Test: revive old sealed lead acid batteries.

[lilshawn]

I took a bunch of picture and will update this post a little later after i get home for the day.
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EDIT: WARNING: imgur link (http://imgur.com/a/F0Dh8) links to an album of some photos that ark_ader is not allowed to click on because it contains unsafe practisces condoned by ark_ader such as: "Using utility knives" "Prying off the lids" and "Peering down the holes"

i'm sitting on a butt load of old sealed lead acid batteries (SLAB's) from old uninterruptable power supplies etc. so ive been doing some experimenting with some actually pretty positive results.

so, we have a couple dozen batteries of various sizes from UPS's. we used to have UPS's in our jukeboxes, but the servicing of them was a nightmare. so, just for shits and giggles earlier this week (slow at work) I decided to peel apart one of these old SLAB's and see what the deal was. none of these batteries have been touched in probably 2 years at least. some have swelled cells in them (definitely toasted), others look fine.

I grabbed the biggest one we had (12 volt 20 amp hours) and threw the voltmeter on it.

1.34 volts...lovely. This has got some potential. the first thing i noticed was that there was a vent hole in the top and it looked like i could pry the whole cover off...which of course I did with the first tool I could find.

to my surprise i found a bunch of rubber vent caps under the lid. SWEET! i noticed they where all dimpled down. i peeled the first cap off and was greeted with a sucking WOOOSH as air entered the cell. i peered down to hole to see nothing. no water, no electrlyte. nothing. just the top of the cell.

i looked in all the cells and they all looked the same. i peeled open a swelled up battery and looked in the cells and noted they where VERY different looking. The good cells had a nice white appearance (the fiber mat) while the swelled up cells where all brown and burnt looking.

I decided I would try and see if I could get some of these batteries going again.

i immediately went to google to find out how these SLAB's are constructed. turns out they soak fiberglas pads in electrolyte and wrap/construct the cells with this mat or gel holding the electrolyte in place. The ‘valve’ is a is actually just a small loosely fit rubber cap, and because the plastic plate always being over it, can push upwards to release any gas due to overcharging, but will get sucked back down once pressure is reduced. Since sealed lead acid batteries recombine the oxygen and hydrogen produced at either plate, it typically never needs to vent, and when venting does occur, the recombining results in a negative pressure.

the water eventually evaporates away and the dry cells crap out.

so logic dictates i must resoak the mat with water. so i grab a jug of distilled water (we have lots of it for our forklift battery)hook up the meter and proceed to use a 10cc syringe to soak the pads in all the cells. after damn near 60 cc's in each cell i could see the water no longer absorbing into the mat. i chose to fill them a little more (just over the top of the cell.) just as a test.

i could visibly see the voltage of the battery change as i added water to the cells.

i waited about 15 or 20 minutes for the voltage to stabilize. after I had topped everything off my final voltage had dropped to about 1.09 volts. i drew off a small sample of liquid to see if there was any trace of acid left. I dropped a drop of liquid into some baking soada and observed no reaction. Water. alright. a trickle charger (15 volts output at 1500mA) was then applied to the battery. i measured about 15.5 volts @ 250mA being actually applied to the battery at first. (great internal resistance) i watched carefully for a few hours and monitored the temperature. I didn't feel like my piddly A/C adapter was going to cause the battery to blow up but i left all the caps off just to be sure.

I let the battery charge overnight. by the afternoon of the next day the voltage output by the charger had dropped to 13.8 volts and was pumping almost 600mA. ahhh progress. I drew off another sample and tested it again with the baking soda. a great fizzy reaction was observed. Sulphuric acid. AWESOME!

I disconnected the charger and let the battery stand for an hour or so. I tested the voltage and it settled in at 12.54 volts.

I'm going to leave this battery stand over the weekend and measure the voltage again and see where it sits. if it holds i'll do some stress tests with it and see if it has any amps left in it.

