DROK Digital Multimeter DC 8-100V 20A Voltage Amperage Power Energy Meter, DC Volt Amp Tester Gauge Monitor LCD Digital Display with Built-in Shunt

This device works perfectly on my test bench to replace the need for pulling out my hand-held multimeter. The wiring is very straightforward and outlined well on the back cover. There is also enough blank space inside to safely attach small brackets to the body for mounting as seen in my pic. My other pic shows the device properly reflecting the milliamp draw of an auto accessory that was previously tested with matching results.

I have numerous Drok power products and they are reliable and well designed. At this point I add their name to a search and hope they supply what I need. I added this meter to my Renogy solar controller to measure load. The backlight is very sharp and the readings accurate. I don't think you can go wrong with it.Get a PDF of the manual while you wait for it to arrive.How you can go wrong HiHi. If you connect from solar panel to charge controller, this and other meters may not start up properly. This may be due to very low current at start up and ramping up the voltage.You may need some circuitry to work around this problem. Try connecting the plus lead on the meter to battery rather than the solar panel positive output.

UPDATE:After about a month of solar panel monitoring I decided to upgrade my wiring setup to monitor the output side of my charge controller instead of the line from the solar panel. When I went to remove this from the circuit, I was surprised to see the accumulated energy field read 238 Wh when it last read 1058 Wh. It should have stayed in 4 digit Wh range or at most switched to kWh readings. There's no way my 15w panel could have generated the 9,998-odd kWh necessary to roll the display.Mine also isn't showing the right voltage anymore. A 12V DC supply applied to the line side reads about 19V yet the output side reads 12V with a multimeter. When new, the display was very accurate.I still like this meter, but obviously something is wrong with mine.This is a pretty slick tool -- my review is probably closer to 4.5 stars, excellent but not quite perfect. The screen is very easy to read even in outside daylight and it draws very little power -- my 15w solar panel will light this up with a no-load indicated voltage of 13w under fluorescent lighting. For me the killer feature is the energy (watt hours) figure and the fact that it has memory and will retain this value even when it loses power, which is important for my use of monitoring the net energy production of my solar panels.My only complaints are pretty small -- the wiring terminals are kind of tiny, and while they accept the 16ga wiring my 15w panel uses the little flat head screws are tough to screw down securely. A molex type socket would be a lot more secure. The only other thing I wish was a "factory" option is a pre-fit project box for this. I bought one that's a pretty good fit, but had to do my own cutout in the lid and tap and seal my line and load holes.I plan to use this between a solar panel and a charge controller to determine how much charging my panel actually accomplishes. It's a 15W nominal panel and in theory even at a daily average of 5W I figure I should be getting around 50Wh worst case out of it. For a panel that sits out in direct sun, I *should* be adding 250Wh or 20Ah to my 12v battery for the 5 days it sits unused yet last summer the battery stopped holding a charge completely. This monitor will clear up whether the battery just gets overused or whether the panel isn't supplying meaningful power. I notice this vendor also sells battery monitors and I may add one of those plus another one of these on the load side of my battery to figure out what my power drain is; I may just be using more power than my alternator plus solar panel can put back in.If the vendor ever gets into more complex products, this would be an awesome thing to add networking to for remote monitoring.

These things are the bees knees. I’ve modified all of my battery chargers on several diesel generators to charge through these. These are standby gensets and starting on the first try is critical. Previously it was hard to tell exactly how healthy the batteries were without a load test or hydrometer reading. Those things are still important, but now we can tell at a glance how the battery is, and especially how many watt-hours the battery has consumed. If the volts are low (on a constant-voltage / current-limited trickle charger) or the watt-hours charged are excessive, you know the battery needs closer inspection.Good value and recommended.

Works great, tested against another meter and readings are extremely close. Great addition to my 290w 36v solar panels. Mine shuts down around 5.9v, but it remembers the cumulative energy.UPDATE: After 4 months, it started reading wildly high voltages, current was still correct. Finally I contacted DROK, and they wrote me a helpful email within 24 hours. Bonus points for them for being responsive and knowledgeable. The 20A version can be recalibrated. The difficult parts are soldering a switch to the internal contacts on the board and finding a 20.0v 1A power supply and 20 ohm 20w resistor. I did, and it calibrated within about 5 seconds.Dear customer,If it is possible, would you please try to calibrate it with following method.1. Turn off the power supply.2. Connecting power supply (20V/1A) and load.3. Short connect two calibrating spots (Open the back cover, you can find two holes which marked by “W” on the edge of board)4. Turn on the power supply.5. When the screen display changed from “CAL---“ into” ---PASS”, that means the calibration is finished.Any more questions, please let us know.Best regards,DROK

The meter works as advertised and for the price it has excellent value. Note that the current meter is in the negative side between DC IN - and Load -. This is important if you use a switch, like I do, to change the meter's polarity between charging and discharging a battery. The current meter will not run backwards. In other words, the meter will only increase its reading when positive current flows in the direction of DC IN + to Load +. Current will flow in the other direction, but the power and current meters will not read negative values, and the Watt-hour meter will not decrease its reading.To use the meter to monitor power from a solar panel to a battery, I connect the solar panel to the DC IN + and DC IN - terminals, and the battery itself to the Load + and Load - terminals. When discharging the battery into the intended load, I reconnect the meter (using a switch) into its conventional connection topology. Since the current meter is in the negative side, DC IN + and Load + are connected together in the unit. In other words, they are the same node.The unit is made to mount in a square hole in 0.032" thick material. I used a thin bead of Silicone adhesive around the bezel to strengthen this mechanical connection.The operation of the screw terminals can be confusing, and can lead to damage if one is not careful. They come tightened down, so to connect a wire first loosen the terminal by turning the screw counterclockwise several turns, insert the wire in the gap that's just been opened, and then tighten the screw in a clockwise direction. I verified that the terminal block will accept 12 gauge wire.

Awesome product easy setup and wire. Printed a case perfect fit.

Using this on a battery charger and it's very accurate!Note, that it needs to see about 6.5 volts D.C. on the input or it won't turn on!Remembers Energy usage even when shut off/no voltage coming in!

Wanted to get a power meter to figure out how much power my tent trailer used on a typical trip. we are taking a 3-week off-grid trip this summer and needed to know if solar can charge the batteries or if we need a generator.Originally was just going to hook up in the circuit temporarily and take some measurements, but once i hooked it up it seems like really valuable info to have all the time. I installed the meter in the cupboard below the galley on my tent trailer and tapped into the wire coming from the batteries back to the inverter.Seems to work great so far, only been installed a few days, but so nice to have accurate information about how much energy my tent trailer uses!

PROs: Good price. Works great. I love the on/off back-light display. Very accurate numbers (matches very close to my high quality multimeter).I use it on a 12VDC battery/solar powered iPod charger/stereo external speaker amplifier system (camping). The unit itself consumes 0.8mA @12VDC with back-light off and 2.8mA @12VDC with back-light on. I have an external switch so I can monitor solar power in OR load power out.Cons: Only con is that the current unit resolution is too large. The 0-20A minimum current that it reads is 10mA (10,20,30 etc). I would have liked it to have 1mA range, or better yet Selectable: 0-19.999A range with 1mA resolution and a 0-1.9999A range with 0.1mA resolution. (Power and W.Hr to scale by 10 also).

Worked great for about six months, very accurate. Very easy, you use until I blew it up. Doesn't like too much voltage.

Good quality meter for a good price.Works very well when I connected it to my E bike charger.

These work great, show very accurate information. The backlight is even and bright, easily visible at night. Voltage, current, power, and energy are very useful information and are accurate.