Re: Speaking of car batteries

"Blue Heeler" <woof@[EMAIL PROTECTED]
> wrote in message 
news:63a3svF270t4hU1@[EMAIL PROTECTED]
> Lu R wrote:
>
>> I once had to recharge a flat  beaurepaire battery and it went
>> reverse charge on me! Put it back in the car and it blew my fuses.
>> Took it back and they seemed to not believe me til they checked the
>> charge and then tried to blame me for reverse charging it but no
>> freakin way did I swap poles on that charger. Has anyone ever had
>> this experience?
>
> You imagined it.
>
> NiFe cells can do the polarity reversal thing under certain conditions,
> but no NiFe cell has ever been used in a car, and Beaurepaire have
> *never* made or sold NiFe cells.

quote from http://www.europulse.com/eng/technology/index.shtml

Another phenomenon in motive power applications is the "dead cell". During
a
very deep discharge cycle, some plates within a cell will reverse
polarity.
During recharge these cells must first receive energy to return to a
"zero"
state, and then begin recharging once proper polarity is achieved. The
surrounding cells have efficiently recharged, as they did not first have
to
return to a zero state. However the cells with reversed polarity plates
depress battery voltage, causing the charger to provide strong current.
The
effect is severe boiling of the fully
charged cells and potentially mechanical damage to the battery.