Difference in NiCad replacement batteries

[mike]

William Sommerwerck wrote:

Probably not. The Norelco "charger" is probably little more than a
resistor
in series with the power supply. A NiMH should have no trouble with that.

As I understand it, the problem with this approach is the question of
shutting off the charge when the battery is full. NiMH cells are less
tolerant of being overcharged than NiCd, and are best used with a
charger that has a somewhat more sensitive full-charge detector (e.g.
zero-delta-V and/or direct temperature sense, rather than negative-
delta-V as was often used with NiCd cells.

This isn't a problem if you're charging at a fairly low rate. A good-quality
cell -- nicad or NiMH -- will tolerate an indefinite low ("trickle") charge.

I'd like to see a reference that supports that.

NiCd batteries are very tolerant of trickle charging.
Early NiMH cells were very INTOLERANT of trickle charging.
Lots has changed over the years. Maybe they're better now,
but I'd like to see some vendor info on that.

If the resistor is chosen to give a 0.1C charge rate when the cell is at
about 1V, the charge rate when the cell has "fully" charged will be rather
lower ("depending").

It's only in the past decade or so that rapid-charging with auto-cutoff has
become commonplace. Prior to that, almost every nicad device was charged
with a simple series resistor. And guess what? It worked.

Here's some empirical evidence.
Power tools have historically had three charge modes.
The cheapest have a trickle charger. People leave 'em on charge all the
time.
The "better" tools have a fast charger with a thermal coutout. The cell
gets HOT and the charge is terminated by the thermal cutout.

The "best" tools have a fast charger that often measures -deltaV for NiCds
or 0delatV for NiMH.

So, here's the experiment.

Go to a garage sale. Almost every garage sale has at least one battery
powered drill.
Have you EVER found a battery powered drill at a garage sale that had a
good battery? I haven't.

As I said earlier, I have a Polaroid #365 electronic flash with NiMH cells
that replaced the original nicads. The #363 rapid charger has no trouble
stopping and switching to trickle charge. It was designed almost 45 years
ago..

The bottom line is that you should always use the EXACT battery chemistry,
type, model number with the charger designed exactly for that battery.

If you're willing to reverse-engineer the charging circuit, you can often
use alternative cells.
Or you can redesign the charger to match the cells.
Or you can just get lucky with any random selection.
I've been lucky 99+% of the time. But I have also been unlucky.
One day I'll find the rest of the battery pack that exploded
when the lawnmower throws it thru a window.
YMMV

 

[William Sommerwerck]

"mike" <spamme9@gmail.com> wrote in message
news:j2840v$u8v$1@dont-email.me...

Here's some empirical evidence.
Power tools have historically had three charge modes.
The cheapest have a trickle charger. People leave 'em on charge all the
time.
The "better" tools have a fast charger with a thermal coutout. The cell
gets HOT and the charge is terminated by the thermal cutout.

The "best" tools have a fast charger that often measures -deltaV for NiCds
or 0delatV for NiMH.

So, here's the experiment.

Go to a garage sale. Almost every garage sale has at least one battery
powered drill.
Have you EVER found a battery powered drill at a garage sale that had a
good battery? I haven't.

If it had a good battery, it wouldn't be at the garage sale.

ba-DUM!

As I said earlier, I have a Polaroid #365 electronic flash with NiMH
cells
that replaced the original nicads. The #363 rapid charger has no trouble
stopping and switching to trickle charge. It was designed almost 45 years
ago..

The bottom line is that you should always use the EXACT battery chemistry,
type, model number with the charger designed exactly for that battery.

That's no longer possible.

NiMH "behavior" is "close-enough" to nicad that replacement often works
well.

 

[mike]

William Sommerwerck wrote:

"mike" <spamme9@gmail.com> wrote in message
news:j2840v$u8v$1@dont-email.me...

Here's some empirical evidence.
Power tools have historically had three charge modes.
The cheapest have a trickle charger. People leave 'em on charge all the
time.
The "better" tools have a fast charger with a thermal coutout. The cell
gets HOT and the charge is terminated by the thermal cutout.

The "best" tools have a fast charger that often measures -deltaV for NiCds
or 0delatV for NiMH.

So, here's the experiment.

Go to a garage sale. Almost every garage sale has at least one battery
powered drill.
Have you EVER found a battery powered drill at a garage sale that had a
good battery? I haven't.

