I just dove into advanced configs for the first time on my BMV & MPPT.
I'm in the US so I had the app settings set to a temp unit of F.
I tried setting the MPPT temp compensation but got really confused and I think its because of a bug in the software (& a weird manufacturer spec)
To start off, this is the manufacturer spec (Exide):
So from that...on my 12v (6 cell) batteries, I believe this is my math:
-0.063 V/Cell / 10*C (18*F) = -63mV/Cell /10*C (18*F)
-63mV/Cell /10*C (18*F) = -6.3mV/Cell /*C (1.8*F)
-6.3mV/Cell /*C = -37.8mV/*C
First question...is that right? Do I need to enter -37.8mV/*C based off how they wrote the spec?
Secondly...the bug...
In the custom preset, although my units are set to *F, and displaying mV/*F when I look at the preset, it is asking for mV/*C in the prompt. When I try to enter -37.8mV/*C into a custom preset prompt, it will only let me enter up to -30.0. When I then view the entry on the preset display, it is much higher..-50something.. I forget exactly.
So I did the math again in *F thinking maybe the app is off on its units:
-63mV/Cell/18*F = -3.5mV/Cell/*F
-3.5mV/Cell/*F = -21mV/*F
When I enter -21.0mV/*F into the prompt asking for mV/*C, it saves the value because its under (er, over) -30. Then I go back to the display view and it is displaying -37.8mV/*F...not what I entered but a familiar number because that is the value I tried to get before in mV/*C
So I think the app has its units crossed here...when the app is set to *F, I believe the temp compensation display is actually showing *C, but labeled *F and the prompt is actually asking for *F but displaying *C. The units are both the opposite of what they are displaying.
For now, I have entered -21 and it is displaying -37.8..which I think is what I want, but reads very different from what I'd expect to see.
Does that sound right?
