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Lead-acid battery charger

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taz128

New Member
Hello, I would like to know if anybody can help me with a circuit to build a battery conditioner for 12v. The battery conditioner does charge the battery for 5 minutes and discharge it for another 5 minutes.
Thank you very much,
Taz128
 

MikeMl

Well-Known Member
Most Helpful Member
The battery conditioner does charge the battery for 5 minutes and discharge it for another 5 minutes.
All that will do is wear the battery out prematurely. Please cite a reference that shows that cycling a lead-acid battery does anything but wear it out.
 

taz128

New Member
All that will do is wear the battery out prematurely. Please cite a reference that shows that cycling a lead-acid battery does anything but wear it out.
Corry for my explanation.
First, it can recondition a used battery by sending small, resonate electronic pulses through the battery to break down moderate levels of lead sulfuric crystals. This not only cleans the plates but returns the "escaped" sulfur to the electrolyte solution, revitalizing it. Secondly, the battery conditioner will charge the battery automatically (like 13.8v) whenever it falls below peak levels (like 12v). Finally, it maintains this peak by monitoring the battery’s state, charging only when necessary, thereby preventing future sulfation and overcharging.
 
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MikeMl

Well-Known Member
Most Helpful Member
Mr Taz,
I have read the patents on Pulse DeSulphators. I have read the glowing reports of success on the web about them. I have built and tested two different versions. I have tested them extensively. I have evaluated and wrote a report on the commercial version as part of a consulting contract.

They do not do anything that a once-per-month "equalization charge" doesn't do better. Google "equalization charge flooded-cell lead-acid batteries". The technique of using an equalization charge has be known and well documented since the early 1900's.

An equalization charge consists of overcharging a flooded-cell lead-acid battery for several hours every month using a constant-current power supply, during which the electrolyte bubbles, stirring the acid, and temporarily raising the specific gravity of the acid, which is what dissolves sulphate deposits on the plates, somewhat rejuvenating a tired battery.

The pulsing circuit delivers short current pulses which over time has a similar effect. The pulsing current has NOTHING to do with magic resonances which "break-up" sulphate crystals.
 

marcbarker

New Member
Edit to just pointing out this posting below is me responding to wild claims by marketing people who claim some kind of "magic", and is me ranting about these marketing people! :)

The pulsing current has NOTHING to do with magic resonances which "break-up" sulphate crystals.
When marketing a product, it needs a 'magic ingredient' of some kind, even if it just a belief with no measureable proof. Cola drinks is an example.

This fancy 'new' magic conditioning thing sounds like the special ingredient in a network marketing scheme, it doesn't neccessarily need to work, just be believed to. Have you seen those supposed devices you plug into your power line that supposedly reduces your energy drain by changing the electric current phase? It's a bit like religion, or a snake oil product, you get believers and non-believers.

Alarmbells for me was the choice of words (highlighted) in the belief statement:

First, it can recondition a used battery by sending small, resonate electronic pulses through the battery to break down moderate levels of lead sulfuric crystals. This not only cleans the plates but returns the "escaped" sulfur to the electrolyte solution, revitalizing it. Secondly, the battery conditioner will charge the battery automatically (like 13.8v) whenever it falls below peak levels (like 12v). Finally, it maintains this peak by monitoring the battery’s state, charging only when necessary, thereby preventing future sulfation and overcharging.

I can read between the lines of above and see where this might be going. Person A believes in it, but the more person B (and C,D & E..) tries to point out to person A that it's about as valid as the Wizard of Oz, the more person A believes in it.

Sorry to seem to pour cold water on the marketing aspect of this, but to me the carbon footprint cost of the marketing and operating the distribution network for a 'product' alleged to reduce degradation of leadacid cells, I' would say outweighs the delayed carbon footprint cost of batteries, I'm sure others will agree.

If you're a good salesman and can sell snow to the Eskimos, go for it, market the product, but it's a fiercly competitive world out there, if you're not, forget it!

If you're interested in developing the actual 'technology' of pulse conditioning itself, then yeah go for it!, see if you can prove it works and publish the results here. And if you find you have invented something unique and beleiveable that it 100% yours original, and others believe you, market it!

