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The one I have is an EnergyTeach one, it was a $70 one that someone here recommended;
http://www.ebay.com.au/itm/370813890285?ssPageName=STRK:MEWA X:IT&_trksid=p3984.m1423.l2649
Great compact design and instructions, they gave a great warranty.
I have 6 battery's that all appear to be improving, as they go right through the full stages of recovery, another 2 are a little dubious, and there is a 4 battery Gel cell Thumper pack that I will try to recover as the stored voltage is only down to 12.3v.
Other than the hick-up, the Desulphator works great.Small minds discuss people, Average minds discuss events, Great minds discuss ideas, Be GREAT !
See this Great engine with No Crankshaft: http://www.revetec.com
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 01:23pm 01 Feb 2015
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Hi Madog
Looks like a good unit for recovery, however I like the type that can be left on the battery to constantly desulphate as it saves the battery from equalization boil up every cycle that in my opinion shortens the life of the battery by boiling off some of the active plate material each time and boiling out some of the electrolyte.
Your unit is good for initial battery rescue and then put a lower intensity desulphator on to keep the sulphate at bay.
Is the one mentioned a few pages back a low Intensity type ?
The one where the parts came from J-Car.
Also is this a "one desulphator per battery" to be moved around &/or can it be used to desulphator a few or a Bank of battery's ?
Also a sparky mate wanted to know what is the best frequency etc. to use ?
Regards
Den
Small minds discuss people, Average minds discuss events, Great minds discuss ideas, Be GREAT !
See this Great engine with No Crankshaft: http://www.revetec.com
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 03:38pm 03 Feb 2015
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Hi Den
I am still waiting for some bits to finish the desulphator mentioned earlier, but from what I understand of the design it is a low to medium impulse suitable for leaving on the battery all the time, the guy that designed / adapted the circuit had that in mind when he built it.
Looking at the design of the unit the intensity of the output is governed mainly by the charge capacitor and inductor combination in the output stage and the rating of the fast recovery diode, most designs use the 555 as a driver, some with an extra driver stage before the Power FET I believe this would give a higher output and be more suitable for desulphation on a one of basis rather than being left on all the time.
I personally would use one per battery to minimize losses in the bank and be sure that each battery gets a good signal, that is why I am going to make a number of these units to go across each 12 volt pair of batteries, at the moment I am using one across each 24 volt shelf in the pack, it is OK but I think it could be improved on with more units. To do what I want would mean buying 24 units @ 12 volt and at over $60 each now our dollar has done a nose dive I decided to have a go at making some. Suffering from AIDS ( Acute Income Deficiency Syndrome) also known as Pension.
Note the desulphator across the 24 volts at the moment these are commercial units Infinity brand that have worked well for me and are rated for 1000 AH.
I have a battery that the top burnt out of in a fire in my shed several years ago and it sat under the bench flat for two years, after I cleaned all the ash and melted plastic off the top of it, I decided to have a go at reviving it.
The lead connectors in it where covered in white sulphate once I cleaned the burnt an melted plastic off and the top of the plates where a mass of sulphate, now several months later it has all cleaned up back to nice grey lead on the connector and no sulphate on the top of the plates, proof that they do work contrary to what a lot of the USA experts say. Note the sulphation on the connector on the left side of the picture.
On the frequency to operate at, most units I have seen operate between 20KHTZ and 60 KHTZ fundamental frequency, different batteries have different frequency requirements but in practice these devices are producing harmonics up to 5 / 6 MHTZ, you can check this by using a AM radio and listening to the output of the unit.
Rustyrod is making some as well and may well report his results here.
All the best
BobFoolin Around
gww1 Regular Member Joined: 14/06/2013 Location: United StatesPosts: 63
Posted: 04:00am 08 Feb 2015
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Bob
Have you got your grass cut yet? I hope all is well with you.
gww
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 02:16pm 08 Feb 2015
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Hi Gwwi
Still cutting, we had a bit of rain and it is growing faster than I can cut it, second time over this week 20 acres in all so it does take a bit, the first cut got most of the weeds that fire up first, and the second cut is getting the grass.
I have done a light load test on the batteries over the last week with a 500 watt inverter running 24 / 7 and voltage is staying between 26 volts and 28 volts, just connected to the 400 watt boost panels.
Hope to fit the new inverter this week after doing the brakes on the wife's car and finishing the mowing, got some 250 amp welder cable for the new cables to the inverter, so will make the terminals for that this afternoon. Still haven't got around to shifting bank 3 yet, but I have finished re hydrating it, it wasn't as bad as the other two as it is only 10 years old, the batteries are not as good quality as bank 1 and 2 but seem to be holding up alright.
