Fascinating video. [... ...]
Indeed interesting! A lot of work. In the USA parlance, it would be beyond even a re-built. It would be a re-manufactured battery since every part was attended to. It was so much work done there that if done in the USA, the cost of labor and parts/material would far exceed the price of a new battery.
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I have tried various rejuvenation methods and sometimes it works and most times it doesn't. Isn't worth the trouble.
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I am nearing that conclusion as well. Seeing some of the "so very simple to do" videos on youtube, I just want to see what can really be done.
I am arriving at: if trickle charge doesn't do it, that's it... almost
In my web-search based research, I found two
articles research papers showing pulse-charging works. Pulse-charging is beyond what I can do, but I found some "self-powered" pulser. Just clip it on the battery and powered by the battery, it send pulses back to the battery.
Per my research, these self-powered pulser pulses too slow and with too little power to do much. Since I do have 4 UPS/BoosterPac SLA's at hand, I'm going to try that and see if it does anything meaningful at all. Once I get it, I will start with my tiny 7AH battery. Right now, it self-discharges to 4V-5V quickly.
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.
it has low density so its not very destructive compared to outlawed things
It's the acid spray that makes it extra destructive, to eyes and things.
The exploded battery
G7PSK's posted has damage way beyond my expectation. I have been chewing on that. I want to understand it.
I am arriving at this theory:
Hydrogen may be a contributing factor, it may even be the trigger, but
hydrogen (ignition or not) is merely a contributor but not the main source of energy of the explosion. It is the steam pressure.
Pure sulfuric acid has a boiling point below 150 C. Battery acid is diluted so the boiling point is lower. Even 150 C is not hard to reach. Once it reach boiling point, boiling will turn all the liquid into gas rather quickly. True that as pressure increases, boiling point increases. But the energy injected into the system by the "charge" current can likely continue to push the temperature up enough to continue the boiling for some time. Plastic separator between cells is not good a thermo insulator. Neighboring cells would likely heat up and join the party. Between boiling and electrolysis, the pressure can build up rather high if there is no vent to release the pressure.
Steam has the ability to blow up steel-boilers in a steam engine, it sure has no difficulty creating damage commensurate with what is shown in
G7PSK's posted picture.
This is my theory and of course I don't know if I am right... My gut feel is hydrogen ignition is not enough. The scale of energy of steam matches my gut feel a little better.
EDIT:
1. Corrected the wrong quote. I inserted the wrong quote in the reply when I first saved.
2. Changed the wording "articles" to research papers. They were not merely someone writing an article for a magazine but serious research paper. One from IEEE, and another from 2017 IOE Graduate Conference.