If it had a good battery, it wouldn't be at the garage sale.

ba-DUM!

You're letting your desire to be right overshadow your analysis.
How many battery powered drills does the average family need?
When every other garage sale has one, two or even three dead
drills, the statistics are hard to ignore.
The drills are rarely dead. It's almost always the batteries.

Take a design that was intended to be the cheapest initial
purchase cost based on the crappiest batteries available at the time.
Replace the cells with ones having 5x the capacity.
Now, even if the charger design was proper, fast charge termination
is unlikely to be anywhere near correct...as in "never terminates".

Sure, it often works. You feeling lucky?

As I said earlier, I have a Polaroid #365 electronic flash with NiMH
cells
that replaced the original nicads. The #363 rapid charger has no trouble
stopping and switching to trickle charge. It was designed almost 45 years
ago..

The bottom line is that you should always use the EXACT battery chemistry,
type, model number with the charger designed exactly for that battery.

That's no longer possible.

NiMH "behavior" is "close-enough" to nicad that replacement

often

I'm in complete agreement. The only thing we seem to differ on is the
consequences of when it DOESN'T work and if those consequences
are acceptable.


works

well.

 

[Phil Allison]

"William Sommerwerck"

Got some 50 year old German nicad packs that still work.

Ah, German precision...

** Nah - probably Jewish and too terrified to stop.





..... Phil

 

[William Sommerwerck]

"mike" <spamme9@gmail.com> wrote in message
news:j285g4$5r4$1@dont-email.me...

You're letting your desire to be right overshadow your analysis.
How many battery powered drills does the average family need?
When every other garage sale has one, two or even three dead
drills, the statistics are hard to ignore.
The drills are rarely dead. It's almost always the batteries.

Take a design that was intended to be the cheapest initial
purchase cost based on the crappiest batteries available at the time.
Replace the cells with ones having 5x the capacity.
Now, even if the charger design was proper, fast charge termination
is unlikely to be anywhere near correct...as in "never terminates".

Sure, it often works. You feeling lucky?

"Well, do ya, punk?"

Not that many years ago I bought a Ryobi drill at Home Despot. It had a
conventional, non-rapid-charging charger. The battery died (in my view)
prematurely, and (violating Federal law) Ryobi could not supply a
replacement pack. So I bought a new drill (a Ryobi with a modular pack). Had
a replacement been available, I'd probably still be using the original.

Your correct observation about the average family rarely needing more than
one cordless drill only confirms my point.

You missed the point I was making -- rapid chargers almost always have some
form of auto cutoff. The kind of charging I was talking about (which I made
perfectly clear) was the "resistor-in-series-with-the-power-supply" type.
This is not a rapid-charge -- though it does charge faster than when the
cell voltage is lower. Such a system works fairly well -- eg, a Dust Buster.
I've gotten a good 200 recharges on my Model 5000, because I let the cells
run down before recharging, and I don't leave the unit on the charger all
the time.

NiMH "behavior" is "close-enough" to nicad that replacement
[often] works well.

I'm in complete agreement. The only thing we seem to differ on is the
consequences of when it DOESN'T work and if those consequences
are acceptable.

I completely agree with your complete agreement. The confusion occurred
because you misread me. I do not advocate rapid charging of any kind of cell
without a "fool-proof" shutoff system. I'm surprised at how far my MAHA
C9000 pushes NiMH cells. I keep an eye on it, and sometimes terminate the
charge cycle manually, because the cell has gotten warmer than I like, even
though the cell voltage is above 1.4 volts. I'm so cautious, I rarely charge
faster than 0.3C, though MAHA and other NiMH manufacturers recommend as high
as 0.5C.

 

[Steve Stone]

I have had good luck with LSD NiMH, like the Sanyo Eneloop for use in
cameras and two way radio gear.

 

[William Sommerwerck]

"Steve Stone" <spfleck@citlink.net> wrote in message
news:AoQ1q.578798$SG4.192441@newsfe03.iad...

I have had good luck with LSD NiMH, like the Sanyo Eneloop
for use in cameras and two-way-radio gear.

Do you use them when you go on trips?

