其它暂且不说,但该信号并不是电池报警,
以下内容见840D_FB1.PDF

DB10D.BX109.6 Air temperature alarm

The ambient temperature or fan monitoring function has responded. This could be due to the following:
 The temperature monitoring has registered ambient temperatures that are too high(approx. 60 oC). Alarm 2110 “NCK temperature alarm” is triggered. The speed monitoring of the 24 V DC fan used to cool the module has responded.
Alarm 2120 “NCK fan alarm” is triggered.
Measures: Replace the fan and/or provide for additional ventilation.
When a temperature or fan error responds, a relay contact (terminal 5.1, 5.2 or 5.1, 5.3) in the infeed/regenerative feedback unit is activated which can be evaluated by the customer.