I am going to use bank 3 as the workshop supply using the old inverters that are lossey when left on all the time, they are OK for short term use and as I do not do allot of work in the workshop in the heat at the moment. They run all the 240 volt things including the welder and plasma cutter so are very useful.
All the best
Bob Foolin Around
gww1 Regular Member Joined: 14/06/2013 Location: United StatesPosts: 63
Posted: 02:51pm 08 Feb 2015
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Bob
I live on 21 acres but I only cut about 3, I give the neibor the other 4 acres or so that is open to use as hay for his animals. Keeps the sprouts from getting out of hand. Sounds like everything is progressing well enough on your batts. Hope they last forever.
gww
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 05:19pm 08 Feb 2015
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Hi gww1
My place is a airfield so that's why I have so much mowing.
We have had a drought here for last year and only mowed once but now it is catching me up.
I had the neighbors cows in for a while but they did more damage than good, destroyed my fruit trees and dug dust baths in the runway so now back to the hard slog of mowing.
I hope my batteries last a bit longer but we all got our use by date but they may outlast me.
All the best
Bob
Foolin Around
gww1 Regular Member Joined: 14/06/2013 Location: United StatesPosts: 63
Posted: 05:37pm 08 Feb 2015
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Bob
Are you the flier? I just planted 15 fruit trees last summer, I am going to try some grafting on some sucker stock to try and save my last asian pear. My last previous fruit trees except the pear died last year.
I don't need cows, I can destroy fruit trees esily with out help.
gww
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 03:13pm 09 Feb 2015
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Hi Gww1
The drought here and the higher than usual spring temp killed a few of my trees and the rest are just hanging on at the moment, and with me at 50% I do not look after them as i should. my concentration has been on getting my electricity system revamped to be independent of the power companies as they are getting out of hand with their fees and charges.
I am hoping the new inverters will make the difference in efficiency I need as the original ones where power hungry and needed another KW of power panels just to make up for wasted power. I have another 4 KW of panels to put up and a couple more windmills so all I need now is the get up and go to do it.
All the best
BobFoolin Around
mab1 Senior Member Joined: 10/02/2015 Location: United KingdomPosts: 209
Posted: 01:33am 10 Feb 2015
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Hello Bob,
Just joined thebackshed today, but have been reading and catching up on this thread for a while with interest. I have a small off grid setup which has run on a 100Ah 24v AGM battery (yuasa ENL100FT) for a few years.
I recently acquired eight Yuasa 160Ah, 6v AGM batteries EN160-6 (which are a bit tired but showing >2v per cell) to supplement the existing battery (which probably needs re-hydrating and has developed slight bulges in the sides of the cells).
I've been rehydrating them (something like 200ml per cell on average) and gently charging them long enough that they must be as equalised as they're going to get, but they're still unbalanced with some cells showing 2.15v whilst others are pushed passed 2.5v and venting.
I have generally considered desulfators as 'snake oil' TBH but then maybe I haven't run one for long enough. I have built the one quoted earlier in this thread (based on a 555 timer and a 9Z34 Pfet built for 12v). When running across the worst pair of 6v blocks it generated peaks of about 30v (using a fast diode, a 3.3uF cap and an old AVO8 to measure peak volts) whilst getting quite hot and drawing 1/3rd amp from the battery/charger.
If I could ask you a few questions I would be grateful for your opinion:
1. How would you rate this DIY desulfator's effectiveness vs the infinium devices? (I don;t really want to spend my ££ if I can avoid it)
2. You seem to prefer the 12v desulfator rather than 24v - why? (if I have to make another 12v one I can but then there are issues of load balancing between the two halves of the 24v bank and I wonder how the spikes from the two desulfators may interact)
3. I read on the Rolls/Surette traction battery website about using a 'recovery charge' on sulfated batteries: - IIRC they recommended charging at 2.6-2.7v per cell until the specific gravity stopped rising (or until the battery got too hot: >51C). Whilst these aren't flooded traction batteries, they are now effectively flooded (as I've added water) I thought this might be the way to go (if Rolls/Surette recommend it for their batteries it probably isn't 'snake oil' is my thinking.
The problem is this may come under the heading for boiling the batteries which you advised against IIRC as it removes active material from the plates, so I guess the question is what would you consider an acceptable sustained charge rate for a 160Ah cell if I were trying to achieve 2.7Vpc?