 

[Jeff Liebermann]

On Sun, 14 Aug 2011 02:18:37 -0700, mike <spamme9@gmail.com> wrote:

This isn't a problem if you're charging at a fairly low rate. A good-quality
cell -- nicad or NiMH -- will tolerate an indefinite low ("trickle") charge.

I'd like to see a reference that supports that.

<http://batteryuniversity.com/learn/article/charging_nickel_metal_hydride>
"It is difficult, if not impossible, to slow-charge a NiMH
battery. At a C-rate of 0.1 to 0.3C, the voltage and temperature
profiles fail to exhibit defined characteristics to measure the
full-charge state accurately and the charger must depend on a
timer. Harmful overcharge will occur if a fixed timer controls the
charge. This is especially apparent when charging partially or
fully charged batteries."
Not exactly what you wanted, but a good reason why a "trickle" or
"maintaining" charge doesn't really work.

NiCd batteries are very tolerant of trickle charging.

Nope. I've successfully killed NiCd batteries in (Jedi series) radio
chargers that produce a 0.1c "maintaining" charge when fully charged.
After about a year of continuous charging at 0.1c, the batteries were
all dead. That's what happened to the local hospital emergency
network. The county issued MT2000 radios and chargers to all the
hospitals in the county. In case of emergency, they could all
communicate with each other through a repeater or directly. Once a
week, there was a test to make sure things were working. No problems
for 3 years until I decided to check the batteries. I found a mix of
NiCd and NiMH batteries. All that I tested were dead. The radios
would work for about 2 minutes, which was just long enough for the
test but not long enough for useful operation. Since the batteries
were never discharged, I concluded that the 0.1c maintaining charge
was the culprit.

--
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]

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:n8pf47l7qnoqmh8ak0mrectdb5fs50ndld@4ax.com...

On Sun, 14 Aug 2011 02:18:37 -0700, mike <spamme9@gmail.com> wrote:

This isn't a problem if you're charging at a fairly low rate. A
good-quality
cell -- nicad or NiMH -- will tolerate an indefinite low ("trickle")
charge.

I'd like to see a reference that supports that.

http://batteryuniversity.com/learn/article/charging_nickel_metal_hydride
"It is difficult, if not impossible, to slow-charge a NiMH
battery. At a C-rate of 0.1 to 0.3C, the voltage and temperature
profiles fail to exhibit defined characteristics to measure the
full-charge state accurately and the charger must depend on a
timer. Harmful overcharge will occur if a fixed timer controls the
charge. This is especially apparent when charging partially or
fully charged batteries."
Not exactly what you wanted, but a good reason why a "trickle" or
"maintaining" charge doesn't really work.

If that's true (and I assume it is), it's the first really significant
difference between nicads and NiMHs I've heard of.

It also explains why my C9000 charger doesn't shut off when I charge at
"only" 0.3. Guess I'll have to change the way I charge."

\

NiCd batteries are very tolerant of trickle charging.

Nope. I've successfully killed NiCd batteries in (Jedi series) radio
chargers that produce a 0.1c "maintaining" charge when fully charged.
After about a year of continuous charging at 0.1c, the batteries were
all dead. That's what happened to the local hospital emergency
network. The county issued MT2000 radios and chargers to all the
hospitals in the county. In case of emergency, they could all
communicate with each other through a repeater or directly. Once a
week, there was a test to make sure things were working. No problems
for 3 years until I decided to check the batteries. I found a mix of
NiCd and NiMH batteries. All that I tested were dead. The radios
would work for about 2 minutes, which was just long enough for the
test but not long enough for useful operation. Since the batteries
were never discharged, I concluded that the 0.1C maintaining charge
was the culprit.

I stand corrected. HOWEVER... No one would consider 0.1C a trickle charge,
as it has traditionally been the "standard" charge for regular nicad cells.

It's also possible this might have been a memory effect.

 

[Phil Allison]

"William Sommerwanker"

"Steve Stone"

I have had good luck with LSD NiMH, like the Sanyo Eneloop
for use in cameras and two-way-radio gear.

Do you use them when you go on trips?

** Let him who is without sin cast the first Stone ...

Tim is turning in his grave...




