12V Lead Acid Battery Desulphator

Lead acid batteries
often fail prematurely due to over-charging, under-charging, deep
discharging and low electrolyte level. All of these can lead to
sulphation of the plates which leads to high internal resistance and
eventual failure. Normally, this process is regarded as irreversible but
this circuit is claimed to reverse the process by applying high voltage
pulses to break down the lead sulphate compounds. The circuit is
essentially a high-voltage pulse generator which is powered directly
from the battery in question. If the battery is badly sulphated, it will
be necessary to connect it to a low power charger as well, say 2A. We
have strong doubts about whether battery sulphation can be effectively
reversed but we are publishing this circuit because the subject is of
particular interest.

Circuit diagram:

12V Lead Acid Battery Desulphator Circuit

12V Lead Acid Battery Desulphator Circuit Diagram

This circuit has been submitted to us from a number of sources so we
do not know who is the original designer. More information can be found
at http://shaka.com/~kalepa/desulf.
The 555 timer is connected as an astable oscillator with its output
frequency set by R1, R2 and C2. Its output pulses drive the gate of
Mosfet Q1 which turns on to charge inductors L1 and L2. At the end of
each pulse, Q1 turns off and the inductors develop a high-voltage
high-current pulse which is applied across the battery via fast recovery
diode D1 and the 100µF capacitor. The 555 is protected from the high
voltage pulses via its isolated supply, by virtue of the 15V zener diode
ZD1, the 47µF capacitor and the 330Oresistor R3.

Author: Silicon Chip – Copyright: Silicon Chip Electronics Magazine

Comments are closed.