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Forum Index : Other Stuff : bringing an old battery off the death pli
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
G'day Guy's, I found with my Hilux being off the road for 3 months the battery had gone flat so charged it up and got the ute going. The next day it would crank but not fire, so not even current to get the rev's up. So time to do a test and see if it works. As car batteries are sulphuric acid based the acid does break down over time thus losing the full charging reaction needed for a good battery. So first check the sitting voltage to make sure there isn't a dropped cell in the battery. With the donor battery the voltage was 12.4 volts and after I drained the acid out 3 days later the voltage was still 12.2 volts. After 3 more weeks the voltage was 10.4 volts which showed this battery is still fine. Now we want to get rid of all that acid and this is where baking soda comes into it's own as it can act as a base to neutralize the acid. So a 30% mix by volume with rainwater is made and each cell it topped up to within 1/2" from the top of the cell. Bubbling will start straight away and this is what we want as the base is reacting with the acid. Leave the first base in for a few days then drain it out and flush the battery with rainwater by rocking to ensure the water will dislodge any base crystals. But be careful as the solution could still be acidic. Do this 3 times to make sure too. Then make another 30% solution by volume and go for a second round checking for bubbles as we want to have a solution where no bubbles are present we rinse and repeat and do all the steps a 3rd time. Now when no bubbles are present we know all the acid is gone so time to make up the new solution. What we want is Alum which is just Aluminum powder or in my case I went to bunnings and bought some pool flocculant which is Aluminum Sulphate and that is what we want. Make up a 40% solution by volume and stir until the solution is clear then pour the mixture through a coffee filter to make sure no nasty lump go thru. What I use for my battery charger is 3 off 5 watt 12 volt solar panels and I have had this battery on there for a month. The resting voltage is 13.1 after the sun has gone down and the indicator outer edge is showing green where the centre section is void. Tomorrow I will have a go at starting my tractor and it can go into that for the test. I have high hopes for this conversion and will post results as they come in. Regards Bryan |
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isochronic Guru Joined: 21/01/2012 Location: AustraliaPosts: 689 |
I think the lead dioxide electrode will need acid : (from memory) PbO2 + acid (hydrogen ions) + sulphate + electrons -> lead sulphate + water |
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
I put this alum battery in my tractor last weekend it fired up like it was a new battery so let the tractor run for 5 minutes then turned it off. Started the tractor everyday since and instant fire up just like a new battery. Cheers Bryan P.S. Also testing |
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davef Guru Joined: 14/05/2006 Location: New ZealandPosts: 499 |
Hi Byran, Could you provide a reference for this acid break-down or state what it breaks down to? How did you determine that an aluminum based solution would be a good substitute, reference or trial and error? How do you determine if you have the correct concentration of aluminum, S.G.? Obviously, you have something that works ... I am just interested in how it works. Cheers, Dave |
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isochronic Guru Joined: 21/01/2012 Location: AustraliaPosts: 689 |
I have seen reports of using other sulphates to reform the battery and then using the acid again, mostly sodium and magnesium (glaubers and epsoms salts) but no actual measurements of capacity etc. btw There is a battery rescue thread worth checking out here |
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
I was told years ago by a mates dad on how to do it and as this was over 20 years ago I thought I have a go. From my research into chemistry to neutralize any fluid one needs a base and baking soda was a good choice in this application. After 3 rounds of the baking soda solution no bubbles were seen while pouring and observing for 10 minutes, I did check over a few hours and didn't see any so left the solution in for another day then emptied it out followed by rinsing shaking a few times with rainwater. Now if one wanted to be purist one could scrape scrap ali and the powder that comes off is pure alum or one can go the easy route and use the ali sulphate. I worked out I needed just over 3 litres for the 6 cells so I measured out 400ml of the ali sulphate powder and added 1.4 litres of water. Then stirred until it became fully saturated then found with some crystals left I had to add a touch more water as the soulution was fully saturated. It turned out I didn't make enough so I made a smaller solution up and used a sealed beaker to mix the solution which only took a few minutes. The ideal charger is the old type that will over charge a battery if left on or in my case 3 off 5 watt solar panels hooked up directly has proven to be a good charger leaving time to do the job. Now the battery I used still would of started a petrol engine I use diesels and the current draw needed to start the engine is much greater than a petrol. Not sure if I said before but when the battery had no electrolyte in it was still showing 10.4 volts. Depending on the state of the battery will determine the results doing this conversion as if any dead cells are present it won't work. So one might ask why move away from using acid, well thats what the manufactures want you to believe just so you can buy a new battery every 5 years and keep the company in business. The old Edison cell uses a alkaline solution and some cells are still going 100 years later. |
