DM51
Flashaholic
It does no harm to report a post you suspect, even if you are not sure about it. In this case you were right to suspect it, and I have deleted it. He has been posting fluff adverts everywhere, and he's now been banned.
NiCd still used in cordless drills Batterys
- Thread starter TinderBox (UK)
- Start date
Help Support Candle Power Flashlight Forum
half-watt
Flashlight Enthusiast
DM51, many thanks for taking the time to Post back and educate me. i know that i'm slow on the uptake, but i hope to get the hang of the rules before the end of my second(!!!) year on CPF!
This page on BatteryUniversity may be useful.
NiCd
QUOTE:
Advantages
Fast and simple charge, even after prolonged storage.
High number of charge/discharge cycles - if properly maintained, nickel-cadmium provides over 1000 charge/discharge cycles.
Good load performance - nickel-cadmium allows recharging at low temperatures.
Long shelf life - five-year storage is possible. Some priming prior to use will be required.
Simple storage and transportation - most airfreight companies accept nickel-cadmium without special conditions.
Good low temperature performance.
Forgiving if abused - nickel-cadmium is one of the most rugged rechargeable batteries.
Economically priced - nickel-cadmium is lowest in terms of cost per cycle.
Available in a wide range of sizes and performance options - most nickel-cadmium cells are cylindrical.
Limitations
Relatively low energy density.
Memory effect - nickel-cadmium must periodically be exercised (discharge/charge) to prevent memory.
Environmentally unfriendly - nickel-cadmium contains toxic metals. Some countries restrict its use.
Relatively high self-discharge - needs recharging after storage
UNQOTE
NiMH
QUOTE:
Advantages
30-40% higher capacity than standard nickel-cadmium. Nickel-metal-hydride has potential for yet higher energy densities.
Less prone to memory than nickel-cadmium - fewer exercise cycles are required.
Simple storage and transportation - transport is not subject to regulatory control.
Environmentally friendly - contains only mild toxins; profitable for recycling.
Limitations
Limited service life - the performance starts to deteriorate after 200-300 cycles if repeatedly deeply cycled.
Relatively short storage of three years. Cool temperature and a partial charge slows aging.
Limited discharge current - although nickel-metal-hydride is capable of delivering high discharge currents, heavy load reduces the battery's cycle life.
More complex charge algorithm needed - nickel-metal-hydride generates more heat during charge and requires slightly longer charge times than nickel-cadmium. Trickle charge settings are critical because the battery cannot absorb overcharge.
High self-discharge - typically 50% higher than nickel-cadmium.
Performance degrades if stored at elevated temperatures - nickel-metal-hydride should be stored in a cool place at 40% state-of-charge.
High maintenance - nickel-metal hydride requires regular full discharge to prevent crystalline formation. nickel-cadmium should be exercised once a month, nickel-metal-hydride once in every 3 months.
UNQUOTE
NiCd
QUOTE:
Advantages
Fast and simple charge, even after prolonged storage.
High number of charge/discharge cycles - if properly maintained, nickel-cadmium provides over 1000 charge/discharge cycles.
Good load performance - nickel-cadmium allows recharging at low temperatures.
Long shelf life - five-year storage is possible. Some priming prior to use will be required.
Simple storage and transportation - most airfreight companies accept nickel-cadmium without special conditions.
Good low temperature performance.
Forgiving if abused - nickel-cadmium is one of the most rugged rechargeable batteries.
Economically priced - nickel-cadmium is lowest in terms of cost per cycle.
Available in a wide range of sizes and performance options - most nickel-cadmium cells are cylindrical.
Limitations
Relatively low energy density.
Memory effect - nickel-cadmium must periodically be exercised (discharge/charge) to prevent memory.
Environmentally unfriendly - nickel-cadmium contains toxic metals. Some countries restrict its use.
