" type DC meter instead of this type of design. With a shunt, only a small amount of current passes through the meter, making these much safer. With this unit, 100% of the current flowing from the solar panels to the controller passes through this meter, not a safe design IMO.

I saw this meter on some YouTube solar system videos and ordered one. I like it so far and plan to get a few more to monitor my solar panel output.

Works OK. Does not work in reverse. So if you accidentally plug it in backwards, current will flow through it but it will show 0 amps.

I bought one of these a couple of weeks ago and it was DOA. Sent it back and Amazon gave me a refund. It would not light up or even give the source voltage. I bought the exact same meter and it works perfectly. Voltage is exactly what my voltmeter reads and depending on what power level I need it reads the wattage perfectly. There is always the possibility of getting a dud in anything. Glad I gave this device a second chance.

I built this into a harness to a LiFePO4 battery. The meter leads were 2 inches long and hard to connect up. It would be nice to have a switch on the power side as the meter stays on all the time.