When do you see zero for MxC?
I have only seen that once or twice, but I don't have any hills where I'm at in Minnesota, so I hardly ever exceed 53-54% SOC these days.

When cold ( 15-25'F ) my MxC is mid-twenties and slowly climbs as the battery warms up. MxD is usually 20 higher ( do we assume amps? ).

So when cold ( 25'F ) MxC = 25.0 and MxD = 45.0.
When cool ( 45'F ) MxC = 35.0 and MxD = 55.0.
When mild ( 65'F ) MxC = 45.0 and MxD = 65.0.

I have never seen MxC over 45.0.
I don't think I've seen MxD over 69.0.

Maybe the scale and/or offset is not correct.
When the pack is 65'F and I slam the brake, I get 70A ( a ~1375 reading on the SG for current ) and I think 1445 = zero.

-John