Battery life

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:lphghs$qv6$1@dont-email.me...
"Jeff Liebermann" wrote in message
news:5cdor9p6oq2s1c0l11octjf95vvtq2nih9@4ax.com...

Ni-Cd cells like to be fully discharged every once in a while --
but not in a battery of series cells.

It's not just NiCd batteries, but all batteries.

Not as far as I know. Some lead-acid cells can be permanently damaged if
run down to zero even once. This happened to a Sony Discman battery that
was accidentally discharged slowly, over a period of about a week. It was
dead, dead, dead, and would not take a charge.
Click to expand...

With total discharge, sulphation can set in that quickly.

There's various methods for reviving sulphated cells, but you have to act
fast or the sulphate steals a big chunk of capacity.

And as already mentioned, most SLA become marginal at best if discharged
below about 11V.
 
"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:lphgqb$sr1$1@dont-email.me...
"Jeff Liebermann" wrote in message
news:5o6or9trqc0pbm30047h6j1sbvusvr4iq4@4ax.com...

In my never humble opinion:
1. There's no such thing as NiCd "memory effect", except in very
unique conditions found only in sintered plate batteries (found in
airplane starter batteries).
http://en.wikipedia.org/wiki/Memory_effect

I won't dispute the Wikipedia article.

However, I remember when the memory effect (or a memory effect) was
discovered in rechargeable toothbrushes, back in the '60s. Running the
cells all the way down reversed the effect.
Click to expand...

The story I first read that was NASA discovered memory effect - apparently
solar charged satellite batteries got charged on a very regular cycle when
the panels could see the sun, and the daily discharge pattern was always the
same - eventually the cells developed only having that much capacity.

Aggessive pulse charging is spectacularly good at curing memory effect in
Ni-Cd cells - my experiments with Ni-Mh were somewhat less impressive.
 
"Ian Field" wrote in message news:wsYuv.131494$iA.130513@fx31.am4...

Aggressive pulse charging is spectacularly good at curing memory effect in
Ni-Cd cells -- my experiments with Ni-Mh were somewhat less impressive.
Click to expand...

Motorola introduced a pulse charger for Honeywell Strobonar electronic-flash
packs back in the '60s. "Modern Photography" hailed it as a miracle -- it
could actually bring near-dead packs back to life, and significantly increase
the capacity of "wilted" packs.

Several years later, I asked Bert Keppler why the product had disappeared.
"Uh... the battery packs blew up too often."
 
On 07/03/2014 02:12 AM, captainvideo462009@gmail.com wrote:
I work on various alarm systems that use mostly two 12.0 volt 7.0 or 8.0 AH rechargeable lead acid gel cell batteries in series. Although fifteen or so years ago you could get up to ten years out of a typical set of Japanese gel cell batteries, these days it seems that three to five is about all you can expect from the Chinese knock offs that have flooded the market. I used to keep replacements in my van but I found that if they weren't used within a certain time frame they would sulfate. So now I don't keep any of these in stock, instead I buy them as I need them. It's a little more inconvenient but I always get fresh ones this way.

Today I replaced two batteries in a fire alarm panel for a customer. He had bought a case of batteries, he said "a few months ago" and asked me to use his. I used two batteries that he had in stock. The batteries had a 5/13 date code. Although the batteries came right up and worked fine I have to wonder, how well will these two batteries, that have been sitting in a box for over a year perform as compared to two fresh ones? I guess what I'm asking, if anyone knows, how much life span is gone or lost by these batteries just sitting in a box for fourteen months? Thanks, Lenny
Click to expand...

You could use them in Renee Everhart's alarm system. Nobody cares if she
gets burnt up in a fire.
 
On 07/09/2014 07:16 PM, Jeff Liebermann wrote:

Congrats on getting an article published, but I'm not going to pay $13
to download the issue:
Click to expand...

You sound so much like a Jew when you say, "I'm not going to pay so and
so for such and such."

Oh, wait you are a Jew.
 
On 07/09/2014 07:58 PM, Michael Black wrote:
On Wed, 9 Jul 2014, Jeff Liebermann wrote:


The summer issue traditionally was the best, lots of circuits rather
than multipage articles. So you'd get more for your money (plus, it was
a thicker issue, instead of two issues).

Michael

Tell the Jew that it's two thicker issues and you might have a sale.
Click to expand...
 
"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:lphogk$k9l$1@dont-email.me...
"Ian Field" wrote in message news:wsYuv.131494$iA.130513@fx31.am4...

