What is the trick to replacing rechargeable batteries please

[Phil Allison]

"William Sommerwanker"

Nicad chargers do not generally have temperature sensors, unless
they're built into the battery pack. Furthermore, a NiMH cell can
tolerate higher temperatures than a nicad so, again, a charger
designed for nicads is likely to shut off too soon rather than too
later.

** What an utterly STUPID non sequitur !!!

Why don't you think before yelling?

** JESUS H. CHRIST !!!!!!!!!!!!!!!!!!!!!!!!

YOU are one ARROGANT FUCKING IDIOT

There is NO sense in you para above at ALL !!

NiMH cells can be rather brutally charged without damaging them, at a rate
that most nicads would not tolerate.

** ABSOLUTE BOLLOCKS !!!!!!!!!!!

The reverse is the case.

Thus, the temperature sensor in a NiMH charger is likely to
be set higher than in a nicad charger. Placing NiMH cells in such a
charger
will likely lead to undercharging the cell,

** READ the very first line in this post.

YOUR WORDS !!!!!

Makes NONSENSE of your idiotic claims.

YOU DEMENTED FUCKWIT !!!!!!!!!!!!

I worked for several months at Microsoft Hardware. One of my projects
was documenting Microsoft's rapid charger for its cordless mice. Though
nicad and NiMH cells are more alike than different, the latter are
usually pushed to higher charging cut-off voltages and temperatures.
A nicad charger is not likely to damage NiMH cells.

** BOLLOCKS.

Chargers that are looking for the battery voltage to peak then come
DOWN will NEVER stop if NiMH cells are being used instead of NiCd.

Again, you have it backwards.

** YOU have it BACKWARDS

YOU FUCKING DEMENTED IDIOT !!!!!!!!!

Perhaps, you brainless ignoramus, you might
like to discuss this with the engineers I worked with.

** Let them and YOU SUCK on this FUCKHEAD:

http://www.powerstream.com/NiMH.htm

" The minus delta V bump that is indicative of end-of-charge is much less
pronounced in NiMH than NiCad, and it is very temperature dependent. To make
matters worse, new NiMH batteries can exhibit bumps in the curve early in
the cycle, particularly when cold. Also, NiMH are sensitive to damage on
overcharge when the charge rate is over C/10. Since the delta V bump is not
always easy to see, slight overcharge is probable. For this reason
PowerStream does not recommend using minus delta V as a termination
criterion for nickel metal hydride batteries. "

And:

http://www.mpoweruk.com/chargers.htm

" dT/dt Charge system NiMH batteries do not demonstrate such a pronounced
NDV voltage drop when they reach the end of the charging cycle as can be
seen in the graph above and so the NDV cut off method is not reliable for
ending the NiMH charge. Instead the charger senses the rate of increase of
the cell temperature per unit time. When a predetermined rate is reached the
rapid charge is stopped and the charge method is switched to trickle charge.
This method is more expensive but avoids overcharge and gives longer life.
Because extended trickle charging can damage a NiMH battery, the use of a
timer to regulate the total charging time is recommended. "


FOAD you PITA IMBECILE !!!



..... Phil

 

[Phil Allison]

"William Sommerwanker"


** FOAD you RIDICULOUS ARSEHOLE !!



..... Phil

 

[mike]

Amanda Ripanykhazov wrote:

I am hoping this question isnt too basic for this forum but I am
trying to replace some rechargeable batteries (in a Roomba: I
understand that generally only one or two start malfunctioning over
time and that it is usually the same one). It MUST be easier than I am
finding it.

I can just about solder on a connection but these rechargeable C cells
(nickel metal hydride? I am pretty sure they aren't lithium!) always
seem to have some sort of electro-welded rectangular plate connecting
the batteries which wont come off with a normal soldering gun? Or do
I just have to apply an inordinate amount of heat at exactly the
position where the ;nick' seems to be in the plate? Given the amount
of heat I seem to have applied to it already with no effect
whatsoever, to me it seems that this might damage the cell?