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Georgen Guru Joined: 13/09/2011 Location: AustraliaPosts: 462 |
Quite interested in final results, so keep posting if you can. Had 12V battery that now keeps 10.7 volts, but is OK for some 12V LED lights. Not too bright, but good enough for me not to bump into something while in garage. Sure, use other lights to do something, but to be there only is enough. Use 40W 12V panel to top up. Panel is inside garage, so doesn't produce too much electricity even if it gets to 15V (in short circuit measurement). Sure don't use battery too much, but as emergency quite OK Interesting if I convert it to soda battery it might get back to 12V if I get rid of short in one cell. George |
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Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Perhaps a typo but measuring 15V across a panel inside a shed is called Open circuit Voltage. Quite meaningless in that situation. Do a short circuit test (panel alone, NO battery!) with your multimeter, in the same panel location, you might get a few milliamps. Perhaps not enough to charge a battery. I have one of those solar powered shed lights. It has a tiny solar panel and wire too short to pass onto roof so I fitted the little solar panel under a clear roofing panel. Performance is lousy, barely enough juice into those rechargeable cells for a few minutes light from a full day charging. Klaus |
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George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308 |
What is the actual goal or result here? Is it to restore a battery to as new condition or just to extend some usable life out of it at reduced capacity? I really don't believe any of these chemical rebirths can do all that much. batteries break down and have physical damage. That' can't be restored by a chemical solution. If you are removing some scale or buildup on the plates so you might get some extra life out the thing at reduced AH and cranking amps, I can see the potential for that. If it's to rejuvenate the battery to an as new condition, Would take a hell of a lot of convincing me that's going to happen! |
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Georgen Guru Joined: 13/09/2011 Location: AustraliaPosts: 462 |
Sure, meaningless. Battery sits on 10.65V (with one dead partition) I have it connected to that 40W panel, use battery for LED light a little bit. As long as battery is about 10.6V to me it means that tiny use and little top up are in balance. If it goes lower, I might put 40W battery outside garage and get 2A charge for couple of hours to get back up to 10.6 if I could get rid of short by converting to alum battery I could possibly extend it's life. George |
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Georgen Guru Joined: 13/09/2011 Location: AustraliaPosts: 462 |
At 12.6V it gets up to 90mA. Taking into account little usage and internal discharge it looks like enough to keep battery around this voltage. George |
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
Well went to start the Hilux yesterday and found when the wife drove it last time the ignition switch was left on and the new battery was flat. Thought well it has been a month since I started the tractor with that battery in it, found it kicked over pretty well straight away. So drove the tractor to beside the ute and hooked up the jumper leads then 20 minutes later after a quick charge the ute started. Got another another battery here waiting for the conversion so if the first one works time to see if it wasn't a fluke and see if I can do it again. Cheers Bryan |
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brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Gidday Bryan,and a good new year to you and your mob. I have been playing around with a couple sla 150 Ah batteries that I thought were dead. After leaving them on the solar for a few days ,they seem to come up to around 12 volts . So, I'll put them in parallel with the bank and see if overall voltages drop on disconnect, or stay ok . PS.. don,t throw your batteries out ,,they bring fairly good money at the scrappies ,these days --I go $25 each for a couple of 150Ah brutes. Bruce Bushboy |
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Georgen Guru Joined: 13/09/2011 Location: AustraliaPosts: 462 |
150Ah battery is a lot of lead George |
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