Re: bmw-digest V9 #789

[Desertmax@xxxxxxx]

In a message dated 99-01-05 16:31:08 EST, you write:

<< If the NiCads are subjected to a deep discharge they may not 
 recharge when the main battery is re-connected.  This is most common with 
 NiCads that have been in service for a number of years. >>

May I concur. Although I completely agree to your connect sequence, and that
NiCd technology suffers from the memory effect (= loosing capacity), a deep-
discharge (down to 0.6V per cell) actually *restores* the majority of the
original capacity.This is called "re-conditioning" and companies build
reconditioners for arrays of NiCd batteries. For those more technically
inclined, the memory effect is nothing but crystal growth in the electrolyte,
which reduces the effective surface area of the crystals. Deep discharge and
sometimes a high charge/discharge pulse current can break those larger
crystals, hence restoring capacity.
Credentials: I have been Product Manager for Battery Management IC's for the
last two years and will be working in Strategic Marketing for Power Management
Semiconductors.

Bert
looking out for a 32x iC
1500cc Vmax

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