Hi areza,
Could you post circuit here, as I'm looking for a desulfonator also and all the linksn on this thread are dead!
Could you post circuit here, as I'm looking for a desulfonator also and all the linksn on this thread are dead!
I've been using this kind of device in my car. Really can't tell whether it helps or not because matery life still varies depending more on brand than anything else.areza said:
Found this site about Pulsers/desulphators: http://www.courtiestown.co.uk/batteries/batterydesulfators/batterydesulfators.htm
Very interesting!!!!!!!!!
I've been using NICD instead of lead for lots of things because lead batteries are problematic, and it sucks if you happen to drain them too far. However, if lead batteries can be restored to a decent fraction of their capacity, it's worth it.
I surely want to try something like this with a TL494.
By the time I found the forum thread, all of the URLs are bad so I can't see schematics. I'll just come up with my own. EDIT!!! I found the desulfator.pdf - works nice, I want to make a TL494 version of that circuit.
Now Eva mentions putting a High Frequency AC into the battery, but what about just HF pulsed DC in the proper polarity? I've also considered 24-36V pulses as well, and using the pulse width to very the avg charge current.
I've been using NICD instead of lead for lots of things because lead batteries are problematic, and it sucks if you happen to drain them too far. However, if lead batteries can be restored to a decent fraction of their capacity, it's worth it.
I surely want to try something like this with a TL494.
By the time I found the forum thread, all of the URLs are bad so I can't see schematics. I'll just come up with my own. EDIT!!! I found the desulfator.pdf - works nice, I want to make a TL494 version of that circuit.
Now Eva mentions putting a High Frequency AC into the battery, but what about just HF pulsed DC in the proper polarity? I've also considered 24-36V pulses as well, and using the pulse width to very the avg charge current.
Batteries are not all that complicated. I know a guy that cuts batteries apart and cleans the crud (lead sulfate correct?) with a pressure washer and refills them and expoxy's them back together. The only real difference between the so called "long lasting" batteries and the cheaper counterparts is the distance between the plates. If they put the plates farter apart it takes longer for the sulfate to bridge the gap.
lead acid batteries are cheap and widely available compare to NICD, these are 180AH batteries , my proto is based on SG3524 with some added comparator and flip flop to control various voltage level and current for bulk and float charge state , the reason i pick PWM method over linear cos , they said to be produce less gas and heat and help desulfate batteries without equalise phase ,
STILL NOT SURE ABOUT SMOOTH DC PULSE OR PULSE DC WITH HF RINGING
STILL NOT SURE ABOUT SMOOTH DC PULSE OR PULSE DC WITH HF RINGING
How much of the original battery capacity is possible to retain? I am especially interested in current output as I need to restore the starter battery for my motorcycle which is a big twin that requires ~300A cranking current. With 200A@7V indicated by my current meter, the engine doesnt even turn over.
A new battery is 150$, and the old one only lasted a few years..
A new battery is 150$, and the old one only lasted a few years..
Guys, from what Eva says & the link I posted to - the correct (& only?) way to desulfonate a SLA battery is to use pulses which knock off the sulfate crystals back into solution in the elctrolyte - I think this needs a resonance around 3MHz.
last few days i have read some appnotes and research papers on pulse charger, some of them use smooth dc or block hf ringing cosh hf ringing would degrade battery life, on the other hand a desulphator sole purpose is to produce enough hf ringing to brake crystals,
correct me if i m wrong, so which one i should take, smooth dc pulse or ringing dc pulse,
correct me if i m wrong, so which one i should take, smooth dc pulse or ringing dc pulse,
I have recovered some batteries using a simple circuit with a light dimmer. The hot line of 120v AC is connected through the dimmer and a 0.22uF or so capacitor (up to 5uF for a car battery) to one terminal of the battery. The other terminal is connected to AC neutral. If needed, I sometimes add a high current bridge rectifier between the circuit and battery to make it a pulse charger.
BTW, out of three UPS batteries I tried to recover like that, I only managed to return one into a usable state. But it worked great for two car batteries I used it on.
BTW, out of three UPS batteries I tried to recover like that, I only managed to return one into a usable state. But it worked great for two car batteries I used it on.
This topic made me search a little over the web and i made some spice simulations over it .
My search confirmed what Eva said about the 3 Mhz .
(Although i must confess that i would have trusted on Eva's opinion to begin with)
Right now i didn't have the time to actualy build the simulation and try real life .
With the half a dozen accu's in a very bad shape here its a very intresting idea .
What i was thinking of also .
Wouldn't it be possible to measure the internal resistance while charging/desulfating .