Aggressive pulse charging is spectacularly good at curing memory effect
in
Ni-Cd cells -- my experiments with Ni-Mh were somewhat less impressive.

Motorola introduced a pulse charger for Honeywell Strobonar
electronic-flash packs back in the '60s. "Modern Photography" hailed it as
a miracle -- it could actually bring near-dead packs back to life, and
significantly increase the capacity of "wilted" packs.

Several years later, I asked Bert Keppler why the product had disappeared.
"Uh... the battery packs blew up too often."
Click to expand...

I have a pulse conditioner for Ni-Cd published in the current July/August
summer circuits issue of Elektor.

Its somewhat less aggressive than my original converted AT PSU, but the
cells remain cool throughout the treatment.
 
On Wed, 9 Jul 2014 18:48:23 +0100, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

I have a pulse conditioner for Ni-Cd published in the current July/August
summer circuits issue of Elektor.

Its somewhat less aggressive than my original converted AT PSU, but the
cells remain cool throughout the treatment.
Click to expand...

Congrats on getting an article published, but I'm not going to pay $13
to download the issue:
<http://www.elektor.com/elektor-magazine-en-july-august-2014>
What's an "Acupuntural NiCd Battery Conditioner"?
Anything to do with acupuncture? Push needles into the cell?
Feel no pain?


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
On Wed, 9 Jul 2014, Jeff Liebermann wrote:

On Wed, 9 Jul 2014 18:48:23 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:

I have a pulse conditioner for Ni-Cd published in the current July/August
summer circuits issue of Elektor.

Its somewhat less aggressive than my original converted AT PSU, but the
cells remain cool throughout the treatment.

Congrats on getting an article published, but I'm not going to pay $13
to download the issue:
http://www.elektor.com/elektor-magazine-en-july-august-2014
What's an "Acupuntural NiCd Battery Conditioner"?
Anything to do with acupuncture? Push needles into the cell?
Feel no pain?
Click to expand...
The summer issue traditionally was the best, lots of circuits rather than
multipage articles. So you'd get more for your money (plus, it was a
thicker issue, instead of two issues).

Michael
 
On Wed, 9 Jul 2014, Ian Field wrote:

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:lphogk$k9l$1@dont-email.me...
"Ian Field" wrote in message news:wsYuv.131494$iA.130513@fx31.am4...

Aggressive pulse charging is spectacularly good at curing memory effect in
Ni-Cd cells -- my experiments with Ni-Mh were somewhat less impressive.

Motorola introduced a pulse charger for Honeywell Strobonar
electronic-flash packs back in the '60s. "Modern Photography" hailed it as
a miracle -- it could actually bring near-dead packs back to life, and
significantly increase the capacity of "wilted" packs.

Several years later, I asked Bert Keppler why the product had disappeared.
"Uh... the battery packs blew up too often."

I have a pulse conditioner for Ni-Cd published in the current July/August
summer circuits issue of Elektor.

Its somewhat less aggressive than my original converted AT PSU, but the cells
remain cool throughout the treatment.
Click to expand...
I may have noticed that, I can't remember if the summer issue is on the
newsstand here yet. I know I looked at the current issue recently, and
soemthing made me wonder if I "knew" the writer. But I can't remember
what the project was, or if I saw a name I wondered about.

This isn't the first time a denizen of this hierarchy made it into
Elektor. Andre somebody who used to be a regular in sci.electronics.
basics had a simple project, I can't remember what.

Michael
 
"Michael Black" <et472@ncf.ca> wrote in message
news:alpine.LNX.2.02.1407091611420.16608@darkstar.example.org...
On Wed, 9 Jul 2014, Ian Field wrote:



"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:lphogk$k9l$1@dont-email.me...
"Ian Field" wrote in message news:wsYuv.131494$iA.130513@fx31.am4...

Aggressive pulse charging is spectacularly good at curing memory effect
in
Ni-Cd cells -- my experiments with Ni-Mh were somewhat less impressive.

Motorola introduced a pulse charger for Honeywell Strobonar
electronic-flash packs back in the '60s. "Modern Photography" hailed it
as a miracle -- it could actually bring near-dead packs back to life,
and significantly increase the capacity of "wilted" packs.

Several years later, I asked Bert Keppler why the product had
disappeared. "Uh... the battery packs blew up too often."

