As I said, simply VERIFY all other sensors/meters. Once you know the readings are accurate, you're good to go. If not, you can adjust for any discrepancies, or upgrade. Otherwise, you're going on possibly false info. And all things must agree with, or at least relate back to, what your batteries are telling you. Until such time, they are the master, and you are the slave. Role reversal is the ultimate goal, in this case.
Case in point, the Wattage display on my xantrex prowatt 1000 is off by 18 watts. And it only displays to 10, 100, and 1000w, (0.01, 0.1, 1.0 respectively) .At some point it rounds up or down. So I can turn on a 13w light and a 7w light, and the display will read 0.00w. Imagine trying to determine Ah usage based on those numbers. I solved that issue by buying a Mega Watt.
Likewise, its Voltage display is only good to 1/10th of a volt. And it tends to round up at about 0.015v. So, if the bank is at 12.22v, it will read 12.3v. That 0.08v difference represents 30Ah on my 430Ah bank, and potentially several amps of charging current when charging. I solved that issue by buying handheld volt and amp meters, and a Trimetric.
None of this is absolutely critical, or life threatening, but it's nice to know if you ever have to do some troubleshooting (or deal with an overly sensitive inverter).