The problem with these batteries is the float charging that is applied to them in the UPS causes them to dry out. Acid remains, giving a full or near-full voltage reading with no load, however as soon as the battery has a real load (ie: the UPS switches over to battery power), little current can be provided by the small surface area of actual active plate area in contact with a dried out cell, and the voltage drops to near zero.

i'd like to mention also that if you do attempt to revive a SLAB, or any battery for that fact...

if you begin charging and encounter anything odd out of what i've described here...immediately STOP what you are doing.

During this stage is when you should be monitoring for temperature increase, any hissing, or bubbling. a slightly increased temperature is to be expected...just slightly above cool metal, something like body temperature, anything warm or hot is not good, reduce charging current if you can or stop it completely.

If you do have a battery like this, it's best to to just toss it... You don't want one of these things blowing up on you.

[ark_ader]

if you begin charging and encounter anything odd out of what i've described here...immediately STOP what you are doing.

Oh really?   

Like fire or corrosive burns from leaking acid? 

[lilshawn]

well, people are stupid by nature. 

[ark_ader]

well, people are stupid by nature. 

Well remember that adults are not the only ones accessing the internet.  Personally I find your post rather upsetting, as it could encourage a child to experiment with dead batteries.  There are warning signs on all batteries about not recharging them, etc - then I see your post encouraging the acts.

The stupid you are referring to is the child who knows no better.  And possible you for posting such information without thinking.   

I think the Mods need to add an extra "what not to post" to deter posts like yours that can lead to injury and possible death..   

[Ken Layton]

You tube has some excellent videos posted on the topic of reviving sealed lead acid batteries. Here is one of them:



Here is the special charger talked about in the video:

http://screwdecaf.cx/dapimp.html

[ed12]

i found not a thing wrong with the post
it was most in-formative indeed
the warring DO NOT DO THIS IF..
was prof postive to me the nick was telling ppl what could happen :IF:
if u found STUPID offince...
then u live on higher moral ground then i ever want to touch..

ed

[ark_ader]

You tube has some excellent videos posted on the topic of reviving sealed lead acid batteries.

True.  But if I was a parent I could have controls installed to prevent my kids accessing Youtube and or related material.  There are some good vids for all kinds of stuff to get into trouble, but this is an arcade gaming site and I would not even think that such material would be available that could harm a child or "stupid adult".  I would have a hard time blocking this site unless I was having to do it manually.

Its not the content that is the problem, it is the audience, that is why I think there should be an area like PnR that is restricted to over 17s, where you could post such content and tube capping (another accident waiting to happen) without recourse.

But good point Ken!

Nice video.  Like the bit about the razor blade and watching it fly off, and the not wearing any protective gear.  Something we keep asking people to do  after seeing so many horrible accidents. 

[DaOld Man]

Like the bit about the razor blade and watching it fly off, and the not wearing any protective gear.  Something we keep asking people to do  after seeing so many horrible accidents.

Well he was wearing sunglasses, which would provide a fairly decent eye protection. But I did cringe seeing him use that razor blade without wearing some thick gloves (leather is best). One slip of the hand and he could easily need stitches.
Also it should be mentioned that lead acid batteries give off hydrogen gas when charging. This is highly explosive and any flame or spark (attaching or removing current carrying conductors) could possibly ignite the gas.
Also it should be mentioned that because of the gas, this needs to be done in open air. He was doing it outside, but I don't remember him telling the audience why he was outside.

[pbj]

[lilshawn]

great, now you've made me roll my eyes so hard i've detached my retinas and now i'm blind. thanks. 

[ark_ader]

great, now you've made me roll my eyes so hard i've detached my retinas and now i'm blind. thanks. 

But you still have fingers and possible Dragon Dictate, so we might still have a problem here with stupid adults and children.

[SavannahLion]

Ark, I see this as being not much different than the other things we do here and the danger is about the same.