My logic was those battery's have a very high internal resistance with succesfull desulfating the internal resistance should go down .
(My spice simulation was with pic processor to make the pulses for the mosfet)
In time (when i have time) i will try and build it to try in real world 🙂
@Areza
All chargers i seen based on 3842 or 3525 had the classical setup with output inductor .
Every charger has a ripple the conventional charger has no capacitors on the output and just puts 100 Hz dc on it .
How ever i must say that i didn't read any decent information about high frequency behaviour of accu's .
(I tryed to find it last year because i wanted to try charging with hf dc ).
I'll get back on this .
Good luck Walkura
My search confirmed what Eva said about the 3 Mhz .
(Although i must confess that i would have trusted on Eva's opinion to begin with)
Right now i didn't have the time to actualy build the simulation and try real life .
With the half a dozen accu's in a very bad shape here its a very intresting idea .
What i was thinking of also .
Wouldn't it be possible to measure the internal resistance while charging/desulfating .
My logic was those battery's have a very high internal resistance with succesfull desulfating the internal resistance should go down .
(My spice simulation was with pic processor to make the pulses for the mosfet)
In time (when i have time) i will try and build it to try in real world 🙂
@Areza
All chargers i seen based on 3842 or 3525 had the classical setup with output inductor .
Every charger has a ripple the conventional charger has no capacitors on the output and just puts 100 Hz dc on it .
How ever i must say that i didn't read any decent information about high frequency behaviour of accu's .
(I tryed to find it last year because i wanted to try charging with hf dc ).
I'll get back on this .
Good luck Walkura
star882 @ great idea, never thought this way before, hope to use it some time, thanks
walkura @ thanks for your time. i m also agreed with Eva, and get some idea as well. i would prefer measuring internal resistance manually with power resistor after removing surface charge with some heavy load.
is there any web link for those 3842/3525 based charger so i can have a close look.
walkura @ thanks for your time. i m also agreed with Eva, and get some idea as well. i would prefer measuring internal resistance manually with power resistor after removing surface charge with some heavy load.
is there any web link for those 3842/3525 based charger so i can have a close look.
The chargers i mentioned are in my workshop and (unfortunatly) i don't have schematics .
But i do have a datasheet with a switchmode charger .
http://focus.ti.com/lit/an/slua055/slua055.pdf
All the smps chargers i seen (in person) had an output inductor .
Although i did see a few datasheets where they didn't use them .
http://pdfserv.maxim-ic.com/en/an/AN680.pdf
http://focus.ti.com/lit/ds/symlink/bq24745.pdf
Today i was reading the website of a company we work with and they stated that dc ripple was reducing the life expectation of accu's
But this concerned a traction charger (+2 Kw)
http://www.axima.cz/eu/pdf/atypy_GB_4_HFBC_1.pdf
Hopefully i remember correct and you knew the power intergration charging datasheet .
Otherwise they have a application note aswell about a small switchmode charger .
By the way today i connected a battery to a (improvised) pulse generator .
(I connected a 65 Khz sg3525 with 27 volt dc pulses ,just 10 Ohm on the gates so it rings like big ben)
It will need some more time before i can say anything about the result .
But i'll let you know when i see any result .
See you later .
Walkura
But i do have a datasheet with a switchmode charger .
http://focus.ti.com/lit/an/slua055/slua055.pdf
All the smps chargers i seen (in person) had an output inductor .
Although i did see a few datasheets where they didn't use them .
http://pdfserv.maxim-ic.com/en/an/AN680.pdf
http://focus.ti.com/lit/ds/symlink/bq24745.pdf
Today i was reading the website of a company we work with and they stated that dc ripple was reducing the life expectation of accu's
But this concerned a traction charger (+2 Kw)
http://www.axima.cz/eu/pdf/atypy_GB_4_HFBC_1.pdf
Hopefully i remember correct and you knew the power intergration charging datasheet .
Otherwise they have a application note aswell about a small switchmode charger .
By the way today i connected a battery to a (improvised) pulse generator .
(I connected a 65 Khz sg3525 with 27 volt dc pulses ,just 10 Ohm on the gates so it rings like big ben)
It will need some more time before i can say anything about the result .
But i'll let you know when i see any result .
See you later .
Walkura
luka said:
It worked nice for my 10Ah/12V motorcycle battery, I built a simple flyback thing that I drove from a frequency generator with 4kHz pulses. After every pulse, the inductor unloads a current spike into the battery. I used this for ~10 days and the capacity given ~10A load went from 32 minutes to ~43 minutes measured until the voltage dropped below ~10.1V - the cold start capability of the battery also seem to have dramatically improved.