Relatively high self-discharge - needs recharging after storage
UNQOTE
NiMH
QUOTE:
Advantages
30-40% higher capacity than standard nickel-cadmium. Nickel-metal-hydride has potential for yet higher energy densities.
Less prone to memory than nickel-cadmium - fewer exercise cycles are required.
Simple storage and transportation - transport is not subject to regulatory control.
Environmentally friendly - contains only mild toxins; profitable for recycling.
Limitations
Limited service life - the performance starts to deteriorate after 200-300 cycles if repeatedly deeply cycled.
Relatively short storage of three years. Cool temperature and a partial charge slows aging.
Limited discharge current - although nickel-metal-hydride is capable of delivering high discharge currents, heavy load reduces the battery's cycle life.
More complex charge algorithm needed - nickel-metal-hydride generates more heat during charge and requires slightly longer charge times than nickel-cadmium. Trickle charge settings are critical because the battery cannot absorb overcharge.
High self-discharge - typically 50% higher than nickel-cadmium.
Performance degrades if stored at elevated temperatures - nickel-metal-hydride should be stored in a cool place at 40% state-of-charge.
High maintenance - nickel-metal hydride requires regular full discharge to prevent crystalline formation. nickel-cadmium should be exercised once a month, nickel-metal-hydride once in every 3 months.
UNQUOTE
MrAl
Flashlight Enthusiast
Hi again,
When comparing cells of one type to cells of another type i have to recommend
that we stick to the same size cell (physically) unless there is another combination
of another type of cell that takes up the same size.
For example, if we want to compare NiCd to NiMH and we are looking at a sub C
size for NiCd, then we should also look at a sub C size for NiMH, not a D size.
This is true unless somebody comes out with a one half size sub C size, where you
could fit two in the same space as a sub C size, and then we should compare two
of them to one sub C NiCd. This should be logical enough.
The only catch to this is that it may not be possible to fit the two half size cells
in the same space as the full size cell because of the terminals and the way they
are connected. This could really be a problem with the tightly packed drill packs.
This would mean it's best to stick to the same size cell unless it has been tried
and proven that more smaller cells can fit in the same space.
Also, NiMH current ratings have increased over the years so im not sure if
we can still give NiCd the advantage there.
One little side note too is that when there is more space available it is possible
to go to a bigger cell, such as in my shaver. I was able to modify the physical
design so that i could fit bigger NiMH cells where the little (i should say tiny)
NiCd's once lived. That little shaver really buzzes now
but the cells die
after about 5 or 6 months and have to be replaced.
It makes sense that the unit would work better now because there are bigger
cells in it, but it would not be fair to say that the larger NiMH cells are better
than the smaller NiCds, or rather that NiMH cells are better than NiCds just
because the larger size cells worked better. Im sure most people can understand
this reasoning.
Another side note to think about is that sometimes it is possible to change
something about the phyiscal design that was not intended in the original
product and thus obtain a ten fold usefulness of the product. The example
here is when i started having trouble with my drill packs (dying way too soon)
i looked for other ways to power the drill. One way i found beat all others.
The new idea was to take an old drill pack (with NiCds) and remove all of
the cells completely, and hook up some heavy gauge wire to where the
terminals connect to the drill itself. This meant that when i snapped in
this new drill pack there would be only two wires connected to the motor
of the drill, where the NiCds used to connect to.
Next, i put a cigar lighter plug on the other end of the heavy wires.
Now, if the drill pack goes dead (which it never does now since i redesigned
the charger too) i simply plug the empty drill pack into the drill and plug the
cigar plug into my 12v automobile jump pack (sold in various places like
Home Depot, Pep Boys, everywhere else too just about). These jump packs
have a hefty 12v sealed Lead Acid battery inside, and hold much more charge
than any sub C or even D cells can hold. The run time is probably hours but
i've never had to use it that long at one time.
This is only an example however, as i have another drill that is awaiting a
heavy connector where the charger might have plugged into the drill body,
where i intend to mount a connector that will be used to plug this into the
jump pack too.