..... Phil

 

[Jim Yanik]

Jeff Liebermann <jeffl@cruzio.com> wrote in
news:n8pf47l7qnoqmh8ak0mrectdb5fs50ndld@4ax.com:

On Sun, 14 Aug 2011 02:18:37 -0700, mike <spamme9@gmail.com> wrote:

This isn't a problem if you're charging at a fairly low rate. A
good-quality cell -- nicad or NiMH -- will tolerate an indefinite
low ("trickle") charge.

I'd like to see a reference that supports that.

http://batteryuniversity.com/learn/article/charging_nickel_metal_hydrid
e
"It is difficult, if not impossible, to slow-charge a NiMH
battery. At a C-rate of 0.1 to 0.3C, the voltage and temperature
profiles fail to exhibit defined characteristics to measure the
full-charge state accurately and the charger must depend on a
timer. Harmful overcharge will occur if a fixed timer controls the
charge. This is especially apparent when charging partially or
fully charged batteries."
Not exactly what you wanted, but a good reason why a "trickle" or
"maintaining" charge doesn't really work.

NiCd batteries are very tolerant of trickle charging.

Nope. I've successfully killed NiCd batteries in (Jedi series) radio
chargers that produce a 0.1c "maintaining" charge when fully charged.
After about a year of continuous charging at 0.1c, the batteries were
all dead. That's what happened to the local hospital emergency
network. The county issued MT2000 radios and chargers to all the
hospitals in the county. In case of emergency, they could all
communicate with each other through a repeater or directly. Once a
week, there was a test to make sure things were working. No problems
for 3 years until I decided to check the batteries. I found a mix of
NiCd and NiMH batteries. All that I tested were dead. The radios
would work for about 2 minutes, which was just long enough for the
test but not long enough for useful operation. Since the batteries
were never discharged, I concluded that the 0.1c maintaining charge
was the culprit.

OTOH,the B&D Dustbuster I had was designed to stay on the charger when not
in use,and it lasted 10 years before I had to have another NiCd pack
installed. that new pack lasted almost as long.
I've seen NiCds listed at DigiKey specifically intended for staying on the
trickle charger when not in use.

--
Jim Yanik
jyanik
at
localnet
dot com

 

[Jeff Liebermann]

On Sun, 14 Aug 2011 08:34:04 -0700, "William Sommerwerck"
<grizzledgeezer@comcast.net> wrote:

If that's true (and I assume it is), it's the first really significant
difference between nicads and NiMHs I've heard of.

I must admit that I didn't know that either. I had always assumed the
NiCd and NiMH cells were interchangeable in chargers. I guess not.

It also explains why my C9000 charger doesn't shut off when I charge at
"only" 0.3. Guess I'll have to change the way I charge."

I've been playing with charging individual cells at 5C or higher.
Works fine as long as you know exactly how long to charge, condition
of the cell, and ambient temp. From experience, the battery does NOT
get hot until it's overcharged.

I stand corrected. HOWEVER... No one would consider 0.1C a trickle charge,
as it has traditionally been the "standard" charge for regular nicad cells.

I didn't say trickle charge. According to Motorola, it's a
"maintaining" charge, whatever that means. I agree that a trickle
charge would be much less. However, my experience is that you cannot
charge a NiCd battery with anything less than about 0.05C. It just
never comes to full charge. I don't know what causes this effect and
don't want to go Googling for references right now.

It's also possible this might have been a memory effect.

There's no such thing as NiCd memory effect unless you're talking
about space qualified batteries.
<http://en.wikipedia.org/wiki/Memory_effect>
I have yet to see data, numbers, and reproduceable tests that
demonstrate memory effect. What I have seen are problems with
electrolyte loss, caused by overcharging and subsequent venting, that
mimick the problem. Incidentally, I found this by carefully weighing
the better before and after overcharging. It's not much loss, but
it's always present.


--
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]

On Sun, 14 Aug 2011 10:58:33 -0500, Jim Yanik <jyanik@abuse.gov>
wrote:

OTOH,the B&D Dustbuster I had was designed to stay on the charger when not
in use,and it lasted 10 years before I had to have another NiCd pack
installed. that new pack lasted almost as long.

My Dustbuster battery died after about 2 years of sitting on permanent
charge. I didn't investigate. I installed a home made battery pack
about a year ago. Works fine. I think the original batteries may
have had a problem.

I've seen NiCds listed at DigiKey specifically intended for staying on the
trickle charger when not in use.

Never heard of such a thing, but I'll look.