Good evening .
Sorry it took a little before i come back with my results .
I must confess that i had only a few days that i could have my setup run .
(there are to much deadlines to make)
But I clearly measured that the internal resistance of the battery slowly improved .
My setup was rather improvised .
I took a old pulse generator that was still laying around (SG3525) and connected it like a buck boost .
The gate resistors i made very small (10 Ohm) to induce ringing.
With a low dutycycle i adjusted the frequency till i saw it was ringing round 3,3 Mhz .
During the day there was a steady increase of the charging current and a slow but steady dropping in the internal resistance .
(those accu's are in a very ,very bad state)
The current that could flow was no more then 100 mA due to the internal resistance .
During the day it increased to about 300 mA ,for a 60 Ah battery still nothing but it was a clear measurable improvement .
(Do keep in mind that i intentionaly tested on accu's that are beyond any hope of recovery )
My selection criteria were ,easy measurable high Ri ,clear plastic housing so i could see the plates ,expandable in case of
After i seen the internal resistance drop for several workdays i decided that it will be worth to build some more trials ,but i didnt get further then a preliminary simulation & program .
On the web i found 1 schema of which i also made a simulation .
When i thought of what i read here and else where on this topic i'm not that sure on the usefullnes of the pulser based on the 555 .
The file desulfator in the rar file is still very basic (for simulation speed i tend to do it like that)
You can open it in Proteus & load the program into the pic by rightclicking on the processor and selecting the program .
In time (in the meaning of when i have time) i will add routines for measuring the internal resistance of the battery periodicly & a decent charging alogarythm .
(I want to combine it with a charger that holds a log of the battery being processed ,so i can monitor the progress during the testing fase)
Although i know its not much ,i hope its of use or brings you to idea's .
When i have some spare time i'll make some scopepics of the waveforms i measure.
But they are very close to what the simulation shows on the scope .
(you will have to set the scope in proteus to 2 or even 1 uS to see what i tryed to achieve)
Sorry for my bad spelling .
Have a nice eve Walkura.
Sorry it took a little before i come back with my results .
I must confess that i had only a few days that i could have my setup run .
(there are to much deadlines to make)
But I clearly measured that the internal resistance of the battery slowly improved .
My setup was rather improvised .
I took a old pulse generator that was still laying around (SG3525) and connected it like a buck boost .
The gate resistors i made very small (10 Ohm) to induce ringing.
With a low dutycycle i adjusted the frequency till i saw it was ringing round 3,3 Mhz .
During the day there was a steady increase of the charging current and a slow but steady dropping in the internal resistance .
(those accu's are in a very ,very bad state)
The current that could flow was no more then 100 mA due to the internal resistance .
During the day it increased to about 300 mA ,for a 60 Ah battery still nothing but it was a clear measurable improvement .
(Do keep in mind that i intentionaly tested on accu's that are beyond any hope of recovery )
My selection criteria were ,easy measurable high Ri ,clear plastic housing so i could see the plates ,expandable in case of
After i seen the internal resistance drop for several workdays i decided that it will be worth to build some more trials ,but i didnt get further then a preliminary simulation & program .
On the web i found 1 schema of which i also made a simulation .
When i thought of what i read here and else where on this topic i'm not that sure on the usefullnes of the pulser based on the 555 .
The file desulfator in the rar file is still very basic (for simulation speed i tend to do it like that)
You can open it in Proteus & load the program into the pic by rightclicking on the processor and selecting the program .
In time (in the meaning of when i have time) i will add routines for measuring the internal resistance of the battery periodicly & a decent charging alogarythm .
(I want to combine it with a charger that holds a log of the battery being processed ,so i can monitor the progress during the testing fase)
Although i know its not much ,i hope its of use or brings you to idea's .
When i have some spare time i'll make some scopepics of the waveforms i measure.
But they are very close to what the simulation shows on the scope .
(you will have to set the scope in proteus to 2 or even 1 uS to see what i tryed to achieve)
Sorry for my bad spelling .
Have a nice eve Walkura.
Battery desulphator circuit
I found this http://hmin.tripod.com/als/andysm/docs/Lin_Jao2.pdf that discusses the circuit from the Home Power magazine.
I'm too am looking for a battery desulphator circuit to build - just wondered if anyone has built this design and how successful it was or perhaps can comment on the circuit design.
Thanks
I found this http://hmin.tripod.com/als/andysm/docs/Lin_Jao2.pdf that discusses the circuit from the Home Power magazine.
I'm too am looking for a battery desulphator circuit to build - just wondered if anyone has built this design and how successful it was or perhaps can comment on the circuit design.
Thanks
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