Re: Laptop battery Memory effect

On 16 Mar 2006 06:17:29 -0800, "Leon" <leon_heller@xxxxxxxxxxx> wrote:


Weinberger Hans wrote:
On 15 Mar 2006 15:13:45 -0800, "Leon" <leon_heller@xxxxxxxxxxx> wrote:


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 woul
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

LMAO .
First a founder of a worldwide leading Battery charger /analyzer
company is considered dumb by you, now Sanyo Corporation do not
understand what the memory effect is.

Thats actually bad quality trolling.

exskimos

This is what Saft says:

Do nickel-cadmium batteries for telecoms exhibit the memory effect ?

The memory effect is a reduction in capacity of a Ni-Cd battery, which
occurs after the battery has been subjected to repeated shallow
discharges.
Memory was an issue only with the first generation of sealed Ni-Cd
cells, and relates to the way in which they are charged. Telecom Ni-Cd
batteries are comprised of vented or flooded cells which do not exhibit
memory effect.
"The so-called memory effect has been a problem with nickel-cadmium
batteries in some applications. Pocket, fiber and plastic-bonded plate
cells do not show this tendancy."

Here is a good description I found of voltage depression:

Ni-Cads have an undesirable characteristic that is caused by
constant overcharge and no, or infrequent, discharges, as
in standby applications. It is technically known as
"voltage depression" and commonly, but erroneously, called
"memory effect". This characteristic is only detectable when
a full discharge is performed. Thus, it is possible to believe
a full charge exists, while in fact it does not.

I'd trust what Saft says; where I used to work we used their batteries
exclusively for critical military applications. Sanyo does seem rather
confused about the phenomenon.

Leon
Thanks for the quote. I will send some more interpretations on the
subject if you are interested later.
As I said earlier the memory effect is a controversial subject , IMO
saying that one side is right wheras the other is wrong is sticking
ones neck out. Hey everyone has his own viewpoint and a right to judge
things based on his own experience, sensations etc.

Hans



.

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