By the way to confirm the credibility of techniques in the early 1900's, I'll attest to that. Example. I used a recipe from a 1920's book for reclaiming a totally sulphated up battery (it was totally white inside), replacing the electrolyte with a salt (I think it was sodium sulphate maybe) that caused some reparative ion exchange to go on (that or something. It worked, but I'd rather just of bought another battery!
 
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taz128

New Member
Thank you for your response. But I think I’ve got misunderstood. I will try to explain better what I´m looking for:
I have an old car (Citroen C6 from 1928). I used it once or twice a month. But when I try to turn it on, the battery is discharged. So I have to charge it with a “battery charger”. But this goes death in a year more or less so I have to buy a new one. What I would like to have is a battery charger that can recharge and discharge it many times a day (like having the car riding). So if I have the battery in a working cycle I think I can make it “live” for more than a year.
Sorry for my English,
 

marcbarker

New Member
I think I understand the logic behind your thinking now. And what's your first language please?

I think that the idea is this: It is noticed by many people that when a car is being used daily, the battery doesn't degrade and fail so often, compared to a car that is left standing for a month at a time. So it's reasonable to assume (incorrectly) that the battery getting some "excercise" is the only thing that prolongs it's life. It's not true for LA batteries, if they are well-fed (but not overfed) and lazy they practically last forever.

I'd check the battery drain while it's installed in the car, see what the standby current drain is. If it's something like 50 mA, then that current adds up over time and equals a lot of Amp/hours over just 1 week. Classic car owners often install "battery isolator" switch. They also use a charger too, nothing special, just one that doesn't overcharge, that's all. Otherwise the charger costs more than the battery.

I think that what this thread can be about now, what to look for in a charger?
 

taz128

New Member
My first language is Spanish.
I have a battery isolator and a charger that doesn't overcharge. But I connect it the day after I will use the car. I know that a friend of mine have a "charger and discharger" unit but the person how build it have died. I have opened the unit but the chips on it have the identification deleted. So I can´t copy it.
 

MikeMl

Well-Known Member
Most Helpful Member
Mr Taz,

First read this thread. Lots of useful background info there:

Ok, for a flooded-cell lead-acid battery there are basically three ways to do long-term battery maintenance:

1). Use a well-regulated constant-voltage power supply that puts out 12.9V to 13.1V as a "float charger". Such a supply should by design be "current-limited" to between 0.5A to 2A, so that if connected to a mostly discharged battery, it doesn't catch fire :) You can build your own with an AC powered wall-wart that puts out ~15V DC, followed by an IC regulator like an LM317. Such a "float charger" can be left connected 24-7. I get five years or more of service from float-charged batteries.

A long-term "float-charged" battery will benefit from a once-per-month "equalization charge", for which you need a separate constant-current supply (I use a lab supply which has built-in electronic current limiting). Google "equalization charge".

2. Use a well-regulated constant-voltage power supply that puts out 14.1V to 14.5V connected to a wall-clock timer that comes on 1 hour each 24 hour day. This simulates driving the car for an hour a day. The voltage setting matches what most automotive Voltage Regulator are set to. You can also build one of these inexpensively. This charger should also be current-limited to less than a few A. Using this method, the "equalization charge" is less important, but still helps extend the battery life somewhat.

3) Buy a commercial product like the Battery Tender or the Battery Minder. Here is where we get into the Pulse-Charging Snake Oil, however, based on the experience of my flying friends, these microprocessor-controlled three-state battery chargers do a fine job of "maintaining" (preventing self-discharge) of little-used batteries, prolonging their life much beyond what you have been experiencing.
 
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marcbarker

New Member
My first language is Spanish.
Hola! No es problema. Estoy estudiando espan~ol ahora! I have been learning it for a few months. Spanish thoughts in english palabras esta mismo ingles pensando in spanish words!

