Battery high temperature threshold. If system battery temperature exceeds threshold
a battery high temperature alarm will occur.
Values are represented in thousandths of a degree.
Units are displayed in the scale shown in
the 'dm3StatusSysTempUnits' OID (Celsius or Fahrenheit).
Attempts to set the value above or below the acceptable range of the powerplant
will cause the value to be set at the high or low point of the range respectively.