Re: Laptop battery Memory effect


Weinberger Hans wrote:
On 15 Mar 2006 12:33:43 -0800, "Leon" <leon_heller@xxxxxxxxxxx> wrote:


Weinberger Hans wrote:
On 15 Mar 2006 08:43:26 -0800, "Leon" <leon_heller@xxxxxxxxxxx> wrote:


Dan H wrote:
Weinberger Hans (Nospam) wrote:
Hello everybody.
I just changed my Laptop battery pack as the older battery pack would
recharge for around 5 minutes then stop. I could then use my computer
for a few minutes then it would switch off.
The curious thing is I after opening the laptop batteries they all
seem to be showing the right voltage. It seems that these NiMH are
showing memory effect. Does anybody know of a good way to discharge
them apart from a resistor. If a resistor what should its resistance
be.
The voltage reading inside the battery pack of each cell is around
1.27V.
Till later.
Hans

I don't believe NiMH batteries have memory effect. They are only good
for a certain number of charges. I suspect that is what has happened in
your case. The voltage will read good when charged but the amount of
energy stored is small.

And NiCds only exhibit a 'memory effect' in *very* rare circumstances,
mainly in satellite applications.

Leon
Nope.
Try
http://www.buchmann.ca/chap10-page1.asp
NiMh do exhibit "Memory effect".
Hans

That's hardly an authorative source. I'd rather go by what battery
manufacturers say, in their literature.

Leon

The author is the founder of Cadex a world leader in the design and
manufacture of battery analyzers and chargers, but if you believe more
in Battery manufacturers I'll give you 1 example, Sanyo a
manufacturer of Laptop NiMh cells
It says the Memory effect exists in NiMh cells over here
http://www.sanyo.com/batteries/pdfs/twicellT_E.pdf

Hans

I think they have it wrong, they are talking about ''voltage
depression' which is a totally different phenomenon. As I said, true
memory effect only occurs in very rare circumstances.

Leon

.

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