Of course other ideas would work great too, like building your own Li-ion
pack to power the drill, and connect it via a heavy wire and maybe a
connector or two. Im sure larger NiMH cells would work too, as long as
the cells are charged with a charger made to charge NiMH cells.
Come up with your own ideas for a new pack too, like perhaps one that
fits on a shoulder harness and connects to the drill with heavy wires,
or maybe a belt mounted battery pack, also connecting with wires.
Just to note, i dont find the wire to get in the way at all. The main
thing is to be able to take the drill where no 120vac outlet is available,
not to get rid of the wire entirely.
Good luck...
When comparing cells of one type to cells of another type i have to recommend
that we stick to the same size cell (physically) unless there is another combination
of another type of cell that takes up the same size.
For example, if we want to compare NiCd to NiMH and we are looking at a sub C
size for NiCd, then we should also look at a sub C size for NiMH, not a D size.
This is true unless somebody comes out with a one half size sub C size, where you
could fit two in the same space as a sub C size, and then we should compare two
of them to one sub C NiCd. This should be logical enough.
The only catch to this is that it may not be possible to fit the two half size cells
in the same space as the full size cell because of the terminals and the way they
are connected. This could really be a problem with the tightly packed drill packs.
This would mean it's best to stick to the same size cell unless it has been tried
and proven that more smaller cells can fit in the same space.
Also, NiMH current ratings have increased over the years so im not sure if
we can still give NiCd the advantage there.
One little side note too is that when there is more space available it is possible
to go to a bigger cell, such as in my shaver. I was able to modify the physical
design so that i could fit bigger NiMH cells where the little (i should say tiny)
NiCd's once lived. That little shaver really buzzes now
but the cells dieafter about 5 or 6 months and have to be replaced.
It makes sense that the unit would work better now because there are bigger
cells in it, but it would not be fair to say that the larger NiMH cells are better
than the smaller NiCds, or rather that NiMH cells are better than NiCds just
because the larger size cells worked better. Im sure most people can understand
this reasoning.
Another side note to think about is that sometimes it is possible to change
something about the phyiscal design that was not intended in the original
product and thus obtain a ten fold usefulness of the product. The example
here is when i started having trouble with my drill packs (dying way too soon)
i looked for other ways to power the drill. One way i found beat all others.
The new idea was to take an old drill pack (with NiCds) and remove all of
the cells completely, and hook up some heavy gauge wire to where the
terminals connect to the drill itself. This meant that when i snapped in
this new drill pack there would be only two wires connected to the motor
of the drill, where the NiCds used to connect to.
Next, i put a cigar lighter plug on the other end of the heavy wires.
Now, if the drill pack goes dead (which it never does now since i redesigned
the charger too) i simply plug the empty drill pack into the drill and plug the
cigar plug into my 12v automobile jump pack (sold in various places like
Home Depot, Pep Boys, everywhere else too just about). These jump packs
have a hefty 12v sealed Lead Acid battery inside, and hold much more charge
than any sub C or even D cells can hold. The run time is probably hours but
i've never had to use it that long at one time.
This is only an example however, as i have another drill that is awaiting a
heavy connector where the charger might have plugged into the drill body,
where i intend to mount a connector that will be used to plug this into the
jump pack too.
Of course other ideas would work great too, like building your own Li-ion
pack to power the drill, and connect it via a heavy wire and maybe a
connector or two. Im sure larger NiMH cells would work too, as long as
the cells are charged with a charger made to charge NiMH cells.
Come up with your own ideas for a new pack too, like perhaps one that
fits on a shoulder harness and connects to the drill with heavy wires,
or maybe a belt mounted battery pack, also connecting with wires.
Just to note, i dont find the wire to get in the way at all. The main
thing is to be able to take the drill where no 120vac outlet is available,
not to get rid of the wire entirely.
Good luck...
