Can't set proper battery alarms

[Srelliks]

Using INav 9 with Matek F450 and Radiomaster Tx15 with Lua display widget script installed. flying with a 8,000 mah 4s set up, I've put the battery in configuration as a 6,000 mah with alert at 20%, but fuel gauge display gets to alarm level after less than 800mah used (battery is good and voltage is still at 16v) and I get verbal alarms.

Is this a problem with the Lua script on the Tx15 or some other set up issue?

Any suggestions?

[ja51d]

this isn't the lua script, it's almost certainly your current sensor calibration on the FC. the lua widget just shows whatever inav sends it.

the fuel gauge / capacity % alarm runs off consumed mah from the current meter, not voltage. with capacity set to 6000 and the warning at 20% it should only go off around 4800mah used. it's firing at under 800, and your pack is still at 16v (so barely touched) - that means inav thinks way more current has been pulled than reality. classic sign the current meter scale is off.

fix: configurator -> power & battery, watch the "mah drawn" value and compare it to what you actually used. if it climbs way too fast, bump the current meter scale (and offset) until consumed mah roughly matches real usage. on the F450/matek the default scale won't always match your actual sensor so it usually needs tuning.

side note since you mentioned 8000mah pack set as 6000 - might as well set the real 8000 so the % is meaningful, but that won't fix the over-counting, the scale is the real issue.

[Srelliks]

Thanks, the amps and the mah are reading correctly. If I put in a 6,000 mah battery and then set 20%, it should alarm after 4800 mah has been used, but I get the alarms after 800 mah (shown on the TX screen and OSD), if I keep increasing the battery size I can get a longer flight, but I shouldn't have too. I put the recommended meter scale for the Matek F405 (150) and did a check of the telemetry current against an inline meter (which reads amps, volts, watts and mah)