Is there some trick to doing this please or am i supposed to use a
dremel wheel to cut the plates off, leaving just the electro-weld to
which I solder the wire for the new cell?

The thing to take away from this thread is that EVERYBODY knows exactly
what to do, they just don't agree...violently!!
Be VERY CAREFUL acting on ANY information from this thread.

You MIGHT get more reliable info from
sci.chem.electrochem.battery

There's a reason that the label says, "don't open this battery pack."
This thread is why...

 

[William Sommerwerck]

The thing to take away from this thread is that EVERYBODY
knows exactly what to do, they just don't agree... violently!!
Be VERY CAREFUL acting on ANY information from this thread.

Whether or not the consensus view on this issue is correct, replacing
rechargeable batteries with non-OEM devices is NOT something someone with
little understanding of rechargeable batteries should do. I would simply buy
the iRobot batteries and forget about it.

The basic problem is that manufacturers often charge too much for
replacement batteries. If the battery pack is used in current models (no pun
intended), it shouldn't be expensive.

 

On Sat, 20 Feb 2010 20:01:53 -0800, "William Sommerwerck"
<grizzledgeezer@comcast.net>wrote:

many NiCd chargers use a temp sensor to determine
a full charge, and that will kill NiMH.

** Utter nonsense.

Temp detection is the MAIN way of detecting the end point
when charging NiMH cells.

The PROBLEM comes with NiCd chargers that use VOLTAGE
peak detection - cos NiMH cells never drop voltage like NiCds do.

Sorry, Phil, you've got it backwards.

NiMH cells can show a meaningful voltage drop at the end of charge. In
general, the harder the cell is charged, the greater the drop.

If you can place a thermistor on or near the NiMH cell, detecting the
temperature rise is usually the easiest and cheapest way to terminate
charge. This is particularly true if you're not hitting the cell hard and
don't have a big enough minus delta V to reliably detect.

Chargers that use voltage detection usually also use temperature detection,
as a belt-and-suspenders safety feature. One exception is the MAHA C9000
which uses only delta V (as far as I can tell), because it's hard to read
the cell's temperature through the plastic base of the charger.

Ut Oh! How dare you correct the almighty Phil Allison!

<grabs popcorn and a soda>

 

[William Sommerwerck]

Why do you think I should be afraid of you, you
pitiful excuse for a human being?

"You're nothing but a pack of cards." -- Alice

Dear P.O.S. Bill Phil is totally right about you. Furthermore
your always out there pushing your luck looking for some Internet
nut to one day make your day. Bill you trolling P.O.S. I hope you run
right into the arms of your Karmatic fate. I too am keeping and eye on
you waiting to see what happens to you.Yea I am the fellow, a victim
of one of your stupid sick jokes. While I am out here trying to make a
buck so I can slide food across the table to my hunger family you are
cracking on my wares. Well Bill F*CK you, you P.O.S. stupid troll.
You are definitely the pitiful excuse for a human being. Good luck on
your search, hope you secede Bill and get what you deserve.


The person who wrote is still objecting to a joke I made some time back
about his rebuilt CRTs, which related to the "going all the way to 11" joke
in "This is Spinal Tap".

His attitude suggests that anything he disagrees with or doesn't understand
is some sort of a personal attack.

 

[ancient-time-traveler]

On Feb 20, 11:19 pm, "William Sommerwerck"
<grizzledgee...@comcast.net> wrote:

Why do you think I should be afraid of you, you pitiful excuse for a human
being?

"You're nothing but a pack of cards." -- Alice

Dear P.O.S. Bill Phil is totally right about you. Furthermore
your always out there pushing your luck looking for some Internet nut
to one day make your day. Bill you trolling P.O.S. I hope you run
right into the arms of your Karmatic fate. I too am keeping and eye on
you waiting to see what happens to you.Yea I am the fellow, a victim
of one of your stupid sick jokes. While I am out here trying to make a
buck so I can slide food across the table to my hunger family you are
cracking on my wares. Well Bill F*CK you, you P.O.S. stupid troll.
You are definitely the pitiful excuse for a human being. Good luck on
your search, hope you secede Bill and get what you deserve.