I have a pulse conditioner for Ni-Cd published in the current July/August
summer circuits issue of Elektor.

Its somewhat less aggressive than my original converted AT PSU, but the
cells remain cool throughout the treatment.
I may have noticed that, I can't remember if the summer issue is on the
newsstand here yet. I know I looked at the current issue recently, and
soemthing made me wonder if I "knew" the writer. But I can't remember
what the project was, or if I saw a name I wondered about.

This isn't the first time a denizen of this hierarchy made it into
Elektor. Andre somebody who used to be a regular in sci.electronics.
basics had a simple project, I can't remember what.
Click to expand...

Over the years I've had a couple of bicycle lights published.

Hopefully the July/August issue also includes; my take on what might be in
the house coded chip in a 2D LED flashlight and an E-cigarette battery
charger.
 
Thanks for the info about memory effect, much of that was new to me.

So, what is it that kills laptop batteries? I've had to replace several on the kids's laptops.

If there's no memory effect, and much of the damage is caused by overcharging, is that the problem with laptops? Should I be retrofitting a better wallwart to these?
 
On Sat, 12 Jul 2014 18:52:20 -0700 (PDT), Tim R <timothy42b@aol.com>
wrote:

>So, what is it that kills laptop batteries?

Laptop batteries are LiIon and do not have anything to do with the
mythical NiCd memory effect. Three things will help kill LiIon
batteries:
1. Leaving them on 100% charge forever.
2. Running them into the nearly total discharge.
3. Heat.

The details:
<http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries>
<http://www.mpoweruk.com/lithium_failures.htm>

>I've had to replace several on the kids's laptops.

Let me guess(tm). You left the charger plugged into the laptop 24x7?

If there's no memory effect, and much of the damage is caused by
overcharging, is that the problem with laptops?
Click to expand...

It's almost impossible to overcharge a LiIon battery. There's plenty
of electronics between the charger and the cells to prevent that. It's
also fairly easy to tell if a LiIon battery has been overcharged. They
just roll over and die with a shorted cell in a few hours.

However, leaving the battery on 99.99999% of capacity forever is just
as bad, but takes longer to trash the cells. See the aformentioned
URL's.

Should I be
retrofitting a better wallwart to these?
Click to expand...

No. You should be using the one that came with the laptops or an
equivalent replacement. Plugging in the wrong charger is more likely
to kill the laptop charging circuit than the battery.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:n0t3s9dc4330v86p37irghe2ggos1vut7v@4ax.com...
On Sat, 12 Jul 2014 18:52:20 -0700 (PDT), Tim R <timothy42b@aol.com
wrote:

So, what is it that kills laptop batteries?

Laptop batteries are LiIon and do not have anything to do with the
mythical NiCd memory effect. Three things will help kill LiIon
batteries:
1. Leaving them on 100% charge forever.
2. Running them into the nearly total discharge.
3. Heat.

The details:
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
http://www.mpoweruk.com/lithium_failures.htm

I've had to replace several on the kids's laptops.

Let me guess(tm). You left the charger plugged into the laptop 24x7?

If there's no memory effect, and much of the damage is caused by
overcharging, is that the problem with laptops?

It's almost impossible to overcharge a LiIon battery. There's plenty
of electronics between the charger and the cells to prevent that. It's
also fairly easy to tell if a LiIon battery has been overcharged. They
just roll over and die with a shorted cell in a few hours.

However, leaving the battery on 99.99999% of capacity forever is just
as bad, but takes longer to trash the cells. See the aformentioned
URL's.

Should I be
retrofitting a better wallwart to these?

No. You should be using the one that came with the laptops or an
equivalent replacement. Plugging in the wrong charger is more likely
to kill the laptop charging circuit than the battery.
Click to expand...

However remote - there's a possibility the wrong charger could over volt the
charge cut off chip in the laptop.

That would lead to full on over charging, thermal runaway and venting with
flaming gas.
 
What is "full" charge?
----------------------------

I mentioned a few weeks back that my HP notebook won't charge its battery if
its "charge state" is 95% or higher. This prevents the battery from receiving
a "full" charge until the charge state has dropped below 95%.

I normally leave the unit on charge, knowing that it can't be "overcharged". I
checked earlier today, and sure enough, the charge system reported 97% -- and
the battery wasn't being charged. That's as it should be.

