Review on ⚡ Beleeb Battery Charger 12V 24V Smart Pulse Maintainer 12V/20A(max) 24V/10A(max) Repair Charger with LCD Display – AGM SLA Car Golf Cart Mower RV ATV, Portable Auto-Volt Detection 2Ah-200Ah by Scott Ramu

See attached drawings. What do "NI" and "TU" mean? I've been charging SLA 8Ah, 12V GEL after full charge, cable goes to battery, reading 0.143A and 14.21V from my meters for a long time, why does the amp never reset or stop charging and go to float? Also, your meter readings are far off and always show higher than my meters, for example: my meter shows 14.18V/17.8A, your display shows 14.8V/20.0A. Charges at 12.6V Li - Ion doesn't turn my lithium battery on unless I flip the switch to AGM/Gel so the output is higher, then immediately switch back to the 12.6V Li-ion position back to charge my lithium battery and also the highest max output current at 7.8 amps is not 20 amps like I expected from Li-ion ?