Pulse charging

[clivejo]

I have heard good things about using Pulsed voltage or current to charge batteries.  I have a number of batteries which may or may not be any use.  Is it possible to use Pulsed charging to revive the batteries?  If so, where would I get one or find the plans to build one?

[biff]

hi clivejo,
        hope you came through the storm ok.? pulse charging,, well sometimes i do an equalising charge on the xantrex c 40 for 20 minutes or so and believe it or not ,it does help to bring the overall voltage up and enables the batts to hold on to it better.
  the equalising charge might be a different thing but the overall effect is to shake up the cells and clean the plates a little so that the batteries can take and hold the charge better,i guess pulse modulation is another method  of doing the same thing.
                                                                                            biff
                                                                                                   

[clivejo]

I did indeed, it was a very nice storm I must say.  The wee Chinese turbine was just a blurr, pumping out about 200w!

These batteries are from an old Bedford van and I'm not sure of their condition.  If they hold a charge, Ill keep them, if not Ill take them to the scrap man.  Id just heard of this pulse charging malarkey and wondered would it work with virtual dead batteries!

[rogeriko]

Its called battery desulphation. Desulphators are available on Ebay but whether they actually work or not is another story. I have never tried one but many people say they can bring a dead battery back to life. But there again if you have the money to buy one you could also just buy a new battery!!

[biff]

roger i posted on here as to how happy i was with my desulphator,
          i sent off 30 euros or so and was expecting something the size of a loaf of bread,instead i got back an article small than a packet of fags with little fine wires.one look told me i had been had. . "you can only use them alongside a good quality charger",,,,
        the xantrex c40 has a little button on the righthand side which you press to do equalising charge.it does work no doubt about it.
                                                                       biff

[clivejo]

the xantrex c40 has a little button on the righthand side which you press to do equalising charge.it does work no doubt about it.

I dont have a C40 or a little button!!  Need to make do with what I got.  I have an old battery charger so have a coil, rectifier and a fuse!  How could I build one?

[biff]

im on commission clivejo,
                   for every 10,000 c40s i sell i get a book of green shield stamps.
   but,,but they are handy,,the c40s that is,, can be configured in 12 ,24,or 48volt,so if you decide to up your voltage you dont have to dash out and buy a new one.,its got charge mode,load divert and one that says,"please dont do that"
    if i could build a c40 out of an old battery charger,a coil,a rectifier and a fuse i would be rolling in the dosh,however i could build a toaster out of the same gear. it might only work the one time but it would certainly toast.
                                                                                 biff
     

[julian]

Somone one the veg oil forum, whom i trust with this sort of stuff, has had good results with the desulphanators.

Theres a forum dedicated to them somwhere about, i think.

Building one is on my 'to-do' list.

As i understand it, they do not need a fancy charger to work with at all.  But you do need a small charger that will supply the float that the battery is held at whilst the desuphanator is in opperation - i think that is fair enough ; )

[Paul and Rona]

Hi Fellas,
            I think what your talking about is a desulfator rather that just Pulse charging....
I have built a couple of these and whilst they work quite well on WET cells they ain't too good on Gel cells...

**((I Forgot to add)) Whilst they work.. They are NOT fast It often can take a couple of months to see any improvement))**

Basically in it's basic form its a 555 ic producing a short duration pulse at approx 1KHz, this drives into a mosfet which has a small inductive load.

The back emf pulse which is produced is applied directly across the battery terminals....

It's the high current short duration pulse which it's understood "Blasts" the Sulfate Crystals" back into suspension.

Try Here for more info

http://leadacidbatterydesulfation.yuku.com/forums/8


http://www.courtiestown.co.uk/batteries/batterydesulfators/batterydesulfators.htm

Regards Paul & Rona

[clivejo]

http://www.ebay.co.uk/itm/12V-High-Power-LV-Cut-off-Battery-Charger-Desulphator-/200633615796?pt=UK_ConsumerElectronics_Batteries_SM&hash=item2eb6b205b4

Has anyone got one of these? Are they any good?

[biff]

looks like the one i got.
                 its smaller than a box of matches,somehow i could not imagine that puny effort making a difference to my forklift batteries,so i never tried it.
                                                                                               biff

[Stuart]

http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

jury is still out it seems, equalisation charge is always a good idea.

[clivejo]

looks like the one i got.
                 its smaller than a box of matches,somehow i could not imagine that puny effort making a difference to my forklift batteries,so i never tried it.
                                                                                               biff

Well from the instructions it looks like it puts a small, high frequency, high voltage jag into the battery every so often to 'kick' it into taking charge.  As the volts are high and current is low, it does not need thick wires.  The main battery charger does all the work, this little device just jolts the sulphate from the plates and allows the exposed plate to 'charge'.

Wonders would an electric fencer do the same job?   

[linesrg]

Good Evening All,

I need to declare that I am Courtiestown Marine Limited at the outset of this response to this thread. Desulphators do work but really only on conventional flooded lead acid cells. Yes there is a limit to the size of battery they can deal with. We do devices that can deal with anything from a bike battery to one upto 1000AHr's.

The picture I've attached is one sold by an Australian outfit. I've removed it from its case, included a ruler to give a sense of scale and added one of our standard inductors for comparison. The device you see here is meant to be used on 48V batteries. We use ring terminals and 10AWG wire. This device is a joke and gives those of us trying to sell a relatively proven product a bad name.

There is a lot of energy in desulphating at 48V and we don't deal in these voltages currently for that reason.

Regards

Richard

[Eleanor]

Richard, do you have more information on the desulphators that work?