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half-watt
Flashlight Enthusiast
there are high-discharge rate NiMH AA cells with 10C discharge rates almost equaling, to best of my knowledge, NiCd cells. IIRC, their capacity is significantly lower though than the "best in class", so to speak, NiMH AA cells (e.g. Sanyo 2700 NiMH AA cells), at least the only ones i've seen are under 2000mAh. IIRC, high quality, more mainstream NiMH AA cells are more like a 5C rate max for short periods of time, and 1C to 2C more like the recommended discharge rates.
[Note to self: this now makes me think of the cells in my hybrid auto? wonder what the max discharge rate is for them? i'll have to remember to investigate this.]
we need to remember that as the continuous discharge increases, accessible capacity will decrease for [nearly???] any chemistry due to the heat generated by them lil' 'trons flowing.
EDIT:
'nuff of my decrepit old memory. here is a Wiki quote fr/its entry on NiCd batteries: "In addition, like alkaline batteries, NiMH batteries experience a voltage drop as it nears full discharge, which a NiCd does not. Finally, a similarly-sized NiCd battery has a slightly lower internal resistance, and thus can achieve a higher maximum discharge rate (which can be important for applications such as power tools)."
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Half-watt, wow! you seem to have written an entire essay there but I'm not sure that was quite necessary. I'm well aware of the meanings of the physical quantities; Energy, capacity, current, voltage and power and I'm not arguing with any of your points except this one:
I never implied that I knew the answer to this for sure but just that I was under the impression that this was no longer true.
I know that in the RC community, when NiMh had just emerged they were slow in adopting the new technology, which was probably for this very reason. But as capacities of NiMh increased, so did the current handling and I was under the impression that they had exceeded NiCd due to the fact that all the RC people had switched to NiMh and never looked back. OK, you could argue that this is because of lack of development of NiCd, but this is irrelevant.
I refuse to concede this point until I see test results of the best NiCd against best NiMh for common battery sizes. A possibly outdated wiki entry doesn't prove anything.
Common sizes would include AA, Sub C (RC cars) and 2/3 A (RC Planes)
I'd also like to see some tests of that 20A NiCd AA that you mentioned.
I never implied that I knew the answer to this for sure but just that I was under the impression that this was no longer true.
I know that in the RC community, when NiMh had just emerged they were slow in adopting the new technology, which was probably for this very reason. But as capacities of NiMh increased, so did the current handling and I was under the impression that they had exceeded NiCd due to the fact that all the RC people had switched to NiMh and never looked back. OK, you could argue that this is because of lack of development of NiCd, but this is irrelevant.
I refuse to concede this point until I see test results of the best NiCd against best NiMh for common battery sizes. A possibly outdated wiki entry doesn't prove anything.
Common sizes would include AA, Sub C (RC cars) and 2/3 A (RC Planes)
I'd also like to see some tests of that 20A NiCd AA that you mentioned.
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half-watt
Flashlight Enthusiast
a simple web search produces many links which maintain the same main point i've been tryin' to make, viz. NiCd chemistry can supply higher continuous levels of current than NiMH chemistry. if you don't want to take the time to search the WWW, then just Google "Green Batteries" (that's one of the "hits" i recall Google locating). they sell cells and, IIRC, they maintain this same point as well. there were others, but you'll value the learning experience more if you get your info fr/another source than myself.
as to the second point quoted above, while NOT a "test", found this...
