As memory effect was widely admitted in the battery and portable device
industrial, I have never doubt about its existence (in Ni-cd and dry
Lead-acid). Being work in laptop manufacturing industry in early 80 to 90, I
had read a lots of such documents.
Overcharging Ni-cd generally will not damage it unless it is overcharged at
a high rate >0.5C for hours or >0.2C for a long time. Many of the them are
ok to charge for a long time at <0.1C. The battery life (charging cycle) may
slightly reduced under severe charging condition but damage will not
immediately happen.
Ni-MH and Li-ion battery are very different, Ni-MH does not like overcharge
and Li-ion even worse. At the mean time Li-ion does not like over discharge
too so there is always circuit built into them to stop discharge when
battery level is low.
C.H.Ling
----- Original Message -----
From: "Moose" <olymoose@xxxxxxxxx>
> ---------------------------
> It was my understanding that the "memory effect" with NiCads was in
> general no such thing.
>
> The symptoms are clear enough, reduced capacity that may be, largely,
> restored through a regimen of at least a couple of deep discharges and
> recharges.
>
> I read a tech paper somewhere that claimed this was mostly a result of
> long term overcharging. It said there was indeed a memory effect, but
> that it was rather small. It said the more common and troublesome effect
> that everybody was calling memory effect was in fact a result of dumb
> chargers that maintained a charging voltage and/or current all the time,
> forcing the battery into an odd, overcharged condition.
>
> My own limited experience has been that cheap items with dumb trickle
> chargers do indeed have that happen, and in fact eventually kill
> batteries that have hardly been used. A RS safety lantern that comes on
> when the power goes off comes to mind. The batteries eventually died
> with essentially no use. When I replaced them (solder tab type), I found
> there was no charging circuit at all, just poser from a simple wall wart
> always on the batteries.
>
> On the other hand is my Makita drills of many years provenance. the
> charger is large and clearly has some circuitry in it. When a used
> battery is attached, the red light goes on, then goes out when the
> charge is complete. I believe, although I can't swear to it, that the
> light occasionally goes on for a time again. In any case, A battery may
> be on the charger for months and have full capacity, whether used
> lightly or heavily before.
>
> Moose
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|