Rover: Added power limit page

common/source/docs/common-advanced-configuration.rst

@@ -86,6 +86,9 @@ tuning options for the vehicle.
 [site wiki="plane"]
     In-Flight FTT and filter control <common-imu-fft>
     Limiting Maximum Power Draw <batt-watt-max>
+[/site]
+[site wiki="rover"]
+    Limiting Maximum Power Draw <batt-watt-max>
 [/site]
     Limit Cycle Prevention <common-servo-limit-cycle-detection>
     LUA Scripting <common-lua-scripts>

rover/source/docs/batt-watt-max.rst

@@ -0,0 +1,20 @@
+.. _batt-watt-max:
+
+===================================
+Limiting Maximum Battery Power Draw
+===================================
+
+Sometimes power needs to be limited to prevent issues with battery sag or overheating. This can occur because of the use of lower C rated batteries, high power motors, high ambient temperatures, uncooled engines or ESCs, or other reasons. This topic discusses ways to limit the maximum power draw from batteries.
+
+Methods to Limit Maximum Power Draw
+===================================
+
+The first and simplest is to restrict :ref:`MOT_THR_MAX<MOT_THR_MAX>` to a lower value. This limits the maximum throttle controlled allowed. Unfortunately, this will not set an exact power limit and might require some trial and error to find the right setting.
+
+A better way is to use a power limiting parameters:
+
+- ``BAT_CURR_MAX``
+
+The ``BAT_CURR_MAX`` parameter can be used to limit the total amperage that can be drawn from the battery(s). If battery current exceeds this value then the system will reduce max throttle (:ref:`MOT_THR_MAX<MOT_THR_MAX>`) to lower the current draw. If current demand is reduced, the max throttle will slowly grow back to :ref:`MOT_THR_MAX<MOT_THR_MAX>`. Use 0 (default) to disable this feature.
+
+The ``BAT_CURR_TC`` parameter can be used to adjust the rate at which the max throttle is reduced when the battery current exceeds the ``BAT_CURR_MAX`` limit. This can help to fine-tune the response to high current situations and prevent sudden drops in throttle. Smaller values will result in a faster response, while larger values will provide a more gradual adjustment. The default value is 5.