Automatic Lead acid battery charger – This is a very simple and effective circuit for charging the batteries.
with a low-cost project, you can control the charging of the 12v battery.
The circuit mainly composed of 555 timer ic.
The timer IC that cut off the relay and stop charging when the battery charge is full. and again the relay gets activated when the charge below 12v dc.
ie, the circuits will protect your battery from overcharging.
working
The circuit compares the input dc voltage and battery voltage, then the battery voltage is below 12v the circuits get opens and start charging.
if the charge above 13.8v ( adjust the 10k pot) turn off the relay and cut the charging process.
How the Lead acid battery get charged
As we know, to charger battery we need to provide a voltage greater than the terminal voltage in the battery. so to charge 12.5-volt battery we need to apply 13 volt
But what actually happens when we charge a lead acid battery?
it’s very simple to know. Well, some chemical reactions happen specifically, when the battery is connected with the charger the sulfuric acid molecules break into two ions positive ions 2H+ and negative ions so4 -.
The hydrogen exchanges electrons with the cathode and become hydrogen H.
This hydrogen reacts with the pbso4. In cathode and form sulphuric acid and lead. on the other hand so4 – exchange electrons with the anode and become radical SO4 -.
This SO4 react with pbso4 of the anode and create pbo2 and sulfuric acid H2so4. the energy gets stored by increasing the gravity of sulphuric acid and increasing the cell potential voltage. The chemical reaction takes place at anode and cathode during the charging process.
Things are good enough for charging charging disconnects at 13.8 volt but then again when voltage comes to 13.7 it recharges but iam using it for 12 volt 40 ah battery so it’s ok
It works.
Nice pcb and schematics.
Realy easy design.
Thank you
thanks
1)in the diagram there are 2 led’s ,and at the end of the video you come up with 3 led’s; presume there is one in the emitterline of BC548???full charge?
2) how to best adjust the trimpot?
Pl call nomar