Karl,
I did say very occassionally and I do not believe that NiCad packs will have an
issue with it, especially at the 1/10 C rate I also discussed.
I would not do this with NiMH and certainly not any Lithium chemistry. which
defnitely require balanced charging or regular balancing. I only use balanced
chargers on Lithium cells, but simple 1/10 C charging on everything else.
Complete discharging of NiCad (and only NiCad) packs is not an uncommon
practice in the RC world.
Jack
-------------- Original message from "Karl Vacek" <kvacek@ameritech.net>:
--------------
>
> > Also, NiCads, unlike many other batteries, have no issue and may benefit
> > from a very occassional, full and complete discharge.
> >
> > Jack
>
>
> This is a little off from Eric's dive light question, but...
>
> As an R/C pilot you can't mean that. You have a potentially lethal weapon,
> and an investment of hundreds (or thousands) of dollars flying around
> completely dependent upon the health of your radio batteries.
>
> If you're referring to completely discharging a nicad back as opposed to one
> individual cell, DO NOT do it.
>
> Maybe one or two complete discharges won't do any noticeable harm, but more
> than a few will begin to destroy the weakest cell in the pack. As the cells
> discharge, one reaches 0 volts first, and the current from the others
> flowing through it as they continue to discharge will reverse-charge that
> weakest cell, reversing its polarity. Then the second-weakest cell will
> reach 0 volts and reverse polarity, and so forth, till only one cell is left
> with any voltage.
>
> Do that a few times and you've ruined one or more cells and thus ruined the
> pack. That's why there are smart chargers and dischargers and
> expanded-scale voltmeters to monitor the state of charge and discharge of
> nicad cells and battery packs and exercise them as well.
>
> Karl
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