Electric vehicle battery charge indicator - has crossing indicator needles and Zener diode voltmeter circuit and ammeter

摘要

A unit to check the remaining available charge of a vehicle battery, allowing for the effect of ambient temperatures, is connected across a battery (1) and its load (Zu). A thermal ammeter (3) is connected to one terminal (B) of the battery and to a circuit (4) with a Zener diode (5) connected to the other terminal (A) and to a load resistor (R1) with a voltmeter (6) connected across it. The voltmeter an the ammeter are part of a crossed-pointers indicator which with graduations for the crossover point which indicates the battery charge available.