T&L Publications

I'm trying to understand the chemistry of lead acid batteries.<p>If I removed a good cell from a 12V deep cycle battery and placed it in 10 gallons of new sulfuric acid and water with proper proportions.<p>If that cell had been fully charged before the transfer to the 10 gallon tank.<p>What would go wrong if I operated that cell to full discharge and then tried to recharge it?<p>My current reading of the discharge and charge equations indicates that the cell could be fully discharged and then fully charged with no noticeable difference other than electrolyte density measurements could no longer be used to determine percent of charge since there would still be plenty of sulfuric acid dissociated ions present and density of the 10 gallons will not change much.<p>On the other hand, I wonder if the discharge reaction would continue until all the lead and lead oxide plate area at the atomic level was plated with lead sulfate.<p>If lead sulfate is an insulator, then it might not be possible to get charging started again.<p>Anyone care to venture an opinion and reason for it?<p>Thanks in advance for any insights you can give as to what the physical meaning of full discharge is if it is not complete insulating plating of the lead substrate with lead sulfate.<p>Or the physical meaning or situation associated with 50 percent discharge.
[ November 16, 2004: Message edited by: windmiller ]<p>[ November 16, 2004: Message edited by: windmiller ]</p>

You nailed it. When Lead sulphate is exposed to oxygen it hardens. The hardened lead sulphate shields the plate underneath, you have less surface area, the battery capacity diminishes.<p>This is why you want to recharge a battery ASAP when it gets run down.<p>Here's a post by a guy who knows a lot of things about a lot of things...<p>http://www.phrannie.org/battery.html

checked out web site ..lots of misinformation and incomplete information

joe

I don't know. I read about 1/3 of the way through and it looked pretty good to me. Maybe it's my own inexpertise? Only things I objected to in this 1/3 sample were:<p>"It's like 'making a blivet' (a blivet is 10 pounds of poop in a 5 pound bag). You have to force more electricity into a battery than it would like to accept..."<p>A blivet is actually a thing you can't pick up with a vacuum cleaner and have to pick up with your fingers. <p>And:
"Amperes are the measure of actual power available."<p>Probably should read something like: "Amperes are an indirect measure of actual energy available," but the author goes on and explains it adequately.<p>What misinformation/incomplete information did you find? Just curious.

Thanks gents:<p>The website has a lot of good practical information that I have use for.<p>Just now, though, I'm trying to get a feel for what goes on at the atomic level inside a battery.<p>For instance, the website went into measuring "resting voltage" rather better than I've seen anywhere else. He says a 24 hour wait after the last charge or discharge incident is better than 12 hours.<p>What I would like to understand is the nature of what goes on during this resting period and why the extremely long "time constant".

The battery charges up when the substance of the battery is re-polerized or infused with a new memory. However like alkaline ones sometimes explode and leak the fresh infusion is a little off or different from the original. This could cause a clash resulting in ruining the battery or a improvement. An improvement is like mixing alkaline with nickel metal hydride the alkaline becomes a ni-cad. I don't work with lead acid but if you want to switch to nickel metal hydride you could check out my web site at http://www.geocities.com/tired94302/<p>[ December 13, 2004: Message edited by: kehearbear ]</p>