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Ed Price
 
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Default NiCAD Memory Effect


"Chuck Tribolet" wrote in message
...
Because you leave them on simple trickle chargers long term, which causes

little
whisker crystals called dendrites to form inside the battery and short it
out internally. I get a heck of a lot of recharge cycles out my

rechargeables.
I use smart chargers that just about shutdown (go way below "trickle")

when
the battery is charged.

--
Chuck Tribolet



I believe that, as the crystalline area grows, it obscures the usable plate
area, which is what causes the "memory" effect. I read some recent research
(which I now can't find) where new cells were put through a careful charge
and then a deep discharge cycle. Then, the cells were deliberately
overcharged. Instant loss of capacity; the "memory" effect instantly
duplicated. OTOH, another group of new cells were put through many shallow
discharge cycles, with careful recharging. Result, no memory effect. Then,
with one overcharge cycle, the memory effect was now there.

Seems to confirm the concept of "memory", it's just that the culprit is the
charge profile, not the discharge portion. And that means that dumb
"trickle" chargers are really cell killers; we need to use smart chargers
exclusively.

I wonder if NiMH chemistry shows the same effect?

Ed
wb6wsn