A child can easily read about the high voltage wiring required for cabs. How many posts are here modifying power strips, power cables, wiring isolation transformers? Did we have a discussion on using the correct gauge wire? Insulation?

CRT, safe if they're understood. How often do we talk about the flyback or The Suction Cup on the back?

How about that FL ballast? Didn't someone try to wire their LED strip into one?

How about proper lifting on the heavy cabs? Proper weight distribution on the truck? Tie downs?

Hot solder? Hot glue? How many of our members still sport burn scars from hot whatever.

Table saw safety? Router? Drill? What about when someone hacks their own power tool?

toxic glues and toxic solvents. How about the wood we use? Does everyone really use masks when cutting MDF?

my point is that this hobby encounters a reasonable share of danger and we, as a forum, don't always address each and every danger. We're not here to babysit, we're here to generate information about our hobby.

[ark_ader]

Ark, I see this as being not much different than the other things we do here and the danger is about the same.

A child can easily read about the high voltage wiring required for cabs. How many posts are here modifying power strips, power cables, wiring isolation transformers? Did we have a discussion on using the correct gauge wire? Insulation?

CRT, safe if they're understood. How often do we talk about the flyback or The Suction Cup on the back?

How about that FL ballast? Didn't someone try to wire their LED strip into one?

How about proper lifting on the heavy cabs? Proper weight distribution on the truck? Tie downs?

Hot solder? Hot glue? How many of our members still sport burn scars from hot whatever.

Table saw safety? Router? Drill? What about when someone hacks their own power tool?

toxic glues and toxic solvents. How about the wood we use? Does everyone really use masks when cutting MDF?

my point is that this hobby encounters a reasonable share of danger and we, as a forum, don't always address each and every danger. We're not here to babysit, we're here to generate information about our hobby.

Agreed, I am all for all of your above points even if some are extreme, but recharging dead batteries is very dangerous and should not be undertaken, in any circumstances.  Go ask Duracell or Eveready if they endorse this behaviour?  They won't due to the dangers.



I don't care how much you sugar coat it, recharging dead batteries is dangerous and should not be taken lightly. 

[ed12]

this whole thing is about control and over-site
after 45 years in this business..i have my grandchildern asking me to teach them,
i think great..then in kicks the basic >RULES<..do not touch here or there
until i am happy u know what u are doing with this or that..
ie >control<,and >over-site<...
i never leave them alone in my shop..thats not  just them..i never leave a coustmer alone in my shop..and they know the basics..again control and over-site

ed

[SavannahLion]

All of my examples above are derived from posts or discussions on this forum from what I can recollect. A couple are direct experiences of my own (never use hot glue or solder anything in your underwear. It's decidedly painful.  )

Oh sure, I agree that it is dangerous. I also agree it should never be taken lightly. I just don't agree with you that such an endeavor should never be taken.

We, as a society, have long been in a ravine void of any independence or intelligent thought stemming from those who tell us that any sort of risk are grounds for never doing anything. In general, so many people have long accepted the answer of, "you'll shoot your eye out!" that too many people are unwilling  to do much of anything interesting. Or worse, ask why....

I take what Duracell and Energizer with a grain of salt, after all, recharging your battery is going to hit their bottom line.  Not that I encourage that particular practice.

As for that video, A better point would be, do your recharging outside? Away from any sparks? Or perhaps, try not to do any metal work near a recharging a dead battery? I would take that video with a huge dose of salt. He puts the dummy in a situation that one shouldn't find one self in anyways, then suggests buying (renting?) a sealed shed to store said batteries?

this whole thing is about control and over-site
after 45 years in this business..i have my grandchildern asking me to teach them,
i think great..then in kicks the basic >RULES<..do not touch here or there
until i am happy u know what u are doing with this or that..
ie >control<,and >over-site<...
i never leave them alone in my shop..thats not  just them..i never leave a coustmer alone in my shop..and they know the basics..again control and over-site

ed

My sheds, shop and garage have rules that will met out the swiftest and most severe punishment if they're broken. In the house, I hold my kids responsible for their own actions. In the shop, I hold them responsible for the actions of themselves and everyone else around them. The idea of being grounded for a month because big sister was goofing off is a damn good deterrent. 