"The maximum discharge rate for a NiCd battery varies by size. For a common AA-size cell, the maximum discharge rate is approximately 18 amps; "
it's from that same "outdated", as you termed it, Wiki article. if it's outdated, maybe it's higher than 18A now??? don't know. if not, then please recall my precise words which were "somewhere around twice". i chose to phrase it that way b/c i couldn't remember a precise number. my apologies for my ~11% error. i didn't mean to mislead you or anyone else reading that Post of mine. i would hope that 18A is "somewhere around twice" (close enough for Gov't work maybe???) the 10A that you mentioned Eneloops can "easily handle".
you really got my interest up w/the "easily handle" 10A number for AA Eneloops. so, i just had to search the Net. as i searched, even though i rcv'd many hits about Eneloops, i couldn't find anything about AA Eneloops being able to easily supply continuous 10A. i did find one 5C short duration reference (unfortunately none i read, even on the Sanyo website, quantified the time period for this 10A draw). however, most references discouraged anything over a 1C, 2C, and one reference mentioned 3C continuous discharge rate. i'd like to learn more, do you have a link? i'm assuming that you meant continuous 10A supply since you didn't specify an intermittent burst rate of some sort. was i mistaken in assuming this? furthermore, i'm guessing that these 10A discharge rates don't do any damage to the cell since it is "easily" handled. please keep in mind NiCd's can supply high rates for extended periods of time unlike short duration 5C draws.
well, i'm going to head back out into the "ether" searching for more info on NiMH and NiCd chemistry. the subject of batteries has always fascinated me. looks like i need to find more up to date info. i definitely needed to get up to date last year when SilverFox pointed out that my Li-ion info was out of date and no longer valid. maybe SF knows about NiCd and NiMH cells also? SF, if you read this, please educate us fr/your Encyclopedic knowledge of cells/batteries.
if you get a chance, i'd really like a link to that source of yours. many thanks, pj aka half-watt
MrAl
Flashlight Enthusiast
Hi there,
Well, i guess i am guilty here of being a bit biased on talking "NiMH" yet thinking
"NiMH sub C". I think this is because i dont see a need for NiCd AA's anymore,
at least not for anything i use, and also because Sub C is the size used
in the drill packs i've seen.
I also have to say that it has been quite a while since i checked some specs
on both NiCd and NiMH sub C size cells, and i think this is what we (someone here)
should do. Look up some sub C size cells and see what we find out. I know NiMH
specs are a little higher than they used to be (current draw) so this would be a
good idea. We can then determine if the NiMH would be better, and if so, just
how much better, or if worse, just how much worse. We will assume that a
charger that can do NiMH properly is going to be used.
I have to agree, sorry to say, that some Wiki entries could be out of date, and
with the one quoted (unfortunately) it is plainly outright wrong (incorrect) about
one of the facts about the NiCd cell. I'll quote here again just for quick reference:
Although it has (in the past) been true that the NiCd's have given a higher rate of
discharge (current), the NiMH cells may be catching up (this is why i think we should
check the most recent specs on some decent quality sub C NiMH cells and compare
to NiCd of same size), what is plainly incorrect is the statement:
"In addition, like alkaline batteries, NiMH batteries experience a
voltage drop as it nears full discharge, which a NiCd does not."
This is false, in that modern NiCd cells *do* in fact experience a voltage drop
as they near full discharge (proper current level of course, just like NiMH). Because
of this i cant help but bring the whole paragraph into question.
Also, i dont see a date reference so we dont know how old this statement is.
If we had to judge the date based on the data presented there, we would have
to guess that it was written a long time ago when some NiCd's did not experience
the voltage drop, if we dont take the whole thing as a gross error on the part of
the writer.
CNC Dan
Enlightened
I have had two 12v DeWalt re-celled at primecell.com with good results.
I also use a 14v pack with my 12v drill. I had to modify the drill to take the slightly diferent shape of the 14v pack.
half-watt
Flashlight Enthusiast
Mr. Al, i think NiMH cells actually do experience that voltage drop at moderate to high current draws. the drop occurs, IIRC, somewhere as high as 90% of charge depletion, i.e. 10%SOC (though i've seen curves where it begins to happen as low as 80% depleted, or 20%SOC, but i think these were older curves, IIRC). this voltage drop-off can be seen in the characeristic discharge curve for NiMH chemistry.
