Hydrogen (Re: solid state magnifier...accidentally...cool!)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>

Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Hollmike-at-aol-dot-com>

> Mattew,
>   The hydrogen is formed when charging the battery, so you shouldn't
> have to worry about that.

	With the cautionary note that Hydrogen can hang about a bit after the
	charger is shut off, or disconnected.

> The reason this occurs is because normally about two extra volts is
> applied by the charger to make it faster,

	In more detail:
	A '12v' battery is rather an oversimplification.  They run about
	13.? to 14.? at full charge, on charge...  Hydrogen
	production increases sharply as the cell approaches full charge,
	in fact this can be used to determine full charge.
  
> but the overvoltage tends to split some water molecules in a competing
>reaction.

	All the normal battery 'chemistry' having been reversed, there is
	'nowhere else' for the current to go.  except:

> I think the maintenance free batteries use a catylist (like
> platinum) to recombine the oxygen and hydrogen gases back to water
> in the headspace of the cells.

	Yep.

>  Don't quote me on that though.  That is the only way I can envision
> a way to eliminate the need to add water.

	Just so.  Such batteries are not Really Ultra Sealed:
	(in most cases) emergency vents are provided & stray Hydrogen can
	go bang.

> > Question - I guess that if I run my equipment of 12/24V lead acid
> > batteries, I'd need them a *long* way from any coils to stop any
> > hydrogen igniting.  Would on the other side of the walls of my
>>(steel) shed be adequate?

	Caution is good.  As noted Hydrogen normally shows up on
	full/over charge.  It dissipates rapidly on termination of charge,
	but not instantly...

	best
	dwp