Simple Lead Acid Battery Charger


Posted on Jun 7, 2012

The above pictured schematic diagram is just a standard constant current model with a added current limiter, consisting of Q1, R1, and R4. The moment too much current is flowing biases Q1 and drops the output voltage. The output voltage is: 1.2 x (P1+R2+R3)/R3 volt. Current limiting kicks in when the current is about 0.6/R1 amp. For a 6-volt battery which requires fast-charging, the charge voltage is 3 x 2.45 = 7.35 V. (3 cells at 2.45v per cell). So the total value for R2 + P1 is then about 585 ohm. For a 12 V battery the value for R2 + P1 is then about 1290 ohm.


Simple Lead Acid Battery Charger
Click here to download the full size of the above Circuit.

For this power supply to work efficiently, the input voltage has to be a minimum of 3V higher than the output voltage. P1 is a standard trimmer potentiometer of sufficient watt for your application. The LM317 must be cooled on a sufficient (large) coolrib. Q1 (BC140) can be replaced with a NTE128 or the older ECG128 (same company). Except as a charger, this circuit can also be used as a regular power supply.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

usb to rs232 converter using ft232
60W Amplifier
boost converter circuit for digital
Speaker Microphone circuit diagrams
AC Locomotive Auxiliary Equipment
usb switch schematic circuit
X and Y direction motor
5-channel low-power programmable sensor signal processor with AD7714 circuit
Hotel ultrasonic interference detection system based on ultrasonic probe DSP interference US0012
Vehicle lights at night rendezvous controlled circuit



Top