I'd say that anywhere between 42v and 46v is "normal" for a 36 volt lifepo4, 12cell pack.
Just depends on exactly what the designers set the bms and such for. I have noticed though, that after a year or more of daily use, charger output may drop a volt or more. So eventually you end up undercharging a bit compared to when it was new.
THE LIPO RULES. NEVER ABOVE 4.3V NEVER BELOW 2.7V DON'T PUNCTURE
Ideal charging /discharging range for Lipo, 3.65v minimum 4.1v maximum
See battery technology section, FAQ thread at the top of the page for lipo noob info.