battery charging indicator

I p battery charging indicator 41.141 Sealed 6 V or 12 V lead-acid batteries, under normal charging conditions, are charged at a constant voltage of 2.3 V per cell. The charging current reduces during the charging: when it reaches a value of 10 mA, the battery is deemed fully charged. To check this, you do not need an expensive ammeter. The present circuit uses an LED (light- emitting diode) to indicate when the battery is fully charged. The green indicator LED is connected in the collector circuit of a p-n-p tran- sistor. As soon as the transistor con- ducts, the LED lights. This happens when the voltage drop across resistor R1reaches the forward bias threshold of the base emitter junction (about 0.6 V). When this resistor has a value of 56 Q, a charging current of around =1N4001 (1 A) 1N5401 (3 A) 85433 10 mA, Ri is shunted by diode D1 which limits the voltage drop across the resistor to about 0.7 V. The maxi- mum charging current depends on the diode used and lies between 1 and...