I have studied many battery sulfator curcuit diagrams. What I concluded is that they provide a high voltage, high frequency (resonent) and low duty cycle pulses to the battery to break down the sulfate deposits. I guess the complexity in these circuits is that they use the power of battery which is under test. Am I right till? Ok now what if I I build a 1KHz oscilator with low duty cycle (about 10% and with all adjustable parameters) and send this frequency to a ferrite core step-up transformer through a power FET. I can use an additional power source instead of battery under test. (Please see attachment for block diagram). Will it start desulfating the battery? If it is ok then what should be the ratio of transformer. I mean what peak voltage should be at O/P ? Please help me in this regard. Thanks.

 

With flyback topology, I afraid the current rise aren't fast enough...

 

Hello,

When you do a search in this forum, there are some threads that might interest you:
Battery desulphation for lead-acid types - anyone? (Revisited)
Lead acid battery desulfator..
Battery desulphation for lead-acid types - anyone?

Bertus

 

...I guess the complexity in these circuits is that they use the power of battery which is under test. Am I right till? .

You cannot use a battery to supply power to that same battery to do this. To desulphinate a battery you basically overcharge it some, and you cannot get that charging current from that same battery.

 

You cannot use a battery to supply power to that same battery to do this. To desulphinate a battery you basically overcharge it some, and you cannot get that charging current from that same battery.

Thanks for your reply but almost all desulfators are doing this. They use the power from the same battery. Actually they increase the charging pulses through inductors to kick back the pulse to the battery. They never use any other power source but they always use a single battery.(Please see the attachment for a sample) Thanks.

 

With flyback topology, I afraid the current rise aren't fast enough...

Actually I want to take some openions thats why I posted this thread. Can you explain the reasons about why the pulse current would not raise enough? In SMPS, hundrads watts of power is delivered on the chopper output. Same thing is going to be here.

 

Thanks for your reply but almost all desulfators are doing this. They use the power from the same battery. Actually they increase the charging pulses through inductors to kick back the pulse to the battery. They never use any other power source but they always use a single battery.(Please see the attachment for a sample) Thanks.

Agreed. In fact all desulfurators I have seen require the battery to be charged.

 

I think the most common solution is to have a battery charger in parallel with the battery desulfater

 

Actually I want to take some openions thats why I posted this thread. Can you explain the reasons about why the pulse current would not raise enough? In SMPS, hundrads watts of power is delivered on the chopper output. Same thing is going to be here.

In SMPS, I believe we want the output to be as smooth as possible, hence the rise time doesn't need to be fast (in my opinion).

Unless if you're designing a SMPS that could deliver like 15V at 50A just to brute-force charge the battery, then, go ahead.
Just be careful, hydrogen accumulation is not a good thing and I've been accidently ignite a small battery; it explode and hurts my hand...


The rise time was governed by the inductance, more inductance means slower current rise time.

It depends on your desulphator design, it could be resistive, inductive, or capacitive.

All of the explanation below is based on my experiment and experience, not backed by any scientific means.

In resistive design, what I've done is take a capacitor bank of 24V (to minimize ESR effect), pulsed it to 12V battery with a MOSFET, it must be drived carefully, to avoid it heats up.
Spike of high current could be seen on the scope, the duty cycle is adjusted arbitrarily. The internal impedance of the battery itself is what limiting the current here.

In inductive design, I charged it up just before saturation, then release all the energy into the battery, sort of like a boost converter. This is the easiest way to get high-current pulse (to me at that time).

In capacitive design, I charged up a 10uF capacitor to ~400V, then discharge it via a SCR, just like CDI system. This is by far the highest current that I could generate, causing my switching element to breakdown easier.


All of the designs above have its own pros and cons, choose your own flavour, which is easier to build at present time.

Now I'm leaning towards to design a charger that could charge the battery before it reaches gassing threshold. It maybe utilise high current to penetrate the insulative layer, but short enough to prevent gassing, yet fast enough to to make practical.

Every person have their own favourite trick to use...

 

Let me keep it Too Simple

Take some water, heat it up, put as much Epsom salt(MgSO4) as it can dissolve, put it bit by bit in ever cell of the battery, Shake it, Recharge it for twice the usual time and use it as you would usually do.