[ed12]

exactley
it is called common sense....

like your ref to the high-voltage lead..
welp there must be a way.? but what is it exactley ?
ground here stick there wait, for the >zap< push and pull
wa la anode is off and u did not get a shock..
i totaly agree with saftey..but this must be taught.
it dose not come natural

ed

[lilshawn]

some disclaimer is better than no disclaimer. 

I'm sure SOMEBODY...would have jumped down my neck if I hadn't put anything at all.

[ark_ader]

some disclaimer is better than no disclaimer. 

I'm sure SOMEBODY...would have jumped down my neck if I hadn't put anything at all.

Kids do not listen to disclaimers or warnings and those who put up videos do do at their own peril. If a child gets hurt or dies from the actions of a you tube video we all know it is going to make the headlines and those responsible will get punished.

That is not my point.  My point is the presentation of recharging dead batteries in an arcade controls forum.  Other than UPS which I can count on one hand how many people go out and buy one for an arcade cabinet let alone a home PC.  The norm lately being laptop and tablet use.  I do not see any use from your original post or videos contained in this thread (mine excluded) which could lead to acid injury, explosion or worse.

I would not recharge a dead battery (exception being rechargeable batteries) for UPS use or any other enterprise.  I would simply go out and buy another UPS with warranty.  It is so frightening to know that you people are so irresponsible to think that recharging dead acid batteries is productive.

Does Saint think that recharging dead acid batteries is safe for general consumption on this board? 

I am very serious about this. 

[lilshawn]

That is not my point.  My point is the presentation of recharging dead batteries in an arcade controls forum.

this would be why it's filed under the EVERYTHING ELSE forum

I would not recharge a dead battery (exception being rechargeable batteries) for UPS use or any other enterprise.  I would simply go out and buy another UPS with warranty.

don't then. nobody is twisting your arm.

It is so frightening to know that you people are so irresponsible to think that recharging dead acid batteries is productive.

which battery company did you work for again, I forget...

Does Saint think that recharging dead acid batteries is safe for general consumption on this board? 

I'm sure he, like most people in the world, take things they read on the internet with a "grain of salt". Of course I'm sure if you did that you'd have an unusually high sodium level. I'm not telling you that you must do this. I'm not forcing you to recycle. I'm not peer pressuring you into doing something you don't want to do.

I take it you never seen my other post where I used DANGEROUS HIGH VOLTAGES and hammers and wire and made a spot welder out of a microwave transformer. You may have been on vacation... here's a link to it.

]http://forum.arcadecontrols.com/index.php/topic,130330.msg1333493.html#msg1333493]

Now I'm SURE you've noticed we all here have posted horror stories on BYOAC about how we've blown our hands off and died of electrocution and heart attacks and unattractiveness to the opposite sex.

EDIT: fixed borked link

[SavannahLion]

Geez ark, I expect all sorts of pigheadedness from others but you're really taking the cake. If we only allowed posts relevant to "the norm" this forum would be pretty empty.

So my projects are outside the norm because I do not use laptops or tablets in my cabs? Or because I don't buy my controller boards from Randy or Andy? Or maybe I'm outside the norm because I like, and still use, CRTs in the bulk of my cabs?

You want safety? Then Saint should get rid of all the high voltage posts or the soldering posts. Might as well get rid of all the woodworking posts that deal with table saws because, you know, kids don't read warnings. ---steaming pile of meadow muffin--- might as well shut the entire forum down because of all the paint huffing that goes on. 

Leave your warnings but don't try to scrub the lesson.