NiCd's can go a bit longer (90% to even 95%) before they very quickly "fall off a cliff", so to speak, the drop off can be so fast.
also, i've been discussing AA cells. can't say that i have anything to say about sub-C cells. never used any.
you might find of interest my other Post where i mention AA high-discharge rate NiMH cells. some can apparently equal the 18A discharge rate of AA NiCd cells if AA NiCd's cells haven't iimproved any in the last few years. for how long these special NiMH cells can supply this much current i don't know. unfortunately, the capacity of these AA high-discharge cells is significantly less than the best NiMH cells (at least the ones i read about some time back). guess we don't get somethin' for nuttin'.
lastly, i guess by "out of date" you mean within the last five years or so as the article is less than 5.5yr old? have NiCd's changed that much in the last 5yr?
BTW, other than in cordless power tools, i no longer own or use any NiCd cells or batteries. i much prefer NiMH cells to NiCd.
NiCd's can go a bit longer (90% to even 95%) before they very quickly "fall off a cliff", so to speak, the drop off can be so fast.
also, i've been discussing AA cells. can't say that i have anything to say about sub-C cells. never used any.
you might find of interest my other Post where i mention AA high-discharge rate NiMH cells. some can apparently equal the 18A discharge rate of AA NiCd cells if AA NiCd's cells haven't iimproved any in the last few years. for how long these special NiMH cells can supply this much current i don't know. unfortunately, the capacity of these AA high-discharge cells is significantly less than the best NiMH cells (at least the ones i read about some time back). guess we don't get somethin' for nuttin'.
lastly, i guess by "out of date" you mean within the last five years or so as the article is less than 5.5yr old? have NiCd's changed that much in the last 5yr?
BTW, other than in cordless power tools, i no longer own or use any NiCd cells or batteries. i much prefer NiMH cells to NiCd.
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Lots of NiMh tested by silverfox here
Just use control f to find "eneloop" It's only tested up to 10A though.
I've just noticed the "Titanium Power Max AA" (NiMh) on the same page. It shows a 20A discharge curve in which the capacity only drops to 1244mAh.
half-watt
Flashlight Enthusiast
MB, many thanks for the link. i'll check it in a moment. there ought to be some good info there from Tom.
thanks for mentioning the word "Titanium". you jogged my memory. those were the ones that i was thinking of. 20A probably exceeds their recommended limit which, IIRC, was 18A - but, i don't know if that was continuous or relatively short duration draw. 20A could damage the cell and adversely affect its future use perhaps???
again, many thanks for the link.
thanks for mentioning the word "Titanium". you jogged my memory. those were the ones that i was thinking of. 20A probably exceeds their recommended limit which, IIRC, was 18A - but, i don't know if that was continuous or relatively short duration draw. 20A could damage the cell and adversely affect its future use perhaps???
again, many thanks for the link.
half-watt
Flashlight Enthusiast
dbl-Post. experiencing lots of "timeouts" on page loads and both Posting and Editing Posts. i think the two are related in some way???
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Mr Happy
Flashlight Enthusiast
Silverfox has posted some discharge test graphs for various AA NiMH cells at different currents here on this very forum (sorry, can't immediately point to a link).
Eneloops do indeed come out well in terms of holding their voltage at high discharge currents, but on reviewing those graphs I reached the a conclusion that 5 A was a reasonable maximum to aim for. While Eneloops can supply 10 A, the voltage starts to drop quite significantly at that rate.
We're one step ahead of you read posts #31 and #32. Ok, I think we've established that NiCd is probably better on average but what I would like to compare is the best of NiCd vs the best of NiMh (In terms of current).
The best NiMh AA seems to be the Titanium Power max AA
Does any one know what the best NiCd AA is?
Then there's Sub C and 2/3 A to compare which are the common battery pack sizes.
read posts #31 and #32. Ok, I think we've established that NiCd is probably better on average but what I would like to compare is the best of NiCd vs the best of NiMh (In terms of current).The best NiMh AA seems to be the Titanium Power max AA
Does any one know what the best NiCd AA is?