M Del Senior Member Joined: 09/04/2012 Location: AustraliaPosts: 155
Posted: 10:31am 10 Feb 2015
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Hi Mab, welcome
You will get no benefit boiling AGMs and will only do harm. In a flooded or wet battery such as the Rolls/Surette the acid or solution is free to move throughout each cell and boiling or equalising will cause the acid to heat and bubble. This results in the acid passing in between the plates throughout each cell(boiling and rising through the plates, cooling and flowing down the sides), this equalises (mixes)the distribution and strength of the acid throughout the cell.
In an AGM (absorbed glass matt) battery the solution is not free to move and boiling it will cause bubbles to form in the matting between the plates effectively drying out parts of the cell which will be practically impossible to correct and will only reduce the life of the battery.
I have not used a desulfator and will defer to Bobs experience,
message to self buy desulfator for emergency batteries Mark
mab1 Senior Member Joined: 10/02/2015 Location: United KingdomPosts: 209
Posted: 11:34am 10 Feb 2015
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thanks mark,
I did wonder about it, and I was thinking it may be viable because AGM's seem to rise to a higher voltage for a given overcharge current c.f. traction - so I was hoping to reach 2.7Vpc without causing more than a gentle bubbling - fact is trying to charge these batteries at the recommended float voltage is causing gassing in the high volt cells already.
Of course if the pulse desulfators do work then that is the way to go, but i'm still not 100% convinced TBH, and I was hoping to understand Bob's preference for 12v over 24v desulfators before building/buying them and setting up a months-long experiment, as I'm running 24v anyway.
marcus
M Del Senior Member Joined: 09/04/2012 Location: AustraliaPosts: 155
Posted: 01:12pm 10 Feb 2015
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Mab
Any gassing is causing damage by leaving areas of plate without sufficient moisture.
That is why rewetting is done a little at a time, if you drown the top of the cell and the bottom is dry the air has nowhere to go as the matt is fairly tight.
If you filled the battery with what you think is the right amount of water and the top of the battery is flooded, one idea is to tip it on it's side at an angle that will allow the moisture to penetrate deeper into the matt structure whilst forcing some of the excess air out.
Like most things it is an experiment, as we are supposed to throw these batteries away and buy new ones when they give trouble.
Bob says that desulfators are not something you use for a month and take off, they are long term, try on half your pack, if successful buy more. If not then you have not spent too much. Bob and others have a lot of success with them.
Mark
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 01:17pm 10 Feb 2015
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Hi marcus
Mark has given the explanation on the boiling situation with the AGM and that applies to Gell cells more so, as they have a worse situation with gell bubbling that can do permanent damage to the plates and gell.
In my experience any more than a gentle bubbling of the electrolyte is going to dislodge active material before it can be converter back to acid / lead in the cell pack and it ends up in the bottom as grunge in a flooded battery and in choking the AGM material in a AGM cell pack, in an AGM with excess water as in the rehydration process 30 volts across a 24 volt pack is about optimum, if it is a flooded cell pack going to 32 volts across a 24 volt pack is recommended as an equalization charge and as mark says the convection of electrolyte in the cell avoids hot spots but does remove some of the active material, the electrochemical reaction taking place causes micro hot spots on the plates and that pops active material off to be carried away by the convection currents in the electrolyte.
Once the battery is revitalized the float voltage recommended by the maker and a permanent desulphator seems to keep things in order for a long time, a equalization charge every three months or so will help with batteries being deep cycled, (over 50% discharge)on a regular basis.
There are a lot of skeptics when it comes to desulphators and there are a number of desulphators that do not work to create skeptics, or the skeptics do not use a desulphator properly and get poor results, and using a desulphator on a dud battery and expecting it to work is a pipe dream.
I have used desulphators for 40 or more years and am convinced they work, but only on a sound battery that is just sulphated no shorted cells or grunge build up in the bottom causing higher than usual self discharge. I have used them on all types of lead acid batteries and they work on all of them.
The reason you noted the voltage rise on AGM batteries is caused by the gassing on the plates held in the AGM medium as this increases the resistance of the cell due to the lower conductance of the plates when trapped gas is present on the surface, with an unregulated charge this allows the voltage to go higher, this applies more so on gell cells and is doing damage to the gell.
I have used Infinity desulphators with great success and the only reason I am going to build some from the circuit is the cost of a lot of Infinity units doesn't fit within my budget.
The output of the desulphator can be modified by the combination of the charge capacitor and the inductors on the output stage, so I will be experimenting with that as I want a unit to leave in place on the battery not just to desulphate it and then take off.
The reason for multiple units is that it can more effectively treat a smaller number of cells as the pulse is more concentrated and not so effected by the varying resistance across the cell pack, ideally there should be one per 2 volt cell but on sealed batteries that isn't possible, on the old 2 volt cell, 32 volt systems the desulphator had a number of settings so you could do one cell 3 cells 6 cells or the whole 32 volt pack, at the moment I am using a 24 volt unit across each 24 volt pack in the battery bank, while this isn't ideal it is better than nothing and with batteries in good condition should maintain that state.
