Truly a hell of a lot better than guessing on LEDs. The less I care about mine the better. It doesn't seem to do well at all with my wireless USB/battery(18650) travel router connected via USB (12v->5v step down) and shows a 0w->3-6w->0w drain, value changing every few seconds. I don't really understand it, but if I leave the battery on my work bench not receiving any charge for several days it'll show say..20ah down, when reality is 50ah. I never noticed this in bench testing because I was discharging and then immediately recharging. Guess zero current calibration doesn't work well with whatever pulsing the router is doing. Means nothing when it recharges every day via solar though.Why is everyone so hung up on accurately tracking SOC? If a tenth of a percent, or even a few whole numbers off are gonna break your bank then your already pushing it too hard.. I honestly could care less if my BMV is accurate to a thousandth or not, I'm boondocking.. not running a laboratory.. I keep my LFP calibration off intentionally, I dont charge it to 100% SOC but I've got the gauge to reset/calibrate to 100% when its really about 94%.. my low SOC cut off takes this into consideration.. but for my purposes, its 100% charged at 14.4v and its fine.. I get the data I need, power in/out, along with historical comparisons, and a really good idea how much I got left or need to put in.
Coming from the good ole days of 4 separate LED's that read 20%/40%/80%/100% on the control panel I'd say what we got now days is far more than is needed to get the job done, and thats great..