At least one poster has stated that leaving a Li-ion battery at continual full
charge will damage it. But what is full charge?

http://www.batteryuniversity.com/learn/article/charging_lithium_ion_batteries

According to this Battery University article, "full" charge occurs at a
nominal 4.2V/cell. At this point, the charger is supposed to completely shut
off, with no trickle charge (not unlike a lead-acid battery).

It would appear, then, that with a /properly/ designed charger, overcharge is
impossible. It's safe to leave the charger plugged in indefinitely.

The following remarks seemed pertinent, though...

"If a lithium-ion battery must be left in the charger for operational
readiness, some chargers apply a brief topping charge to compensate for the
small self-discharge the battery and its protective circuit consume. The
charger may kick in when the open-circuit voltage drops to 4.05V/cell and turn
off again at a high 4.20V/cell. Chargers made for operational readiness, or
standby mode, often let the battery voltage drop to 4.00V/cell and recharge to
only 4.05V/cell instead of the full 4.20V/cell. This reduces voltage-related
stress and prolongs battery life.

"Some portable devices sit in a charge cradle in the on position. The current
drawn through the device is called the parasitic load and can distort the
charge cycle. Battery manufacturers advise against parasitic load while
charging because it induces mini-cycles, but this cannot always be avoided; a
laptop connected to the AC main is such a case. The battery is being charged
to 4.20V/cell and then discharged by the device. The stress level on the
battery is high because the cycles occur at the 4.20V/cell threshold.

"A portable device must be turned off during charge. This allows the battery
to reach the set threshold voltage unhindered, and enables terminating charge
on low current. A parasitic load confuses the charger by depressing the
battery voltage and preventing the current in the saturation stage to drop
low. A battery may be fully charged, but the prevailing conditions prompt a
continued charge. This causes undue battery stress and compromises safety."
 
On 7/8/2014 3:29 PM, William Sommerwerck wrote:
"Jeff Liebermann" wrote in message
news:5o6or9trqc0pbm30047h6j1sbvusvr4iq4@4ax.com...

In my never humble opinion:
1. There's no such thing as NiCd "memory effect", except in very
unique conditions found only in sintered plate batteries (found in
airplane starter batteries).
http://en.wikipedia.org/wiki/Memory_effect
Click to expand...

Some years ago when I worked in the television industry, portable
cameras of the day were powered with Ni-Cad battery packs. I recall
reading a white paper from Anton Bauer about this only somewhat true
memory effect. According to the paper a good battery cell that had an
apparent memory problem would still deliver the total amp hours expected
from the cell but at a reduced voltage of around .1V per cell.

The actual problem stated was manufacturers going the cheap route and
using too few cells for a given voltage...like using 10 cells to get a
nominal 12 volts. In this case that .1V per cell could add up to a full
volt. The solution used in high dollar cameras was to make the battery
packs using 12 cells and then using voltage regulation in the camera to
produce the needed 12V. Then even if a memory effect existed causing the
12 cell battery to lose a nominal 1.2V, there was still enough voltage
to regulate down to the required 12V.

I never made a huge personal study/experiment on this and it could have
just been marketing by the battery company because they always put 12
cells in their 12V batteries but it did make sense to me at the time.
 
"Jeff Liebermann" wrote in message
news:5o6or9trqc0pbm30047h6j1sbvusvr4iq4@4ax.com...

In my never humble opinion:
1. There's no such thing as NiCd "memory effect", except in very
unique conditions found only in sintered plate batteries (found in
airplane starter batteries).
http://en.wikipedia.org/wiki/Memory_effect
Click to expand...

I'm old enough to remember reading about this, circa 1959.

At that time, my father had an appliance store in Towson, MD. He got a number
of industry publications, including "Merchandising Week" (later "Electrical
Merchandising Week"). * These included articles discussing memory effect.

According to these articles, memory effect had reared its ugly head with
rechargeable electric toothbrushes. Users commonly put the handle back on the
charger after every use. So, unless a lot of people used the toothbrush every
day, it went through a shallow discharge/charge cycle. The result was that the
batteries lost their ability to hold a "full" charge.

The solution was discovered when people took their electric toothbrushes on
trips, and the toothbrush's power switch was accidentally turned "on" in the
suitcase, causing a "hard" battery rundown. When the battery was recharged, it
got most of its capacity back.

Now... //This is what the trade publications said.// Whether it is the truth
about "memory effect", I don't know.

* This magazine was my introduction to Charles Rodrigues' cartoons. (I didn't
read "Stereo Review" at the time.)
 
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