Temperature Compensation--Battery or Ambient?
OK I have had my fill of why you need a temp comp probe to the battery casing or battery post (whichever one this week it is supposed to go on, the neg or the pos :) ) I understand temp comp and ag...
Forum Discussion
For common battery types;
The battery case has a large thermal mass related to the electrolyte and therefore the time constant related to the case temperature change is quite long.
The plates of the battery, terminals, have a much faster time constant related to the electrolyte and therefore give a faster response to the change in electrolyte temperature.
When the battery is cold, it needs to be over charged to receive a maximum SOC, plus the efficiency of the battery is reduced.
However, when the battery is hot, the charge needs to be reduced or damage to the point of failure can occur, plus the efficiency is reduced.
Most battery types are really designed for maximum efficiency to occur in a very narrow temperature operating range.
The temperature compensation is designed to maximize battery life while trying to reach a full SOC.
Ambient and plate temperature will never be the same unless the battery is sitting dormant for an extended period of time.
The battery case has a large thermal mass related to the electrolyte and therefore the time constant related to the case temperature change is quite long.
The plates of the battery, terminals, have a much faster time constant related to the electrolyte and therefore give a faster response to the change in electrolyte temperature.
When the battery is cold, it needs to be over charged to receive a maximum SOC, plus the efficiency of the battery is reduced.
However, when the battery is hot, the charge needs to be reduced or damage to the point of failure can occur, plus the efficiency is reduced.
Most battery types are really designed for maximum efficiency to occur in a very narrow temperature operating range.
The temperature compensation is designed to maximize battery life while trying to reach a full SOC.
Ambient and plate temperature will never be the same unless the battery is sitting dormant for an extended period of time.
