interesting way to do home boards

Hmm, I just regenerated 4 ACDelco batts this week....2 group 27 starter marine and 2 group 24 deep cycle. Plus an ordinary 9 plate, 36Ah scrapped batt that was in the weather for 20 months ...down to 1.7V....back at 350 Cranking amps and 20Ah, overnight!
All I can say is don't dump it....I will get around to kitting a lower power version of my solution for the DIY guy, such as yourself.
Kinda tied up with the World Bank Regional Angel Investor Network to take the current version commercial.

There is the chance that this procedure might help:
1) Use jumper cables and connect the dead batt to a good batt for about 10 to 20 mins. It should get up to 12V+
2) Connect a brake lamp or 12V downlighter and drain the old batt down to 11V.
3) Do this about 3 times.
4) Then place it on your regular charger.

It's called reflex charging and does form part of my process. Now I've given you one of the 11 secret herbs in my fried chicken, because you're from Scotland and I like bagpipes, a lot.

It was down to around 10V, I charged it to 13V as it wouldnt take any more than that. With the meter on it slowly dropped 10mV every few seconds. Take the meter off and then put back on and its 13V again. The little green led inside the battery isnt lit. I better check the water level on the plates as well, I forgot to do that. I also have 98% sulphuric acid I can dilute if needed. This is a deep cycle battery, next to zero use on it.

I will give what you say a go, it is around 135Amp hour from memory. Big Ass battery size wise, about twice the size of a normal one and intended for marine use. I was expecting around 13.7-14V charged but its bang on 13V, that could be my charger though.

Thanks for the tips, I know you worked on this for as long as I have been here .

13 is ok for a batt. if that's is resting V. Supposed to get upto 14.4 under charge.

Mosaic said:

13 is ok for a batt. if that's is resting V. Supposed to get upto 14.4 under charge.

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Under charge its also exactly 13V. But I got a feeling my charger charges at 13V..........

I did wonder as our car charges at 14.4-14.7V
I will check my other charger, after I discharge the battery and check fluid levels etc. I would hate to loose this battery, it cost a fortune when I got it.

Your battery should be recoverable as it's sulphated due to not being used. I had the same thing happen with some sealed lead acid batteries when we came to Australia, they were in storage for about 18 months and would only hold a charge for a day or two with no load!!. I used one on an electric fence and charged it daily. Within a week it was holding charge for a week and soon for months. I believe the electric fence acted as a desulphator. Here's **broken link removed**of said devices. Also, there are lots of schematics available - google.

Mike.

Pommie said:

Your battery should be recoverable as it's sulphated due to not being used. I had the same thing happen with some sealed lead acid batteries when we came to Australia, they were in storage for about 18 months and would only hold a charge for a day or two with no load!!. I used one on an electric fence and charged it daily. Within a week it was holding charge for a week and soon for months. I believe the electric fence acted as a desulphator. Here's **broken link removed**of said devices. Also, there are lots of schematics available - google.

Mike.

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Mike your a genius.................. I got a electric fencer but its main powered. However the battery ones are fairly low current pulses out of the battery?? If so it seems I need to aim for discharging slowly over a day using a pulse. Then charge (trickle or full power?) each day and repeat.

I take it the sulphate is lead? Hmmm pretty non reactive.....So chemically would be difficult to remove the sulphate from the mesh plates without damage. Which is a shame seeing as Lead nitrate would electroplate back on easy. I also got a couple of dead car batteries (yeah I am lazy with winter charging), I buy cheap batteries each year for the tractor. Works out cheaper than charging all winter.

but I might play with chemical methods of de sulphating and relating. Thanks again guys, saves me chucking alot of money away.

Little Ghostman said:

Under charge its also exactly 13V. But I got a feeling my charger charges at 13V..........

I did wonder as our car charges at 14.4-14.7V
I will check my other charger, after I discharge the battery and check fluid levels etc. I would hate to loose this battery, it cost a fortune when I got it.

Click to expand...

Hi,

13v is way too low. If your 'charger' charges at that voltage then either dump it or fix it.

The way to charge is to apply the current you want to charge at, not the voltage you want to charge, at, and then allow the voltage to find itself, only limiting it once it gets too high like around 14.5 volts or so.