 

[David Nebenzahl]

On 2/21/2010 1:41 PM ancient-time-traveler spake thus:

On Feb 21, 12:56 pm, "William Sommerwerck"
grizzledgee...@comcast.net> wrote:

Why do you think I should be afraid of you, you
pitiful excuse for a human being?
"You're nothing but a pack of cards." -- Alice

Dear P.O.S. Bill Phil is totally right about you. Furthermore
your always out there pushing your luck looking for some Internet
nut to one day make your day. Bill you trolling P.O.S. I hope you run

[...]

The person who wrote is still objecting to a joke I made some time back
about his rebuilt CRTs, which related to the "going all the way to 11" joke
in "This is Spinal Tap".

His attitude suggests that anything he disagrees with or doesn't understand
is some sort of a personal attack.

Dear P.O.S. Bill As usual you Trolling P.O.S. you got it all wrong
and misrepresented everything. The CRT as you fully remember was OEM

[blah blah blah snipped]

Hey, Mr. Trollface: Nobody gives a *SHIT* about the ancient history of
your old arguments. Nobody. Please just give it up.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

 

[ancient-time-traveler]

On Feb 21, 12:56 pm, "William Sommerwerck"
<grizzledgee...@comcast.net> wrote:

Why do you think I should be afraid of you, you
pitiful excuse for a human being?
"You're nothing but a pack of cards." -- Alice

Dear P.O.S. Bill        Phil is totally right about you. Furthermore
your always out there pushing your luck looking for some Internet
nut to one day make your day. Bill you trolling P.O.S. I hope you run
right into the arms of your Karmatic fate. I too am keeping and eye on
you waiting to see what happens to you.Yea I am the fellow, a victim
of one of your stupid sick jokes. While I am out here trying to make a
buck so I can slide food across the table to my hunger family you are
cracking on my wares. Well Bill F*CK you, you P.O.S. stupid troll.
You are definitely the pitiful excuse for a human being. Good luck on
your search, hope you secede Bill and get what you deserve.

The person who wrote is still objecting to a joke I made some time back
about his rebuilt CRTs, which related to the "going all the way to 11" joke
in "This is Spinal Tap".

His attitude suggests that anything he disagrees with or doesn't understand
is some sort of a personal attack.

Dear P.O.S. Bill As usual you Trolling P.O.S. you got it all wrong
and misrepresented everything. The CRT as you fully remember was OEM
not a cheap Rebuilt Furthermore you do not even know me to make such
a Quantum leap judgment about me. Just another example in a long list
of examples how you readily talk about things as the consummate expert
when in reality you are completely clueless, a idiot's imbecile. As
far as Jokes I could call you the butt of the Joke but you probably
like that so I will not.
..

 

[Jim Yanik]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in
news:hlrin9$iic$1@news.eternal-september.org:

The thing to take away from this thread is that EVERYBODY
knows exactly what to do, they just don't agree... violently!!
Be VERY CAREFUL acting on ANY information from this thread.

Whether or not the consensus view on this issue is correct, replacing
rechargeable batteries with non-OEM devices is NOT something someone
with little understanding of rechargeable batteries should do. I would
simply buy the iRobot batteries and forget about it.

The basic problem is that manufacturers often charge too much for
replacement batteries. If the battery pack is used in current models
(no pun intended), it shouldn't be expensive.

Manufacturers don't want to sell replacement parts.
Also,replacement parts are handled differently than manufacturing
stock,they get inventoried and taxed,and those costs get added to the part
price.
a realistic alternative is to go to a rebuilder and have them make you a
new pack from new cells.(of the same type/chemistry as OEM.)

--
Jim Yanik
jyanik
at
localnet
dot com

 

[Dave Plowman (News)]

In article <hlrhg0$vc4$2@news.eternal-september.org>,
mike <spamme0@go.com> wrote:

The thing to take away from this thread is that EVERYBODY knows exactly
what to do, they just don't agree...violently!!
Be VERY CAREFUL acting on ANY information from this thread.

