Tee hee, never mind the battery and the hydrometer, just fiddle with the Trimetric until it says what you want. :)
BTW, the Trimetric reads high on its rounding off to one decimal point on voltage, so that 13.7 is maybe 13.65.
Also, on your amps setting for how far down the amps get by the time you are "full." Our rig has a standing minimum amps draw of 0.3a except when the fridge cycles on at another 0.5a for 0.8a standing amount then. So if I decided that my low amps setting for "full" would be 1 amp, that would be when the charger is doing 1.3a or maybe 1.8 I guess.
All too confusing for me. It works fine without ever setting those "three things." It still does the accumulated AH, volts, and amps. (that is the NET amps in and out showing remember, not just your charging amps)