I used to have to bring my battery into the house to charge once in a while. I would charge it at a higher voltage than the car did and it would stay at a higher voltage for a while when put back in the car for normal use. The max voltage allowed was maybe 14.7v. I would set the power source to 14.7v or so and then set the current limit to maybe 3 amps, then connect it up. the current limit kicks in first only allowing the battery to take 3 amps, then once the voltage gets up close to 14.7 the current drops down and the voltage starts to stabilize. After a while like that, it's charged and ready to go for another three months

The most important rule is you have to have enough voltage to charge with or else you can never charge the battery correctly. Not all automobile chargers will work well enough for this because some of them depend on the line voltage which may be lower than usual at some times during the day. It's best to use a good regulated supply.

If you dont have a regulated supply with current limit too, then you cau use a regulated supply without current limit if you use a series current limiting resistor. The resistor limits the current while charging, and after some time you can lower the value to push the current back up there and thus charge faster. As long as you never go over the max voltage for your battery you're ok.

Little Ghostman said:

I take it the sulphate is lead? Hmmm pretty non reactive.....So chemically would be difficult to remove the sulphate from the mesh plates without damage. Which is a shame seeing as Lead nitrate would electroplate back on easy. I also got a couple of dead car batteries (yeah I am lazy with winter charging), I buy cheap batteries each year for the tractor. Works out cheaper than charging all winter.

but I might play with chemical methods of de sulphating and relating. Thanks again guys, saves me chucking alot of money away.

Click to expand...

Chemical desulfation reduces battery capacity. The battery life will be shortened as the chemicals (EDTA?) attacks good soft sulfate as well as bad hard sulfate.
However, without a smart desulfator on hand it may be your only option, but Exercising the battery with a proper charger can also work once you're not looking for overnight results.

Mosaic said:

It's called reflex charging and does form part of my process.

Click to expand...

Hi, does this work on AGM batteries too? I've got a brand new Optima that I bought for a project that then has been stalled for several years. And now the battery won't keep a charge, all it was doing was sitting unused. I know I should have bought a 'battery tender' for it now, but didn't then. Thanks for any information you can give.

Can work on all lead acid types.

Seems I really ought to look at the DIY kit version sooner than later. Just recovered another 9 plate battery as we speak....18 months with no charging, wet cell. Result = 100% cranking amps and 66% Ah after 16 hours of regeneration.

The charger was fairly new and around £75 so called smart charger, it charges at 2A and 13V by the looks of it. I am loathed to used my HP bench supply, but it might be an option if I limit the current on it.


Mosaic I was thinking more radical than EDTA lol. I got another battery that dosnt matter, maybe I will see what a little HCl can do . turn it into chloride (all lead sulphate gone), try and re electroplate the lead then empty chloride and put Sulphuric back. Yeah chlorine will be a problem (so will do in the fume hood), and likely wont work.......in fact 0% chance the more I think of it.

I will try the long way for now. I probably still got my old battery charger somewhere, i will give that a shot.

Do not put anything with choride in the battery. You can create green chlorine fumes and the battery will be trash.
Don't try experimenting with acids and odd chemicals...leave that for chemists.

I don't use additives at all...

Mosaic said:

Do not put anything with choride in the battery. You can create green chlorine fumes and the battery will be trash.
Don't try experimenting with acids and odd chemicals...leave that for chemists.

I don't use additives at all...

Click to expand...

Why you want to go spoiling my fun :. I know its pointless, and I am aware of the chlorine. The bigger problem surely would be the metal plates?
Not that it matters, I pretty much decided it was a bad idea anyway. But I have a pretty decent lab at home (chemistry/Biology), so the fumes wouldnt have been an issue.

What I didnt consider was the metal plates , I guess there isnt a quick fix!! Thanks for the help. Looks like I better check my charger tomorrow, I thought 13V was a bit low.

What should a unloaded 12V battery read anyway? I assumed around 14V but I dont actually know.

Oh and it is a little low on water, so will distil some water tomorrow and top it up, any idea what the specific gravity should be on a deep cycle bat?

Once the water is over the plates don't add any.
SG should be around 1.270, more for a starter batt.

Ok cheers!