[ark_ader]

Is my objection related to any of those subjects you have mentioned SL?  All I am saying is that recharging dead batteries is dangerous, and should be disposed of properly.  Posting such material which a child can read and practice, possibly be injured is not informative reading.  Sure nobody likes to be told they are irresponsible.  Yet there should be some form of common sense involved and responsibility. 

I am sure that all the parents of children that were burned, blinded or killed due to batteries would agree with your stance.

I have yet to hear from Saint on this matter.  Let's see what his impression of the situation is.

Fair enough? 

[DaOld Man]

This thread reminds me of my childhood.
When I was around 10-11 years old, we rented an old house that had a bunch of calcium carbide stored in the basement. Of course I had to find out what was in those barrels.
Calcium carbide  is the blue crystal stuff that when mixed with water gives off a flammable gas (acetylene). It was commonly used in miner lanterns to light the way.
Anyhoo, I read up on the stuff from books at the library (didn't have computers, let alone internet.)
So the experiments began.
I made batteries (a "crows foot" comes to mind).
I later experimented with sulphuric acid to make more batteries and experimented with making hydrogen gas by mixing the acid with zinc from old flashlight batteries. This was real cool for making soap bubbles that floated away, not to mention making water droplets with a controlled micro explosion. (Much to the amazement of my friends and siblings)
And the only safety equipment I used were my prescription glasses.
Ah the memories.
(It's a wonder I lived to become DaOld Man I am.)

[SavannahLion]

Ark, I mention those things because your objections hold virtually no merit. Many of the things I mentioned can and do kill children (and a few adults) every year. Yet no one (at least not that I ever noted) ever objected to that information here on the forum.

Safety is a concern, always is. I am not encouraging a person to take innecessary risks with any endeavor. What I absolutely refuse is to allow you, or anyone else, to censor knowledge about our world under a false guise of safety. That is absolute folly.

[ark_ader]

If you do have a battery like this, it's best to to just toss it... You don't want one of these things blowing up on you.

That is appreciated.   Thanks 

[JDFan]

If you do have a battery like this, it's best to to just toss it... You don't want one of these things blowing up on you.

That is appreciated.   Thanks 

Actually all rechargeable batteries (except for rechargeable Alkaline cells) need to be disposed of at a collection point such as Best Buy Stores, and office supply stores such as Staples or Office Depot. The batteries contain toxic materials and should not be thrown in the trash. This also applies to Lithium Cells and Mercury batteries. Batteries are highly toxic, and what you dump today, you drink in 50 years.

For someone so concerned about the safety of others I'm surprised you would advocate just tossing them out which creates more of a safety problem than someone trying to revive them as outlined in this thread !!

[lilshawn]

i'm sort of getting the impression that ark_ader believes these batteries weren't meant to be recharged.

these batteries are really no different than the lead acid battery in your car/truck/motorhome down by the river.

the only difference is that the acid is contained in absorbent mats that hold it in place...allowing the battery to be positioned in any direction you see fit, where your car battery would leak all over the place. optima batteries are the sealed lead acid battery of the car world

after you start your car, the alternator dumps 100 some odd amps into the electrical system...some to be used by the car, the rest to recharge the battery.

now I'm no scientist here, but i just know ark_ader might freak out realizing now he's been driving down the road recharging a battery. 

[ark_ader]

If you do have a battery like this, it's best to to just toss it... You don't want one of these things blowing up on you.

That is appreciated.   Thanks 

Actually all rechargeable batteries (except for rechargeable Alkaline cells) need to be disposed of at a collection point such as Best Buy Stores, and office supply stores such as Staples or Office Depot. The batteries contain toxic materials and should not be thrown in the trash. This also applies to Lithium Cells and Mercury batteries. Batteries are highly toxic, and what you dump today, you drink in 50 years.

For someone so concerned about the safety of others I'm surprised you would advocate just tossing them out which creates more of a safety problem than someone trying to revive them as outlined in this thread !!