On my batteries I have an equalizer link at 12 volts to help balance the string voltage and to use to fit the 12 volt desulphators. My batteries are old 15 years and been revitalized, and rehydrated first when I got them 5 years ago, and this time when they dried out, so I am trying to get a bit more life out of them till I can afford a new set, in the next few days I hope to do a load testing that will determine if I have succeeded in my adventure. One thing I have noticed is that the batteries do slowly gain capacity over a few months and I put that down to the slow desulphation process.I haven't noticed and detrimental effects from multi units but a battery lead ferrite bead on the leads helped to reduce RF interference.
Some of the battery packs I worked on in the dark ages where 20 to 30 years old and still going but the quality of those batteries was better than generally available now. The NIFE pack I salvaged was over 50 years old and still worked to capacity once the electrolyte was changed no desulphation required on them just an occasional full cycle and charge.
All the best
Bob Foolin Around
mab1 Senior Member Joined: 10/02/2015 Location: United KingdomPosts: 209
Posted: 02:32pm 10 Feb 2015
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Cheers for that Bob, I guess the problem with desulfators is that it's difficult to have the patience to setup and monitor the batteries for months when your not convinced it isn't a wast of time - you want to see results TODAY! But as I've acquired these old batteries I think the times come to try...
Having read your posts in this thread I decided to build the 12v desulfator to try but that was only a couple of days ago, and as I used salvaged parts I may struggle to build an identical one, though I may be able to use a trim pot instead of a resistor to balance current draw I suppose.
Actually these 6v 160ah's have external links so I could put desulfators across the individual cells - assuming I knew how to make a 2v desulfator - presumably it would need to use a higher voltage to drive the fet - and assuming I have enough bits n bobs and time to make 12. For now I think I'll be guided by you and just make another 12v one (rather than mod this one for 24v).
I don't really know the condition of these batteries - they don't have shorted cells as they are all >2v even after a week and more off charge, and looking through the vents (when adding water) I can see ice-white (sulphate I assume) tops on all the plates. but they may be old and little used or old with lots of cycles on them - I don't know how to tell. I don't really know how slowly to add water - I started with a 2.5cc syringe but that was taking a long time so went to a 10cc syringe..
Just for a bit of background:-
TBH I don't need a huge Ah capacity - I have a small hydro-electric setup that tends to keep the batteries on float day and night, but just recently I upgraded my inverter (to a powerjack lf8000 - having read Oztules exploits on another forum) and I'd like to use it's extra capacity for the odd short-duration heavy load. As the hydro is only around 300w it doesn't support heavy short-term loads which then fall on the battery - and as my original battery is just 100Ah, if I put a 2kw load on the inverter, that's 80A from the battery and I was worried I might push the 100Ah battery into an early grave.
I have paralleled a couple of old car starter batteries with the 100Ah AGM which halves the load on the AGM and as I'm only taking them a few % off 100% charge they seem happy with it; but if/when the hydro goes offline, then I need to disconnect them quick before they get cycled properly (difficult when it happens when I'm out at work) - hence it would be nice to get these 320Ah worth of old AGMs up and running instead.
Back on topic:
but whilst the best four are OK on float (40mA on 27.2V float charge), the worst four are pulling over 1anp with some cells at 2.15v and others up over 2.5v and gassing - hence I'm starting my experiments with these poor cells - I haven't started adding water to the good set or my original 100Ahs as I wanted to make my mistakes on the worst set...
I was thinking then of starting the desulfators on this poor set (once I'm sure the water level isn't dropping anymore on all cells) but with the set connected to the main bank via a diode or two to drop the float voltage -and hence keep the current down to just over what the desulfators use - so they're floating but not gassing - or do you think a bit over 1a isn't excessive? (doesn't cause vigorous bubbling but will pop the vent caps). If I took them up to 30v they would definitely be gassing more - worrying with Mark and your cautions very present in my mind.
rgds
marcusEdited by mab1 2015-02-12
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 05:37pm 10 Feb 2015
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Hi marcus
it sounds like your batteries have a chance at a second life, but you must be patient with old batteries as it takes time to get the juices flowing again, what you could do is to put the desulphator across one cell if you get a stubborn one but power it from 12 volts much like I used to do with the old glass cell 32 volt batteries. There is no real science to it just suck it and see what happens.
I also used a 10 cc syringe for my batteries but it still took weeks to get the matt properly saturated, I ended up with just enough water to cover the tops of the plates and it seems to work OK, it may lower the SG a little but that's a theoretical problem rather than a practical one.