What creates the problem is that many vendor rate their drills,
laptops, and devices by how long it will run on battery power. In
order to improve their numbers, they try to cram as much charge into
the battery as possible. That works well enough with a new battery,
but as the battery gets older, the table driven and timer charge
controllers start to overcharge. That causes heating, which is an
invitation to a premature demise of the battery.

In my never humble opinion, there's only one correct way to charge
batteries, and that's with a "coulomb counting" charge controller. It
measures the current in, runs tests on battery capacity, and adjust
the charge current and timing as necessary. They can programmed for
almost any desired attribute (long battery life, fast charging,
conservative capacity, etc), and will compensate for battery aging.
Many of the charge controller chips made for LiIon will work for NiMH.


--
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]

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
newsu4g47hb9cpdv5tfb55thfscb6cjn7m6mn@4ax.com...

I have yet to see data, numbers, and reproduceable tests that
demonstrate memory effect. What I have seen are problems with
electrolyte loss, caused by overcharging and subsequent venting, that
mimick the problem. Incidentally, I found this by carefully weighing
the better before and after overcharging. It's not much loss, but
it's always present.

Reports on "memory effect" go back almost 50 years to the introduction of
cordless toothbrushes, which were commonly used briefly before being
recharged. They would (supposedly) lose capacity.

Then people whose toothbrushes were accidentally activated in their luggage
and thoroughly run down recovered most of their capacity (the toothbrushes,
not the people). GE supposedly discovered the cause of memory effect
(electrode crystallization), but no cells that addressed the problem were
ever manufactured, that I know of.

 

[William Sommerwerck]

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:qj5g479u8gmhuq4keshf22l2b887liba33@4ax.com...

In my never humble opinion, there's only one correct way to charge
batteries, and that's with a "coulomb counting" charge controller. It
measures the current in, runs tests on battery capacity, and adjust
the charge current and timing as necessary. They can programmed for
almost any desired attribute (long battery life, fast charging,
conservative capacity, etc), and will compensate for battery aging.
Many of the charge controller chips made for LiIon will work for NiMH.

You might like the MAHA C9000.

 

[Bob F]

Puddin' Man wrote:

On Sat, 6 Aug 2011 08:00:20 -0700, "William Sommerwerck"
grizzledgeezer@comcast.net> wrote:

You could easily get more than twice that capacity by using NiMH
cells or a pack thereof, but if the charge-control circuit in the
shaver is designed for NiCd it might not work all that well with
NiMH (might over- or under-charge the battery, shorten its life,
etc.).

Probably not. The Norelco "charger" is probably little more than a
resistor in series with the power supply. A NiMH should have no
trouble with that.

Why not get some NiMH cells with tabs from Thomas Distributing? The
ones I used in my Polaroid #365 electronic flash work fine, and the
#363 rapid charger -- designed for nicads -- shuts off properly.

Hmmmmmmm. I peruse
http://www.streetdirectory.com/travel_guide/159640/technology/nimh_vs_nicad_vs_li_ion.html
and it sez longer (than NiMh) life cycles for NiCd.

If true, I'd likely be better off with NiCd. No?

It says NiMH has larger capacity, but NiCd has longer run time. You say what?

 

[Phil Allison]

"Bob Fool"

Hmmmmmmm. I peruse
http://www.streetdirectory.com/travel_guide/159640/technology/nimh_vs_nicad_vs_li_ion.html
and it sez longer (than NiMh) life cycles for NiCd.

If true, I'd likely be better off with NiCd. No?

It says NiMH has larger capacity, but NiCd has longer run time.

** That is a very obvious error.



.... Phil

 

[Jeff Liebermann]

On Mon, 15 Aug 2011 07:17:32 -0700, "Bob F" <bobnospam@gmail.com>
wrote:

Hmmmmmmm. I peruse
http://www.streetdirectory.com/travel_guide/159640/technology/nimh_vs_nicad_vs_li_ion.html
and it sez longer (than NiMh) life cycles for NiCd.

I'm always suspicious of information sites that don't bother to supply
any numbers. This looks like a more useful comparison:
<http://www.ka7oei.com/nicds.html>
If you want authoritative reading, start here:
<http://batteryuniversity.com>

If true, I'd likely be better off with NiCd. No?

