Buy ???? Pack Of 5 Three-Wire Calibratable DC 0~30V Blue Digital Mini Voltmeter Gauge Tester Mount Car Motorcycle Battery Monitor Volt Voltage Meter 0.36″ Blue LED Display Panel ????

8 reviews for Buy ???? Pack Of 5 Three-Wire Calibratable DC 0~30V Blue Digital Mini Voltmeter Gauge Tester Mount Car Motorcycle Battery Monitor Volt Voltage Meter 0.36″ Blue LED Display Panel ????

1. 

   Rated 5 out of 5

   Ken Simmons – October 22, 2018

   I purchased these units “on a whim” because they looked like interesting things for “experimenters”.First off, they come with ZERO “DOCUMENTATION”! With that typed, here is what you need to know.1. They’re good to 30 VDC MAXIMUM.2. They WILL NOT read “negative” input voltages!3. The RED wire is for DC supply voltage (3-30 VDC)4. The BLACK wire is the COMMON RETURN5. The WHITE wire is the MEASUREMENT wire (0-30 VDC input)Connect the RED AND WHITE wires to your “supply”, and BLACK to “ground/return”. If the voltage is GREATER than 3 VDC (30 VDC MAXIMUM!), the meter will “self-monitor” the DC voltage. If you connect the RED and BLACK wires to a separate source (i.e., 9V battery), use the WHITE wire as a “voltage probe” (0-30 VDC input, NO “negative” polarity!) and the BLACK wire as the “ground reference”, like a DMM. You’ll have 3-digit accuracy in your readings and the units will “auto-range”, moving the decimal point appropriately.Finally, I strongly suggest you “calibrate” these units using a Precision Voltage Reference (i.e., KKMoon – see my review on it!). Power the module using a 9V battery (RED and BLACK wires), and connect the Voltage Reference between the WHITE and BLACK wires. Chances are you’ll have to ADJUST the unit via the VERY SMALL potentiometer on the back (use a 2mm blade screwdriver) – BE PATIENT as a small “tweak” can “greatly” vary the display!Once you “calibrate” the units, they can easily be integrated into “low-voltage” circuits as monitors. BY THE WAY: the BLUE 7-segment displays are REALLY BRIGHT – you may want to get some blue-tinted plexiglas to make “display windows” for them. I hesitate to think how bright the other available colors are…

2. 

   Rated 4 out of 5

   Fito – March 16, 2021

   The media could not be loaded.  I love these displays, they work pretty decently for the money. I do a lot of research with cells, and I like to have an idea of its voltage all the time.Note: if you really need to measure low voltages, lets say, below 3 volts, you will need an external power supply or battery to feed each display. Which makes sense because if you are testing a dead (zero volt) battery with these displays, you won’t see any data. for voltages over 3 volt they work as intended.One thing to notice is I had to calibrate one of the packs. I compared the readings with my digital multimeter and it was a little bit lower than the real thing. The rest of them were perfectly fine.In my experience, I can recommend these displays, and most likely I will be buying more in the future.

3. 

   Rated 4 out of 5

   Amazon Customer – October 17, 2021

   all work fine. no adjustments needed2 batch of 10 pcs. 5 in original box the other 5 pcs were repackaged in plastic 1 bad.15 total 1 bad. other then that all been under constant power and working

4. 

   Rated 4 out of 5

   snortonj-Sturgis – May 1, 2022

   I just was hoping for a $2.40 credit, but that’s too simple, the “policy ” requires that the item be picked up. I’m not wasting somebody’s time with that……The other 4 are good.

5. 

   Rated 5 out of 5

   Brian Effword – August 14, 2022

   Perfect!!

6. 

   Rated 5 out of 5

   Mark M. Fiorentino – September 4, 2022

   One defective led dvm

7. 

   Rated 5 out of 5

   Larry S – November 10, 2022

   These are great little devices. I build various size battery packs and use these to determine their state of charge. The wide voltage range of 0-30v is perfect for my application They are very easy to use. If you don’t need to measure < 3v than the simple two wire connection is all you need. It doesn't get much easier than that. Even in daylight the blue display is bright and easy to read. All 5 of the voltmeters I received measure accurately and identical. Good quality. Highly recommend.

8. 

   Rated 4 out of 5

   Dave – November 20, 2022

   I have added some of these to some of my old supplies that have no readout.Just gives me a little more comfort knowing the voltage is ok.