You MIGHT get more reliable info from
sci.chem.electrochem.battery

There's a reason that the label says, "don't open this battery pack."
This thread is why...

I'd also stay indoors if I were you...

--
*You never really learn to swear until you learn to drive *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Dave Plowman (News)]

In article <hlrin9$iic$1@news.eternal-september.org>,
William Sommerwerck <grizzledgeezer@comcast.net> wrote:

The thing to take away from this thread is that EVERYBODY
knows exactly what to do, they just don't agree... violently!!
Be VERY CAREFUL acting on ANY information from this thread.

Whether or not the consensus view on this issue is correct, replacing
rechargeable batteries with non-OEM devices is NOT something someone
with little understanding of rechargeable batteries should do. I would
simply buy the iRobot batteries and forget about it.

Assuming someone has reasonable DIY skills and sticks to tagged
replacement cells of the same type as the originals there's little to
worry about. It's certainly not any more hazardous than many common tasks
people take on.

--
*Marriage changes passion - suddenly you're in bed with a relative*

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Jeff Liebermann]

On Sat, 20 Feb 2010 07:29:40 -0600, Jim Yanik <jyanik@abuse.gov>
wrote:

many NiCd chargers use a temp sensor to determine a full charge,and that
will kill NiMH.

Sorta. Most NiCd chargers use the voltage drop at the end of charge.
NiMH batteries do have a similar voltage drop at EOC, but it's far
less obvious or easy to detect. NiMH chargers tend to use temperature
and either the a zero slope (no rise in voltage), or a negative
voltage drop. Since the temperature peak ocurrs AFTER the negative
slope, there's a really good chance that using a temp sensor will
cause overcharging.

This might explain it better:
<http://www.powerstream.com/NiMH.htm>
<http://pdfserv.maxim-ic.com/en/ds/1666.pdf>


--
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

 

[William Sommerwerck]

Assuming someone has reasonable DIY skills and sticks
to tagged replacement cells of the same type as the originals
there's little to worry about. It's certainly not any more hazardous
than many common tasks people take on.

I would still be cautious. For one thing, you want to be sure the
replacement cells have at least the same capacity as the originals. Higher
is probably okay, lower is almost certainly not.

If a battery dealer can make up a pack for you, it might be a good idea to
take the old pack in and have them do it. However...

My experience with non-OEM Li-ion cells has been that, even when they come
from a recognized manufacturer, they quickly deteriorate. They're a complete
waste of money. Nicads and NiMH cells aren't so critical, but there is the
possibility that the charger for the product might have been designed for a
particular battery from a particular company, and might not work correctly
with other batteries.

Just to dump on Mr. Allison again... I've replaced the nicads in several
Polaroid #365 electronic flashes with MAHA 2200mAH tabbed NiMH cells. The
original cells were designed for rapid charge, and the charger is supposed
to fully recharge them in one hour. The charger works fine with the NiMH
cells, and shuts off properly (even though it's probably not at would be
full charge for those cells).

 

[William Sommerwerck]

The basic problem is that manufacturers often charge too much for
replacement batteries. If the battery pack is used in current models
(no pun intended), it shouldn't be expensive.

Manufacturers don't want to sell replacement parts.

True, but they are legally obliged to. Unfortunately, there doesn't seem to
be much enforcement of the laws.

Also, replacement parts are handled differently than manufacturing
stock, they get inventoried and taxed, and those costs get added to
the part price.

True, but... That doesn't change the fact some companies -- such as
Thomson -- GOUGE. Please tell me how two AAA NiMH cells with a little cable
and socket can sell for almost $25. And this is a current-production
battery.

 

[William Sommerwerck]

Many NiCd chargers use a temp sensor to determine
a full charge, and thatwill kill NiMH.

Sorta. Most NiCd chargers use the voltage drop at the end of charge.

