DROKDigital Multimeter, DC 8-100V 100A Battery Monitor 12V 24V 36V 48V 60V Volt Amp Watt Meter, Big Color Screen LCD Display Capacity Time Power Voltmeter Ampmeter for RV Solar Panel Battery Charge

In simple terms, this works by adding up current going both directions. The meter itself uses almost no power and will not affect how long your system runs on battery.The instructions can be somewhat confusing if you don't have a good grasp of how circuits work. The wiring diagram - how you physically connect it - is very clear though.Here's an example of a basic config:I have 2x 12v AGM batteries, each 150 Ah, connected in series for 24v. My inverter cuts out at 10.6v.BAT = 150 - this is the battery raw capacity in Amp-hours.BPC = 40 - I chose 40% since discharging much below that shortens battery life. For Lithium you could set much higher like 80 - 95%.STI = 0.3 - if current is less than 0.3 amps either in or out, the display shuts off to save a bit of power.LVP = 23.5 - this tells the unit that the batteries are essentially 'dead' at this voltage. I chose 23.5v because that's about 40% capacity when under moderate load (C/10).LBR = On. - This causes the display to 'flash' (actually it's more like pulsing) if capacity is lower than 20%, OR voltage is lower than LVP, OR your batteries are charging.PAI = 0.06 - This setting is key to making sure the system does not drift. I found 0.06 amps works for me. Basically this means that any tiny errors in current measurement get reset to zero.All the other settings are not as critical and can be left as-is for most uses.I found that voltage measurements are accurate, and current measurement with the included shut is also accurate. I've used this in several actual power outages, and it works flawlessly.It comes with 2 connector cords, one short and one long, to fit your installation. The clear cover is nice too, keeps the dust out.

Great unit, easy install, and versitile.

At first this meter seemed daunting to install but in actual practice it is rather easy to install and get working. I do like the fact that it displays both output and input charge and estimates remaining battery time based on output rate. Very nice meter.

I got this shunt/coulometer to help monitor my new 250 Ah LiFePo4 battery for my small off-grid cabin. It seems to work okay, but there were no instructions in the box. I used the Amazon product listing, and YouTube videos to help set it up. It seems to be working fine. I figured out how to set the battery capacity, by trial and error.I think this is what I know...• The big green circle with the percentage inside: The life/charge left in the battery.• The tilted hourglass symbol: No idea!• The floppy disk icon with a number: No idea!• The large blue number followed by AH: the amp-hours of life remaining in the battery.• The 6-digit, time-stamp looking number: No Idea! (maybe hours, minutes, seconds left in battery at current load?)• Bottom Row:• First number: load/charge in amps. Negative means charging, positive means load going out.• Second number: Voltage of the battery.• Third number: Watts being used from the battery.I mainly got this to protect the battery and let me know how much charge is left. The color display is nice and looks more professional than the basic battery monitor displays. I also figured out how to lower the brightness of the screen, but would like to be able to turn it off when not in use, so it doesn't waste any battery power, but I think it is very minimal anyway. The solar panels can maintain this with ease.I also have no idea what the UIPC image is on the left.So, while writing this I tried one more internet search and found a manual. It is not a very good manual, but I think this is the right one.https://m.media-amazon.com/images/I/91iEI2GqGHL.pdfHope this helps. It is a good shunt and monitor. Both seem well built. Solid brass shunt with heavy duty bolts and connectors. I would have given it 5 starts if it came with a really good manual. I would get it again, now that I have a manual.

Working great. A must have.

DROK Digital Multimeter is a good buy and very handy to monitor you battery use. easy to install