charging ni-mh batteries , question

[paul.g7izx]

HELLO THERE .
I have a Question , Ref: charging Ni-Mh
I have done a little bit of research on this subject ,
but still haven't found out what I needed to know

I Normally charge my > Nicads < on a Power-supply
which has a fully variable Current ( or Current Limiting ) if you like
and fully variable Voltage Output & its output is DC & Fully Smooth
When viewed on a scope . I fully understand the maths , Volts , mAh and
time , = charge times etc

But my actual question is should I be able to charge my 2000Mah
Ni-Mi ? With my Power supply as described above .

Or should it have a little Ripple etc ?

( As I have read that most modern charge have 2 settings on them
one switch position is to charge Ni-cads the other for Ni-Mh
, ** But it was Suggested that it not only does it changes the charge
current
it increases or decrease the time the batteries are charged and uses the
auto cut-off ,
It some-how also prevents hydrogen build-up within the cells while charging
all of which is fully understandable , but the bit I don't understand is
it states that it also changes the method of charging
** Now what the last bit referes to I don't know maybe it means more or less
ripple.
when charging )

any ideas welcome

thanks de Paul

 

[David Harmon]

On Sat, 19 Jul 2003 21:23:08 +0100 in sci.electronics.basics,
"paul.g7izx" <paul.g7izx@ntlworld.com> wrote:

But my actual question is should I be able to charge my 2000Mah
Ni-Mi ? With my Power supply as described above .

Or should it have a little Ripple etc ?

The most important thing about charging a battery is knowing when to
stop. A little ripple in the supply will not harm the battery, and it
will not help the battery. But it may make it much harder to know when
to stop charging, if you are using a voltage sensing method.

A large ripple may cause extra heating of the battery, not good.

it states that it also changes the method of charging
** Now what the last bit referes to I don't know maybe it means more
or less ripple. when charging )

The last bit means it uses a different method to decide when to stop.