One thing I have found is we use digital voltmeters reading in 100 ths of a volt and expect the battery to match that when in fact we are dealing with a low tech analogue device and if we can get within a 1/4 volt we are doing well.
If your cells are not shorted and will accept a charge you are well on the way, some batteries I have done I have had ti hit them with 60 volts to get them to conduct initially but they slowly came good.
I like the sound of your hydro system a friend of mine had one that did 500 watts and four 80 watt panels and he run his whole house and office on that, with a good battery bank set up to absorb the power it is a real useful item.
I too have followed Oztules Inverter series and am installing one now to get away from the lossey w7 models, time will tell if these new Power Jack are better than the older disposable HF ones.
You could make the windmill controller featured in the forum to switch to a load on the system once you get to float voltage to save you having to disconnect all the time, a bank of headlight globes works well or an old heating element out of a HWS, or dare I say a low voltage GFI or get a approved one installed and feed it from rectified DC from your inverter, all sorts of possibilities.
On the current to the batteries 1 to 2 amps seems to work well at 27.5 volts, it will take time for all the cells to balance out though, it wouldn't hurt to overfill them a little as they will gas it out over a few weeks, I found out that after the normalize the settle down and gas very little and hardly use any water.
A headlight globe in between the batteries works well as it limits current and tends to regulate the voltage to a degree and due to it's variable resistance, it will stop over current events.
Your 6+ Kw a day from your hydro would go a long way to support the house essential functions.
All the best
BobFoolin Around
Georgen Guru Joined: 13/09/2011 Location: AustraliaPosts: 462
Posted: 01:13am 11 Feb 2015
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Never thought that liquid might just float on the top and never be wicked lower.
But trapping air argument is logical.
Tilting sounds like good idea for air removal.
In my case I added 2 cm3 at a time and it kept disappearing.
I stopped adding water after it didn't disappear, checked it monthly for 6 months and it was there.
Now feel like checking again as it was a while.
Interesting if change in temperature cannot help in soaking up the plates.
When temperature drops, air shrinks pulling liquid down.
I Doubt the glass mat will give all moisture back after temperature rises and air expands again.
20 or 30 degrees changes can make air change volume quite a lot.
To make it easier for air to escape might be trick to connect vacuum to the opening.
What do you think about this idea?George
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 02:11am 11 Feb 2015
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Hi George
I found that it slowly soaks down and the trapped air comes to the top along with the light gassing from charging but it is a slow process as the water has to combine with the electrolyte and then recombine with the sulphate powder that has formed due to dehydration some of the real dry cells took 3 months to stop absorbing water even though they where still working as a battery on the remaining moisture in the pack, it would have been at a much reduced AH capacity though.
I do not think that you need to get a vacuum to aid the process as the slow part is really rehydrating the sulphate so it can be broken down into acid and lead again. A light tapping of the case sides brought some bubbles initially but it took time to soak into the matrix, which I presume was nearly dry as I added nearly 1 liter of water per cell over the two months, one cell with the top burnt off is still absorbing water, but it had sat under the bench for several years as well so was really sick.
Not all cells have responded and I have had to discard 8 batteries due to case leakage internally allowing the electrolyte to be on contact with two cells, I may cut the offending side of and recharge to see if the cells can be salvaged by resealing the side with a piece of lexan just for the exercise, I wouldn't trust them back in the bank but may be useful for something else or to prove a point.
All the best
Bob
Foolin Around
mab1 Senior Member Joined: 10/02/2015 Location: United KingdomPosts: 209
Posted: 12:53pm 11 Feb 2015
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I may have been a little gung-ho with my watering and done them a bit quickly after all - though I did stop as soon as the water didn't soak away immediately - so there's just enough on top to be visible - but as long as they soak it up eventually I'll be happy.
Actually I was thinking that if they were bubbled for a bit, that it would expel anything but oxygen an hydrogen from between the plates, then when they're let stand for a while, the recombination of the gasses would remove the bubbles from the plates and suck the water in - when I let them stand with the rubber vent caps on, the caps develop concave tops and when removed again there's a sucking noise indicated that the resting cells do seem to develop a vacuum.
I've also thought of another question (sorry):-
I gather from your posts Bob that your battery shed is generally quite warm? 30 or 40C + ? I seem to remember from school that ionic solids (like sail of sugar) dissolve better in warm water than cold which made me wonder if the sulfate would dissolve better in a warm electrolyte; i.e. if I want to desulfate my batteries, should I warm them up a bit (my shed is barely above freezing at the moment).
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