Can suphation be reversed ?

[Top cat]

I see that there are quite a few gadgets that claim to desuphate lead acid batteries some of them from reputable names. Even my Ctek charger claims to have a desuphation mode. So my question is can the capacity lost to suphation be recovered by electrical trickery or is this just more marketing hype ?

 

regards

 

TC

[Guest]

I see that there are quite a few gadgets that claim to desuphate lead acid batteries some of them from reputable names. Even my Ctek charger claims to have a desuphation mode. So my question is can the capacity lost to suphation be recovered by electrical trickery or is this just more marketing hype ?

 

regards

 

TC

Some stuff here, and comments from Gibbo who has tested such devices, but alas no longer seems to post:

 

http://www.canalworld.net/forums/index.php?showtopic=38250&st=0&p=690306&hl=desulphation&fromsearch=1entry690306

[blodger]

It can never be totally reversed but a fair amount can depending upon the general health of the batteries otherwise.

 

The most effective method is a monitored overcharging at a higher voltage depending upon batteries but for standard open lead acid 16.5 volts at low current after the batts have been charged ordinarily to as full a SOC as they get.

If the batts are knackered in some other way the current will not be low and/or the batts will heat up; hence the need to monitor. A few hours of overcharging will achieve what is achievable. Some reckon a quick discharge and charge straight afterwards does a bit more good.

 

It depends on your nature and it's a bit like ecofans whether pulsators work. It makes some people happy to see an LED flashing away on a magic box connected to the battery. I think it is fair to say they do no harm but you perhaps might have been better putting their cost towards the next new battery.

 

In contrast the batt aids/EDT addatives may appear to help for a short while but need repeating till they knacker the electolyte IMHO. I think either worth a try before ditching a battery as with it and a good long charge they may survive another season; more so starter batts.

[Sir Nibble]

I once had to deal with two identical 110Ah batteries taken from a yacht that had been laid up for some time. They were both so flat as to show an open circuit voltage of about 3V! I charged them both at about 16V but neither would come above 1200 SG. So I discharged them right right down and gently charged them BACKWARDS until SG stopped rising, flattened them again and charged them normally. One remained most certainly deceased with low SG and woeful current delivery (high internal resistance)but the other came up to a uniform 1280 SG and tested out to it's full capacity! I always maintain that batteries are made of lead, acid and sheer bloody mindedness, the things seem to do as they please!

 

more so starter batts.

Definately. A starter battery may rot down to a quarter of it's nominal capacity and still start the motor cheerfully.

[NB Willawaw]

I believe he has flounced off over a spat.

Did it myself in 2006.

 

He'll be back !!

 

and comments from Gibbo who has tested such devices, but alas no longer seems to post:

[WotEver]

I believe he has flounced off over a spat.

I never had Gibbo pinned as a flouncer...

 

Punch you in the mouth if you upset him yes, but flounce...?

 

Tony

 

I think it is fair to say they do no harm...

That wasn't Gibbo's experience in the above linked thread...

Some batteries got immediatley better. Some batteries got immediately worse. Some got immediately better only to fail totally within a matter of hours or days at the most. Some batteries seemed to be no different whatsoever.

[smileypete]

I see that there are quite a few gadgets that claim to desuphate lead acid batteries some of them from reputable names. Even my Ctek charger claims to have a desuphation mode. So my question is can the capacity lost to suphation be recovered by electrical trickery or is this just more marketing hype ?

They just MIGHT have some effect, but there's no guarantees.

 

I'd expect IF they work at all they only work on a fully charged batt that's under charge, and have no effect if the batt is in use.

 

There's a kit available from Courtiestown Marine that look like one of the better ones, some of the ready made ones even costing ££££ seem a bit weedy.

 

Having said all that, for flooded non sealed batts, it might be possible to recover a useful amount of capacity using a short mild equalisation charge each day, say 1-2hrs day at a current of C/50 (C being batt capacity)

 

This is quite easy to set up with a decent mains timer, power supply, and some sort of current limiting resistor/bulb. Doing it on a timer means the batts won't get hot and use a lot of water in a short space of time.

 

ETA: There's even a forum dedicated to desulphators.

 

cheers,

Pete.

Edited September 27, 2011 by smileypete

[blodger]

 

blodger, on 26 September 2011 - 09:10 PM, said:

 

I think it is fair to say they do no harm...

That wasn't Gibbo's experience in the above linked thread...

