Multiple cell battery voltage measurement

摘要

A method and apparatus to detect cell voltage of each of a plurality of battery cells in a rechargeable battery pack is disclosed. The method comprises generating a wave form with a positive phase and a negative phase by a current limited square wave generator. The wave form is a square wave having a maximum peak-to-peak voltage when the square wave generator is not loaded to be current limited. Then, sending the positive phase of the wave form to a first loop from a capacitor to the positive side of a battery cell. And, sending the negative phase of the wave form to a second loop from the negative side of the battery cell toward the capacitor. Finally, detecting a change of an electrical signal from the square wave generator. The voltage detection method and apparatus of this invention can be applied to detect whether a rechargeable battery cell has voltage lower than a low voltage limit or to measure the voltage of the battery cell in order to check its status.

主权项

1. A method for detecting a voltage of a rechargeable battery set, comprising the steps of:
generating a wave form with a positive phase and a negative phase by a current limited square wave generator that is capable of generating square waves having a maximum peak-to-peak voltage when it is not loaded to be current limited; sending the positive phase of the wave form to a first loop including a capacitor and the rechargeable battery set, the wave flowing from the capacitor to the positive side of the rechargeable battery set; sending the negative phase of the wave form to a second loop including the capacitor, the second loop connecting to the negative side of the battery set, the negative wave flowing from the negative side of the battery set toward the capacitor; and detecting a change of an electrical signal from the square wave generator.