Dispose of them responsibly, but people do put AA type batteries in the trash every day.  If you look at this post you would understand that I am well versed in RoHS and WEEE standards.  Nice try.

i'm sort of getting the impression that ark_ader believes these batteries weren't meant to be recharged.

these batteries are really no different than the lead acid battery in your car/truck/motorhome down by the river.

the only difference is that the acid is contained in absorbent mats that hold it in place...allowing the battery to be positioned in any direction you see fit, where your car battery would leak all over the place. optima batteries are the sealed lead acid battery of the car world

after you start your car, the alternator dumps 100 some odd amps into the electrical system...some to be used by the car, the rest to recharge the battery.

now I'm no scientist here, but i just know ark_ader might freak out realizing now he's been driving down the road recharging a battery. 

Don't be a child, I thought I was conversing with an adult all this time.   

Charging of batteries should be done in a location that is safe and by specially trained professionals.  Not you.  To be completely honest, I am very concerned by your apparent lack of responsibility.  Only to be advised do you append your ways.  An old dead battery should be disposed of responsibly and your purchase of a new battery help others in so many diffrent ways. 

I know you and SL are trolling me, but it is fine to temporarily sink to your level, if only briefly. 

[ed12]

ark_ader
so u are posting working with these is a bad ass move
welp what about working with nicrtic acid ?
how about your car battery ?
to state just get rid of it and get another is blant disragaurd on so many levels
it would take 2 pages just for u to read it...u ever have a lead acid battery re-fuled
so it will charge again? or did u just dith it and buy a new 1 ??
welp these re-charges are dumping the sulpric acid out and pouring in new...
guess what ? THEY GET PAID TO DO IT...
kinda of blows your theroys out the door eh.?
how about crt-rebuilders..? working with vacum's,and have to :de-evvacke a tube first..:,gee let me see vacuom-30psi,small glass,yet again THEY ARE PAID FOR IT...
i could go on..cover your eyes
if u do not like the thread..please step out of it

ed

[ark_ader]

ark_ader
so u are posting working with these is a bad ass move
welp what about working with nicrtic acid ?
how about your car battery ?
to state just get rid of it and get another is blant disragaurd on so many levels
it would take 2 pages just for u to read it...u ever have a lead acid battery re-fuled
so it will charge again? or did u just dith it and buy a new 1 ??
welp these re-charges are dumping the sulpric acid out and pouring in new...
guess what ? THEY GET PAID TO DO IT...
kinda of blows your theroys out the door eh.?
how about crt-rebuilders..? working with vacum's,and have to :de-evvacke a tube first..:,gee let me see vacuom-30psi,small glass,yet again THEY ARE PAID FOR IT...
i could go on..cover your eyes
if u do not like the thread..please step out of it

ed

Sorry buddy I cannot understand what you have written there (with all due respect) can you edit that for me so I can reply? 

[ed12]

what i stated in short
we re-build all sort's of thing's
they all come with there own grab bag of dangers
there are ppl PAID to do just such
this is not new news
if u are worried some :child: is going to do this
then write a letter to youtube/acradecontrols/interesting-devices/slashdot.com,
and ask them to stop doing it..about that simple
if not stop looking at the thread
again about that simple

ed

[lilshawn]

Charging of batteries should be done in a location that is safe and by specially trained professionals.  Not you. 

Describe a safe location and who is a specially trained (battery charging) professional.

I hardly think a metal can powered by flammable fuel going 100 miles an hour down the interstate a "safe" place to charge a battery. but, there it is.

What about the millions of people a day who operate said metal cans? I hardly consider them "professional battery rechargers". (well perhaps some of those people ARE professional battery rechargers.) 

I would think charging on a bench with constant monitoring, checking, and supervision with proper equipment is a much safer situation than flying down the highway, where nobody is watching, monitoring, OR checking.

