Review on Smart 4-in-1 DC Electricity Usage Monitor: LCD Display, 6.5-100V Voltage, 0-100A Current, Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt by Derrick Patterson

This is a high quality meter that relies heavily on the accuracy of the current shunt. For the 50 amp version the current was 12.63 amps (see figure) when the 4.5 digit ammeter read 12.98 amps. If that accuracy is enough then this is a great meter at a good price. The problem was related to the current shunt not being properly cut. In fact, it turned out that the shunt had not been severed at all. I also have a 100 amp version of this meter and it measures current with much better accuracy. I recommend people to buy the 100 amp version even if they only need 50 amps. The 100 amp version measured 12.87 amps for an identical circuit. Nothing is perfect, but this measurement is much more accurate than 12.63 amps (remember the correct value is 12.98 amps). The numbers are easy to read and the backlight is excellent (but can be turned off if desired).