You mean most /rapid-charge/ nicad chargers use the voltage drop. If you're
charging at 0.1C, you don't usually need to terminate the charge. And if you
use just a resistor to set that charge rate at 1.0V, the current will drop
to below 0.1C at the end of charge.

I've charged NiMH cells in conventional non-rapid-charge nicad chargers. It
works fine.

NiMH batteries do have a similar voltage drop at EOC, but it's far
less obvious or easy to detect.

The harder the cell is charged, the greater the drop. Microsoft used a hard
charge which produced an easily measured drop.

This might explain it better:
http://www.powerstream.com/NiMH.htm

I'm not sure all the information at this site is correct. The statement that
voltage drop should not be used is questionable. The Microsoft charger used
both delta V and either T or delta T (I don't remember) to terminate charge.

 

[Jim Yanik]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in
news:hlsmi1$ik0$1@news.eternal-september.org:

The basic problem is that manufacturers often charge too much for
replacement batteries. If the battery pack is used in current models
(no pun intended), it shouldn't be expensive.

Manufacturers don't want to sell replacement parts.

True, but they are legally obliged to. Unfortunately, there doesn't
seem to be much enforcement of the laws.


Also, replacement parts are handled differently than manufacturing
stock, they get inventoried and taxed, and those costs get added to
the part price.

True, but... That doesn't change the fact some companies -- such as
Thomson -- GOUGE. Please tell me how two AAA NiMH cells with a little
cable and socket can sell for almost $25. And this is a
current-production battery.

A company(Fortune 500 at the time) I used to work for would raise
their parts prices as the product that the parts went into got closer to
the end of support period.
I was told this was to "encourage" customers to buy a newer instrument,by
raising the cost of repairs.

It didn't matter that the parts were "in current production".

--
Jim Yanik
jyanik
at
localnet
dot com

 

[Jim Yanik]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in
news:hlsn2u$n0p$1@news.eternal-september.org:

Many NiCd chargers use a temp sensor to determine
a full charge, and thatwill kill NiMH.

Sorta. Most NiCd chargers use the voltage drop at the end of charge.

You mean most /rapid-charge/ nicad chargers use the voltage drop. If
you're charging at 0.1C, you don't usually need to terminate the
charge. And if you use just a resistor to set that charge rate at
1.0V, the current will drop to below 0.1C at the end of charge.

I've charged NiMH cells in conventional non-rapid-charge nicad
chargers. It works fine.


NiMH batteries do have a similar voltage drop at EOC, but it's far
less obvious or easy to detect.

The harder the cell is charged, the greater the drop. Microsoft used a
hard charge which produced an easily measured drop.


This might explain it better:
http://www.powerstream.com/NiMH.htm

I'm not sure all the information at this site is correct. The
statement that voltage drop should not be used is questionable. The
Microsoft charger used both delta V and either T or delta T (I don't
remember) to terminate charge.

Yes,those slow chargers don't have any sort of charge sensing.
they're just transformers,rectifier and current limit resistor,if the XFMR
doesn't limit on it's own.
So,you have no idea of charge time,it's just a guess.

IMO,rechargeables last much longer with a fast charger.

--
Jim Yanik
jyanik
at
localnet
dot com

 

[William Sommerwerck]

A company (Fortune 500 at the time) I used to work for would raise
their parts prices as the product that the parts went into got closer
to the end of support period.
I was told this was to "encourage" customers to buy a newer instrument
by raising the cost of repairs.

It didn't matter that the parts were "in current production".

Hardly surprising. I could tell you some stories about my dealings with
Sony, but I won't. Suffice it to say that I made friends with the parts
honcha, who was occasionally able to help me a bit. Though her job was
eliminated, we still talk occasionally.

In "encouraging" customers to buy new products -- rather than repairing the
old -- businesses contribute to waste and pollution.

 

[William Sommerwerck]

IMO, rechargeables last much longer with a fast charger.

That might be true. One of the non-professional Web reviews of NiMH chargers
revealed that there was significant difference among them in how much they
heated the cell.