Hi
In an old thread https://forum.allaboutcircuits.com/threads/lead-acid-battery-desulfator.36174/ Sgt.Wookie mentioned

I'm using an N-channel version of Alistair's original design; it has a trickle charge circuit, peak voltage and average voltage test points added.

I would like to request Sgt. Wookie, if he wouldn't mind sharing the schematic of his version.

 

He hasn't been seen on this forum since Sept 18th, so you may have to wait awhile for an answer.

 

Plenty of working designed ones here .....


https://poemsrom.co/diy-battery-desulfator-schematic/

 

Plenty of working designed ones here .....


https://poemsrom.co/diy-battery-desulfator-schematic/

Thanks for your input.

Yes, I have seen most of them.
What attracted me in Sgt.Wookie's design was "trickle charge circuit, peak voltage and average voltage test points".

 

Which circuit diagram are you using, most desulphaters use a pulsed frequency of 1.5Khz to 22Khz.

 

Which circuit diagram are you using, most desulphaters use a pulsed frequency of 1.5Khz to 22Khz.

I intend to use this one.

 

Hello,

Did you also look at this thread:
Battery desulphation for lead-acid types - anyone? (Revisited)

Bertus

 

Thanks Bertus for the link.

I came across this circuit http://www.thompdale.com/battery_charger/desulfator/desulfator.htm
which provides a sequence of steps as described therein

"The planned cycle has four steps.
The first step is to pulse the battery for 15 seconds using a Charged-Induced-Pulse described by desufonator2.
The second step is a settling period of 1 second.
Third is a 100 microsecond pulse that shorts the battery (180 amps?) to remove dendrites.
And finally, a 5 second period to measure the battery voltage."

I am considering to build a circuit around Arduino, based on this idea replacing the battery voltage measurement circuit with battery internal resistance measurement circuit below:



I would like to have some valued, expert comments on:

a) the desulphator circuit (the one shown in the link with LTSpice schematic) which has 4 inductors unlike others which have 2 or 1 inductors.
b) the duration of each step (first 3 steps).
c) shortening of battery terminals

 

I am about to start my project but, I stuck at the first instant.

Since, most of the desulphator circuits are 555 based and the driving frequency is 1000-10000 kHz; I am little confused over what frequency shud I use to drive the mosfet. Would 5% ON time for N-channel mosfet be okay to start with?

Will the mosfet get warm under normal operation, I mean if everything is in order i.e. the frequency, the ON time, the inductor turns etc ?

 

Build the circuit shown , and modify it accordingly, there are plenty on youtube that are near enough all the same 555 circuit fully working,. The mosfet is on for 33mS, off for 750mS, 1273 Hz.

Here is one from Elektor 311 book, fully operational.

 

Thanks for the schematic. I have already studied this and many other 555 based desulfators, mostly variants of Alastair Couper's design. As mentioned above I am using Arduino to drive the mosfet and other sections.

I repeat my question, will the mosfet get warm under normal operation? It will help me to diagnose if the frequency and mosfet ON time are suitable for the mosfet.

Next, as requested in post #8, I intend to include 3 additional steps as mentioned in this link
http://www.thompdale.com/battery_charger/desulfator/desulfator.htm

I am bit concerned about the step in which the battery terminals are shortened for 100ms. I would like to have some comments on it.

 

I would like to have some tips on INDICATION or reading which can tell that the battery has been de-sulphated. There are some circuits which require to measure voltage in milli-volts using external voltmeter but I prefer something which can be displayed on LCD or indication with LEDs.