Patent ID: 9018914
Filing Date: 2015-04-28
Classification: H02J

Abstract:
1. A system for monitoring a battery comprising: a battery pack having a positive terminal and a negative terminal; a communication bus coupled to communicate with an external device; a monitoring circuit coupled to the battery, the monitoring circuit monitors a first parameter of the battery, the monitoring circuit being further coupled to the communication bus and compares a communication signal received from the communication bus to a desired reference voltage; a first voltage level shifter coupled to the communication bus, the first voltage level shifter changes the reference voltage; a first N-type switching device having a control terminal and a first controllable impedance path and being coupled to the monitoring circuit, the first controllable impedance path of the first N-type switching device being coupled to a negative terminal of the battery; and a second N-type switching device having a control terminal and a second controllable impedance path and being coupled to the monitoring circuit, the second controllable impedance path of the second N-type switching device being coupled to the first controllable impedance path of the first N-type switching device and the negative terminal of the battery pack; wherein the communication bus remains communicatively coupled to the external device when the negative terminal of the battery pack is not electrically connected to the negative terminal of the battery.