[rescue] I'm not an EE Q - clarification

[Kris Kirby]

On Thu, 18 Jul 2002, Tim H. wrote:
> umm, what does the charge capacity of the battery have to do with
> anything?  48V of AA cells will hit just as hard, actually, harder if
> you manage to become a dead short, because the internal resistance of
> the lead acid cells is higher.

Until the battery's internal resistance catches up, a gell cell can dump
an insane amounts of current. 48V x 50A = 2400W = crispy fried in your own
juices. All it takes is a blink of an eye, and gell-cells are best known
for short term, high current capabilities -- car batteries take this to an
extreme, however.

> Just follow standard live electric rules, keep one hand out of the way,
> don't stand in a puddle.  Electricity is not any more intrinsically
> dangerous than a loaded gun, just follow the rules.  Being scared of it
> makes you twitchy, and more likely to light yourself up.

Well, let's not forget that I *did* rewire the 24V 33AH `array' on my UPS
this evening, so I think I'm sharp. :) No twitchy....

> Electricity will not hurt you, but you may hurt yourself with
> electricity.

Yeah, but pissing yourself is just a warm, wet sensation if you drop a
screwdriver onto buss bars[1].

[1]: Quite a few large installations have a few screwdrivers welded to the
    buss bars -- nothing in between!

--
Kris Kirby, KE4AHR  <kris at nospam.catonic.net>  TGIFreeBSD IM: 'KrisBSD'
"Everytime my faith in humanity has been tested...humanity has failed."