Lead-acid battery charger

This circuit delivers an initial voltage of 2.5V per cell to rapidly charge a battery. The charging current decreases as the battery charges and when the current drops to 180 mA the charging circuit reduces the output voltage to 2.35 V per cell, leaving the battery in a fully charged state. This lower voltage prevents the battery from overcharching, which will shorten its life.

The LM301A compares the voltage drop across R1 with a 18 mV reference set by R2. The comparator’s output controls the voltage regulator, forcing it to produce the lower float voltage when the battery-charging current, passing through R1, drops bellow 180 mA.
Read the rest and view the Car battery charger circuit.



8 Responses to “Lead-acid battery charger”

1. henry says:

   August 17, 2008 at 4:39 pm

   Isa there no subst for LM301 used in the schematic diagram

   Reply
   • SINDHURA says:

     July 22, 2009 at 9:50 am

     is there any substitute for LM301

     Reply
   • Nisha says:

     November 5, 2009 at 3:19 pm

     yes n that is 555

     Reply
2. henry says:

   August 17, 2008 at 4:41 pm

   i want to know if there are other circuit that can be used instead of the above circuit. Please kindly send me a copy to practice.THANKS

   Reply
3. thulasiram says:

   April 3, 2009 at 12:28 pm

   i want know about the circuit of the charger,since iam an electrical engineer

   Reply
4. Max says:

   June 11, 2009 at 8:00 am

   i want a fast charger, the one i have cannot quickly charge 200Ah battery as power supply in my country is not regular. can your circuit be modified to charge at 10 -15 A?

   Reply
5. John says:

   August 20, 2010 at 3:37 am

   Thanks for this interesting charger Admin. I was not able to find the link to “Read the rest” as mentioned above.

   Kind regards.

   Reply
6. car battery charger says:

   August 21, 2011 at 1:13 pm

   Thanks for the great article, I will track it and perfect it.

   Reply