Then there's Sub C and 2/3 A to compare which are the common battery pack sizes.
Sub_Umbra
Flashlight Enthusiast
OK, so you want to compare Titanium Power max AA...to something...er...that you know nothing about. So that takes us right back to apples and oranges...We're one step ahead of you
inatly
The best NiMh AA seems to be the Titanium Power max AA
Does any one know what the best NiCd AA is?...
The bottom line is that NiMH chemistry definitly has a higher charge resistance than NiCD (requires a higher charge voltage than NiCD) and I'll bet NiMH also have a slightly higher discharge resistance which means, to me at least, that your whole argument is an artificial construct and has no significant bearing in real world applications -- even though you may actually be correct....in some example that you are unable, at this time, to supply.
To argue that a Titanium Power max AA may discharge a greater current than some unnamed NiCD cell that you've never even considered has about as much substance as speculating about, "How many angels may dance on the head of a pin".
Also, what do Titanium Power max AAs have to do with the Subject's "cordless drills Batterys"? Or any powertool battery packs?
Sounds like it could be an interesting new thread -- but here it's more like troll bait.
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Molicell presents a higher technology with more output and cycles (1200) and safer operation using neither NiCd or NiMh.
NiCd versus NiMh very interesting that NiCd is still going strong and Molicell has this to say of the pace of technology overtaking NiCd for tools.
They are located in the Vancouver, B.C. area and as they have sales and distribution in Canada you can check out on the excerpt below and cruise the links.
Power cell（LiMn2O4）
NiCd versus NiMh very interesting that NiCd is still going strong and Molicell has this to say of the pace of technology overtaking NiCd for tools.
They are located in the Vancouver, B.C. area and as they have sales and distribution in Canada you can check out on the excerpt below and cruise the links.
E-One Moli Energy was the first company to introduce the Li-Ion cell (power cell) in the construction-grade cordless power tool market. It was a revolutionary break through in the power tool world. With spinel LiMn2O4 chemistry, high-power cells have longer run time, lighter weight, and more power, and have gradually replaced standard NiCd cells. Most importantly, in multi-cell applications, these cells have higher safety and stability, which is especially suitable for power tools and electric vehicles.
Notice to Readers - In order to ensure a safe battery pack, the use of a properly designed safety circuit is essential. MOLICEL® lithium-ion cells are not sold as "bare cells" to consumers. The cells are required to be assembled into battery packs by authorized pack assemblers. Authorized pack assemblers have knowledge of safe lithium-ion pack and circuitry design and employ proper assembly techniques.
http://www.molienergy.bc.ca/products.html
http://www.e-one.com.tw/
Hope it's useful
marlite
Notice to Readers - In order to ensure a safe battery pack, the use of a properly designed safety circuit is essential. MOLICEL® lithium-ion cells are not sold as "bare cells" to consumers. The cells are required to be assembled into battery packs by authorized pack assemblers. Authorized pack assemblers have knowledge of safe lithium-ion pack and circuitry design and employ proper assembly techniques.
http://www.molienergy.bc.ca/products.html
http://www.e-one.com.tw/
Hope it's useful
marlite
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I thought it was clear that I already conceded that point and was now trying to compare the best of each chemistry. This is not an artificially constructed argument; someone wanting to design a battery pack for cordless tools would want to choose the best available cells and not stick to any particular chemistry because it's better on average.
I never claimed that to be the case nor did I say initially that I knew the answer for sure.
Some battery packs use AAs (I own a Bosch cordless drill where the pack consists of 20 x AA cells) so it is relevant, other common sizes include Sub C and 2/3A as I mentioned.
This is not trolling, as I've just explained, everything I said was relevant.