 

Gibbo, on 16 May 2011 - 09:06 PM, said:

 

Some batteries got immediatley better. Some batteries got immediately worse. Some got immediately better only to fail totally within a matter of hours or days at the most. Some batteries seemed to be no different whatsoever.

 

I suppose it can be interpreted differently but I see it that the batts were going to do what they were going to do anyway whatever was tried on them so that the pulsars were irrelevant

[Pretty Funked Up]

Here is a suggested method for light sulphation

 

"Light Sulfation

Apply a constant current from one to two amps for 48 to 120 hours at 14.4 VDC, depending on the electrolyte temperature and capacity of the battery. Cycle (discharge to 50% and recharge) the battery a couple of times and test capacity. You might have to increase the voltage in order to break down the hard lead sulfate crystals. If the battery gets above 110° F (43.3° C) then stop charging immediately and allow the battery to cool down before continuing."

[dor]

My set of Numax sealed batteries showed clear signs of sulphation after about 18 months. Disappointed, I bought some open cell batteries which showed the same results after about 12 months. I know that my boat usage was going to challenge the batteries as we tended to go out for two or three days and not travel enough going home to recharge the batteries.

 

So I dug out the old Numax batteries and put each one on a battery charger for a couple of days floating at about 13.6V, followed by 12 hours at about 15V off a bench power supply. They took only an amp or so being fully charged, but that did seem to rejuvenate them. They went back on the boat and are now over four years old and still in service - quite good by all accounts for this type of battery! Having said that, fitting a 100W solar panel last summer has done much to prolong them by charging them up for a few days when we are not on the boat.

[NB Willawaw]

Numax batteries often get a bit of bad press on here, so its good to hear this.

 

My set of Numax sealed batteries showed clear signs of sulphation after about 18 months. Disappointed, I bought some open cell batteries which showed the same results after about 12 months. I know that my boat usage was going to challenge the batteries as we tended to go out for two or three days and not travel enough going home to recharge the batteries.

 

So I dug out the old Numax batteries and put each one on a battery charger for a couple of days floating at about 13.6V, followed by 12 hours at about 15V off a bench power supply. They took only an amp or so being fully charged, but that did seem to rejuvenate them. They went back on the boat and are now over four years old and still in service - quite good by all accounts for this type of battery! Having said that, fitting a 100W solar panel last summer has done much to prolong them by charging them up for a few days when we are not on the boat.

Edited September 27, 2011 by NB Willawaw

[Sir Nibble]

Here is a suggested method for light sulphation

 

"Light Sulfation

Apply a constant current from one to two amps for 48 to 120 hours at 14.4 VDC, depending on the electrolyte temperature and capacity of the battery. Cycle (discharge to 50% and recharge) the battery a couple of times and test capacity. You might have to increase the voltage in order to break down the hard lead sulfate crystals. If the battery gets above 110° F (43.3° C) then stop charging immediately and allow the battery to cool down before continuing."

So to peraphrase. "leave them on the boat and run the engine".

[Pretty Funked Up]

So to peraphrase. "leave them on the boat and run the engine".

 

you'd need a digital 'style' charging method to force a constant 2 Amps for 48hrs surely.

[Bob18]

Make a feature of it.

Attach a large square biscuit tin lid to a suitable flat surface, with its open side up.

Place a marble in the tin lid.

Calibrate the location of the marble with the state of your various tanks etc.

 

Once calibrated you will know, at a glance, the state of the loo, fuel, and freshwater tanks, all while consuming your first cuppa of the day....

[alan_fincher]

Make a feature of it.

Attach a large square biscuit tin lid to a suitable flat surface, with its open side up.

Place a marble in the tin lid.

Calibrate the location of the marble with the state of your various tanks etc.

 

Once calibrated you will know, at a glance, the state of the loo, fuel, and freshwater tanks, all while consuming your first cuppa of the day....

Quite possibly, but does this have any effect in desulphating batteries ?

[blodger]

Quite possibly, but does this have any effect in desulphating batteries ?

It cannot do them any harm and possibly more effective than direct action magic

[Sir Nibble]

you'd need a digital 'style' charging method to force a constant 2 Amps for 48hrs surely.

No, to get the recommended 2A at 14.4V for 48hrs you would need to change the laws of physics.

[WotEver]

No, to get the recommended 2A at 14.4V for 48hrs you would need to change the laws of physics.

They've made a start on that at CERN...