I know that a friend of mine have a "charger and discharger" unit but the person how build it have died. I have opened the unit but the chips on it have the identification deleted. So I can´t copy it.
The scraped off chip idents are only a deterrent. If you draw out the schematic with anonymous blocks for the IC's, it's often possible for an experienced person to work out what the IC's are. Often the IC's chosen are an improvement on the original design.
 

taz128

New Member
Marcbarker, I have been reading about the charger, And I think that you are right. I need a charger that "charge and have a maintenance cycle". Like MikeMl said, a "float Charger".
I have found a circuit from velleman.
Velleman Inc.
This is a "LEAD-ACID BATTERY CHARGER/CONDITIONER". What do you think about it?
Thanks
 

MikeMl

Well-Known Member
Most Helpful Member
I notice that the manual says that the long term float voltage is 13.5V, which is too high for a flooded-cell battery; it is about right for Sealed-lead acid batteries. As long as you can adjust it downward, it should work.

It seems horribly complicated for what it does in terms of parts count.
 

marcbarker

New Member
unfortunately, I can't get this computadora to open the vellemen pdf file, so I can't comment on it.

Have you thought of getting ready-built cargadores de bateria para plomo de acido, facil? :) I have one that has a row of LEDs, that when charged, the LEDS pulsar. It allegedy 'doesn't over-charge' the battery.
 

Boncuk

New Member
Hi taz128,

you might get a good qualitiy maintenance charger using an UC3906 (Texas Instruments)

This circuit prevents current flow to any load while the battery is being charged in order not to get erroneous readings for the chip.

The chip was designed to charge SLA-batteries (Sealed Lead-Acid), but it will certainly also work for wet batteries.

Here is the schematic. If you also want a PCB layout pleas PM me your email address for the Eagle files.

Boncuk
 

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MrAl

Well-Known Member
Most Helpful Member
Hi,


Anyone ever look into the possible desulfation of lead acid cells that
are gel instead of liquid acid?
 

bountyhunter

Well-Known Member
All that will do is wear the battery out prematurely. Please cite a reference that shows that cycling a lead-acid battery does anything but wear it out.
You are correct, lead acid batteries are basically fixed total energy lifetime devices so using them does wear them out.

The only positive value for a battery "conditioner" could be for NI-CADs if you are trying to cycle them out of a memory problem.
 

bountyhunter

Well-Known Member
Thank you for your response. But I think I’ve got misunderstood. I will try to explain better what I´m looking for:
I have an old car (Citroen C6 from 1928). I used it once or twice a month. But when I try to turn it on, the battery is discharged. So I have to charge it with a “battery charger”. But this goes death in a year more or less so I have to buy a new one. What I would like to have is a battery charger that can recharge and discharge it many times a day (like having the car riding). So if I have the battery in a working cycle I think I can make it “live” for more than a year.
Sorry for my English,
Perhaps I can help, I have been a EE for 35 years and the last 20 I specialized in charging systems for various rechargeable battery chemistry types:

Here is what you need: a temperature compensated battery tender, which is a charger that holds the battery at about 13V (adjusted for temperature) which is just enough to trickle a very minute current into the battery. That will keep the battery charged and healthy. The temp compensation for a 12V lead acid battery is about -14 mV/Deg C and the nominal set point is about 13.2V @ 25C for a storage charge device.

I have been using such a charger on my motorcycle battery (which sees irregular usage) and they typically last about 8 years.
 

MikeMl

Well-Known Member
Most Helpful Member
Perhaps I can help, I have been a EE for 35 years and the last 20 I specialized in charging systems for various rechargeable battery chemistry types:
...
Perhaps you would read and comment on my earlier post to this thread having to do with "pulse charging"?
 

bountyhunter

Well-Known Member
Perhaps you would read and comment on my earlier post to this thread having to do with "pulse charging"?
I haven't seen this particular "technology" or read up on it, but my understanding is the same as yours. I have never heard of any "pulser" that magically resonates with sulfates and destroys them.

It sounds like a scam to me, but I would like to read test data if there is any from an independent testing facility showing that it actually works. I tend to be pretty cynical because of all the scams related to battery charging I have seen over the years (like rechargeable alkalines a while back).
 
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