mbeck@bnl.UUCP (Mark Becker) (12/15/84)
[For those that like to live dangerously...]
Several years ago I was busy zapping life into dead nicads. One of
cells proved stubborn so it was left on overnight recharge (*low current for
a D-sized cell*) and in the morning I found that the cell had exploded,
burying the casing into the wall about a foot from my head.
A few months later one of the things destructed in my hands while
zapping with a capacitor and a 15-volt supply.
The incidents bothered me enough and started taking safety pre-
cautions:
facemask - why bother getting that stuff on your face?
heavy gloves - ditto for hands.
metal box for zapping - (insulated with sticky paper)
if it explodes it might as well do it in there.
There were a lot of articles published in Popular Electronics on
how to "revive" dying carbon-zinc batteries... from fancy recharging
circuits to "punching holes in the case and soaking in salt-water".
Play it safe.
Mark Becker
UUCP: ...philabs!sbcs!bnl!mbeck
ARPA: mbeck@BNLdwl@hou4b.UUCP (D Levenson) (12/19/84)
A number of years ago, a Learjet aircraft was destroyed when its NiCad battery exploded in flight. Today, aircraft which use NiCads are required to have a safety system which prevents the thermal runaway that leads to this sort of an incident. These systems monitor the temperature in the battery compartment, the charge current, and the battery buss voltage. I don't know what algorithm they use in this monitoring, but they can shut down the charging system in time to prevent a catastrophy. -Dave Levenson AT&T-ISL, Holmdel