You decide. It's not so much the chemistry, as it is how it's used.
See below.

It says NiMH has larger capacity, but NiCd has longer run time. You say what?

NiCd can handle more charge cycles. For NiCd, is you do everything
right you'll get perhaps 1000 charge cycles before the battery
deteriorates to about half capacity. For NiMH, you'll get perhaps 600
charge cycles.

Doing the math for typical batteries, NiCd will deliver:
0.7A-hr * 1000 cycles = 700A-hr
while NiMH will deliver:
2.0A-hr * 600 cycles = 1200A-hr
So, if you recycle your batteries when they're half dead, you'll get
almost twice the lifetime with a NiMH than with NiCd, where you need
to charge NiMH about 40% less often.

However, that's at best, under ideal conditions, with a device that
favors NiMH (i.e. no self-discharge problems and moderately high peak
current). If you do something non-ideal, such as charge the batteries
every day at the same time, you'll get 1000 days out of the NiCd and
600 days out of the NiMH which makes the NiCd the winner. NiMH is the
superior technology only if you charge the batteries when they're
almost fully discharged (at the knee in the discharge curve). If you
recharge by the clock, then NiCd is better because you can recharge it
more often.




--
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]

On Sun, 14 Aug 2011 11:54:12 -0700, "William Sommerwerck"
<grizzledgeezer@comcast.net> wrote:

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
newsu4g47hb9cpdv5tfb55thfscb6cjn7m6mn@4ax.com...

I have yet to see data, numbers, and reproduceable tests that
demonstrate memory effect. What I have seen are problems with
electrolyte loss, caused by overcharging and subsequent venting, that
mimick the problem. Incidentally, I found this by carefully weighing
the better before and after overcharging. It's not much loss, but
it's always present.

Reports on "memory effect" go back almost 50 years to the introduction of
cordless toothbrushes, which were commonly used briefly before being
recharged. They would (supposedly) lose capacity.

I don't know about electric tooth brushes, but I've had far too much
entertainment from 2way radio handhelds (HT's), pagers, cellphones,
and Norelco rechargeable shavers. The various radios and pagers were
all originally NiCd's and would tend to kill batteries far earlier
than my calculations would suggest. It didn't take long to find out
why. All of them overcharged in some manner. Most commonly, the
charge cycle was terminated by a timer that was based on the
characteristics of a brand new battery. That was fine for a new
radio, but would consistently overcharge (and overhead) an older
battery. An important clue is that a battery only overheats when over
charged. The brand new batteries would rarely get warm. The older
batteries would get rather hot.

Keeping my Norelco shaver batteries alive was an adventure. It stated
when I bought a used (cheap) cordless shaver at a garage sale. I
replace the batteries (Sub-C NiCd with new cells and noticed that the
shaver was warm after charging. After about a year, the batteries
were dead and I had only charged it perhaps 20 times. Some
measurements found that the charge controller was simply a fixed
resistor running at about 0.2C. There was no end of charge circuit,
and it would just continue overcharging. I later found a 950RX
shaver, which I use erratically today, that has an LCD bar graph to
indicate state of charge. Surely this shaver has an end of charge
detector. Nope. 0.2C at any charge level. I killed a set of
batteries after 2 years, which I guess is an improvement.

My experiences with power tools (mostly older Makita) is a mix. I
tend to do better with NiCd batteries because I have more of them and
because I tend to charge before every use. The greater number of
charge cycles of NiCd makes it a winner over NiMH.

Then people whose toothbrushes were accidentally activated in their luggage
and thoroughly run down recovered most of their capacity (the toothbrushes,
not the people). GE supposedly discovered the cause of memory effect
(electrode crystallization), but no cells that addressed the problem were
ever manufactured, that I know of.

If my rapidly failing memory serves me correctly, NiCd was going out
of fashion because of concerned over Cadmium in the water supply and
that NiMH was the recommended ecologically correct replacement.


--
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

 

[Steve Stone]

On 8/14/2011 10:23 AM, William Sommerwerck wrote:

"Steve Stone"<spfleck@citlink.net> wrote in message
news:AoQ1q.578798$SG4.192441@newsfe03.iad...

I have had good luck with LSD NiMH, like the Sanyo Eneloop
for use in cameras and two-way-radio gear.

Do you use them when you go on trips?


Yes