[ark_ader]

what i stated in short
we re-build all sort's of thing's
they all come with there own grab bag of dangers
there are ppl PAID to do just such
this is not new news
if u are worried some :child: is going to do this
then write a letter to youtube/acradecontrols/interesting-devices/slashdot.com,
and ask them to stop doing it..about that simple
if not stop looking at the thread
again about that simple

ed

You are absolutely correct there (and thanks for the edit)  and I would not think of kids slicing their legs off with electrical saws, burning their fingers (my trick) with a soldering iron, or anything else that would at least leave a small scar (which is life) heck I have lots of war wounds I am paying for that I achieved in my youth.

I do not want to censor information, but I think we have a moral obligation to think before we post in a forum that is gaming orientated.  Obviously we post things (  ) that would upset some lurker some time, but there are topics that should have a degree of sense when kids do visit this site thinking it is cool to open dad's car battery and fix it for him and end up getting blinded, seriously sliced, etc.

If the topic is unsafe, do what Ken did and post a youtube link with a disclaimer and keep it low key.  It would be up to the parent to keep little timmy or sally away from adult material.  Personally I would not open a car battery and try to resurrect it.  I would trade it in for a new one.

That is my point.  Keep dangerous topics that can cause serious harm away in a arcade related forum and not in EE as EE is warm and fuzzies right?  I have had no Mods warn me on this or correct me either so I must be right (as usual).

Or post it on your own web site and link into it.


Now to slip into  lilshawn tiny mind for a moment....

Describe a safe location and who is a specially trained (battery charging) professional.

Car Mechanic/Garage  This image should make it easier for you to understand or relate to:

I hardly think a metal can powered by flammable fuel going 100 miles an hour down the interstate a "safe" place to charge a battery. but, there it is.

   Love the comedy.

What about the millions of people a day who operate said metal cans? I hardly consider them "professional battery rechargers". (well perhaps some of those people ARE professional battery rechargers.)

I would think charging on a bench with constant monitoring, checking, and supervision with proper equipment is a much safer situation than flying down the highway, where nobody is watching, monitoring, OR checking.

Please do not go full retard.  We don't need that here.

[ed12]

dude i got so many burns,nicks
that at times i even fear doing electronic work
working on 450volt eq..is not a thing i would love to do with out firt knowning why
point is i learned..and have ran a very good service trade..
and i agree somethings should not be posted on youetube
but here..no unless there is a troll looking at how to make a bomb,then that will
get my goat..but what the nick is doing will futher your know..like i stated
yes u can re-charge ceritan types of bats.,if u know the way..
lord most ppl do not even get the fact u CAN NOT STORE A LEAD ACID BATTERY ON  A CONCERTE FLOOR.
the reason is so simple that when u explain it to them they go wtf....
and these are 40's and up ppl..go fig

ed

[ark_ader]

I remember the time (25 years ago) I worked on an external processing box and it had a 240v transformer that wasn't grounded properly.

The knob technician who started the assembly (not me) and  the installation on this unit had plugged it into a non earthed socket and somehow decided to ground it to the outer casing.  So when it came time to install it on to a bracket, yours truly got a nasty surprise.  When I woke up I couldn't move my arm, and to the right of my head was a screwdriver embedded in the brick wall behind me with my hand still gripping the handle.

I still cannot extend my arm above my head properly.  I test everything before working on any project, in case some idiot wired it up wrong.

So I agree that working in a shop (especially with high voltage) has some hidden danger. 

Remember though 12V can kill you just as quickly as 240V. 

