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Epsom salt in lead-acid battery

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floobydust:
What's interesting is the source of ignition. You can't ignite much of anything with only a 2V spark. That leaves heat, hydrogen needs 500°C (932°F) so I am thinking a short happened in a cell, from a glowing lead flake? The battery doesn't look that bad though.

I see badly sulphated batteries just boil away, they don't do much else. This agitates all the corroded pieces. Within a cell, large gas bubbles form under the plates and then come up. I have a habit of tilting a battery to burp all that. But ignition at the bottom you'd think would blow out the bottom. Hmmm the second cell from the left has a bent up interconnect, all others are fine.

It would be good to know the charger model to avoid the whole idea.
I think pulse-charging is pseudo-science, lead sulphate crystals are stubbornly bonded to the plate's pores and after 100 years nothing has really cured it.


--- Quote from: coppercone2 on December 23, 2020, 06:01:40 pm ---it has low density so its not very destructive compared to outlawed things

--- End quote ---
It's the acid spray that makes it extra destructive, to eyes and things.

Rick Law:

--- Quote from: floobydust on December 23, 2020, 09:57:59 pm ---...
It would be good to know the charger model to avoid the whole idea.
...

--- End quote ---

If it isn't too much trouble, I like to know what charger too.

I was in the market for a charger, I went to my local auto-parts store only to see they are selling the same stuff I could get from Amazon or eBay/AliExpress.

Trouble with cheap stuff proliferating.  Paying a higher price means just paying a higher price but not necessarily better quality.

james_s:

--- Quote from: floobydust on December 23, 2020, 09:57:59 pm ---What's interesting is the source of ignition. You can't ignite much of anything with only a 2V spark. That leaves heat, hydrogen needs 500°C (932°F) so I am thinking a short happened in a cell, from a glowing lead flake? The battery doesn't look that bad though.

--- End quote ---

2V? If a cell goes open circuit you have the entire open circuit voltage of the charger, which in the case of one designed for de-sulfating could be pulses of 100V or more. If you have current flowing through a circuit and you open the circuit it doesn't take much voltage to make a spark, shorting the output of a 1.2V NiCd cell will make sparks.

floobydust:



--- Quote from: james_s on December 24, 2020, 04:49:24 am ---2V? If a cell goes open circuit you have the entire open circuit voltage of the charger, which in the case of one designed for de-sulfating could be pulses of 100V or more. If you have current flowing through a circuit and you open the circuit it doesn't take much voltage to make a spark, shorting the output of a 1.2V NiCd cell will make sparks.

--- End quote ---
I'm using the IEC 60079-11 spark tables for hydrogen ignition energy values. I assumed it was a short within a cell that lit up the gas, not an open circuit. I don't see enough corrosion to cause an open circuit in the interconnects. They're built for 100's of amps for cranking.
Maybe at some time in storage it had frozen? That breaks everything up.

Nobody uses epsom salts or pulse chargers in the third world.

G7PSK:
Up until the late 1970's there was a company in Cambridge (Cambridge battery services) that repaired lead acid batteries as long as they were the rubber cased variety with the top sealed in with bitumen,they would not repair the plastic cased ones that were coming in at the the time as they could not open or re seal them, from that bit of film it would seem you can, but the old elf n safety would have a fit if they saw that.

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