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half-watt
Flashlight Enthusiast
Sub, i agree 100% w/you on the technical points you made re: NiCd v. NiMH. thank you for Posting your excellent thoughts. you've expressed much more clearly and succinctly than i could or did the cases for these two chemistries. thank you again.
also, since it was brought up, and since most of the interaction which expressed a diff in opinion was b/t MB and myself, i feel the need to say that i NEVER felt that MB was trolling - at least as far as i was concerned.
fr/my perspective MB and i were having a pleasant and educational disagreement. he really helped me recall the name of the Titanium high-discharge rate NiMH cells. i don't know anyone who uses them though - they might be nice in a hot-wire though??? perhaps???. their lower capacity and shorter burntime when that very high discharge current is NOT required makes them a poor choice as compared to some other higher capacity NiMH cells. i think that for MOST practical purposes on CPF, we can ignore these cells. who actually used them in a flashlight? especially a LED light. anyone? maybe some Milky Project-M w/a gazillion Cree's crammed into a light? [i think i'm gonna' have to eventually get a Project-M and some of those Max Power NiMH cells].
Sub, thank you for coming to my assistance in helping to explain the facts about these two chemistries. i truly appreciate it. i just mentioned the "trolling" issue b/c i don't want anyone to think that, purely fr/my perspective - i can't speak for others, that any "trolling" was perceived (by me, at least).
take care. sincerely, pj aka half-watt
also, since it was brought up, and since most of the interaction which expressed a diff in opinion was b/t MB and myself, i feel the need to say that i NEVER felt that MB was trolling - at least as far as i was concerned.
fr/my perspective MB and i were having a pleasant and educational disagreement. he really helped me recall the name of the Titanium high-discharge rate NiMH cells. i don't know anyone who uses them though - they might be nice in a hot-wire though??? perhaps???. their lower capacity and shorter burntime when that very high discharge current is NOT required makes them a poor choice as compared to some other higher capacity NiMH cells. i think that for MOST practical purposes on CPF, we can ignore these cells. who actually used them in a flashlight? especially a LED light. anyone? maybe some Milky Project-M w/a gazillion Cree's crammed into a light? [i think i'm gonna' have to eventually get a Project-M and some of those Max Power NiMH cells].
Sub, thank you for coming to my assistance in helping to explain the facts about these two chemistries. i truly appreciate it. i just mentioned the "trolling" issue b/c i don't want anyone to think that, purely fr/my perspective - i can't speak for others, that any "trolling" was perceived (by me, at least).
take care. sincerely, pj aka half-watt
half-watt
Flashlight Enthusiast
those were very nice graphs. a lot of work sure went into them. they are priceless, IMO.
i too questioned whether such high discharge rates were wise. now, for testing purposes fine. but, for actual use in an application which would often or always draw such currents, IMO, this would be unwise (not that SF was necessarily advocating such use regularly).
unless Tom mentioned such (and perhaps i missed it skimming the plots and Post), i wouldn't want to assume that Tom was advocating daily use of Eneloops at 5C (10A) discharge rates. i would want to personally query him on this point if i intended to use Eneloops (or any of the non-Ti Power Max NiMH cells) daily at such high discharge rates. which i don't; so i won't [query him].
i naively, since i haven't performed any life testing under these conditions, believe that such use regularly would DRASTICALLY shorten the cells' life and degrade its performance quickly.
however, that said, it is known that NiCd's form crystals (this is NOT a good thing) and that high discharge rates break up those crystals (this is a good thing). don't know enough about NiMH to know if this similar phenonmenon occurs in NiMH.
i thank those who have taken of their time to dialog w/me in this Thread, especially my thanks to MB. i perceive, perhaps erroneously, based upon some wording of his replies that i may have come across a bit rough on him. no offense was intended; i hope none was taken. however, if i did give offense, then i sincerely apologize to you, MB. i thoroughly enjoyed our dialog. thank you.
finally, i don't have anything else substantive to offer this Thread that i haven't already tried to communicate and so will probably stop Posting in it now. however, i for one would greatly appreciate SF's input here. Tom, you copy?