[ed12]

oh my god can i hear u clearly
i was once doing a reno on a restruant
the kitchen panel had to taken out..
was working as a sub under the master
i asked him 4 times is this panel disconnted..so i could un-hook the 3 phase
he siad yes 4 times..with a snarl..i went ok.thank-you
unhooked all the breakers etc
then came the fun...1 phase out..marott off
2nd phase off..same..thinking we are cooking now
3rd phase and the flash blew my eye-lashes off..its a very lovely blue color,and bright,thought as i got up ....from the floor 25 feet away from the panel,
welp to take things in stride my large straight screwdriver missed his head by 1/2"
as i through it at him..true story
turns out  they had never un-hooked the panel >mains<..
moral like wood measure 2-x cut 1-x
if u are working with hazred rem the basic rules
never take anyones word for it

ed

[danny_galaga]

My only thought about this is that is there much value in it? Lead acid batteries have two sets of plates- lead and lead sulphate. Since one becomes the other to charge and vice versa to discharge, over time they become misshapen and inefficient. If all that's happened is the battery has dried out, I guess it could be revived. But the distortion and change of composition over time is pretty much irreversible. It really doesn't seem to be worth the risk...

I mostly see what Ark is saying, except that I don't see how 12V will kill you (via electrocution anyway).

[ark_ader]

I mostly see what Ark is saying, except that I don't see how 12V will kill you (via electrocution anyway).

It helps if you stand in water, but not on your head.   

[lilshawn]

I don't claim to know of all things electrical, but I do know a 12 volt car battery does not have the capability (electrically*) of killing you. otherwise you would die if you touched the posts of the battery.

* of course if you hacked open each side of your head and jammed jumper cables in the open wound so current was flowing directly across your brain I'm sure it could...I'm simply talking about normally encountered circumstances.

people die from electricity mainly because:

a) the heart stops pumping. (defibulation)
b) your diaphragm stops moving air in and out of your lungs and you suffocate.

the actual act of electrocution is quite survivable provided you can maintain blood flow and respiration...2 REALLY important things to the human body needs to continue living.

both of these acts are autonomous in nature, when you disrupt it, sometimes it doesn't continue.

Now, I've got a multimeter in front of me, so I'll measure the resistance between my hands. It reads about 1MOhm or 1 million ohms. It varies significantly depending on how hard I squeeze the probes and how moist my fingers are etc. If I was to put my hands on the terminals of a 12 volt car battery, the current flowing through my body would be about 12 microamps, not much. If I was to put my hands on the terminals of any 12 volt battery pack, the current would still be about 12 microamps. The current is the same because the resistance of my hands is millions of times greater than the internal resistance of the batteries. It doesn't matter that the car battery can deliver 800 amps, or the battery pack 1 amp. my hands will only pull 12 microamps out of the battery.

A 120 volt wall outlet is a different story. If we were to apply Ohms law on a 120 volt circuit, about 120 microamps should flow through your body. That's still not enough to do much harm, but people are often killed by household circuits. The reason is that your skin resistance is not linear. At about 50 volts or so, the resistance of your skin drops dramatically. The current flowing through your body may not be limited by skin resistance, but by the ability of the voltage source to deliver current. In fact, you can feel a slight tingle at voltages as low as 24 volts. (Thank you pinball machine, for informing me of that fact)

This is also why in my rediculous MOT welder you can safely touch the leads. Even though there is 2000 amps of power there to be had, it's only putting out somewhere around 2 volts. (2 microamps)

So what's the answer? Is it the volts or the amps? Basically, it's both. Low voltage (less than 50 volts) won't hurt you because of high skin resistance. High voltage can cause a heart attack if the source can deliver moderate current (100 milliamps). High voltage coupled with the availability of high current (like power lines) can result in lethal shock as well as serious burns and tissue damage. Electricity is an inanimate beast without compassion or remorse. It must be respected at all times.

[ed12]

nice reply..nice indeed
even tough u did leave a few things out.u nailed it
1 thing we most never do is touch 120 volts with bare feet on concrete
reason is simple u are now the :dead: ground..
hence the reason canada went to 3 wire power system..dead ground is now green.
not that i have seen some ppl try it..but is but there..which falls under u can not fix stupied..

ed

[lilshawn]

Yes, there are parts of a 110 circuit you can safely touch, and others you can't. I don't trust anybody's wiring enough (like mixing up the live and neutral) to attempt it, so I don't.