Chuck,
ok I went and checked the dewalt website this dewalt 18V pack has 10
smaller size A123 cells , so here they paralleled 5 pairs of cells to make the
pack a little more compact:
http://dewaltownersgroup.com/index.php?PHPSESSID=d886b14708b013d8bdc7af2fbf9af5f6&topic=168.0
this 12V dewalt is likely sony lifepo4 cells, but can't be sure, no label:
http://dewaltownersgroup.com/index.php?PHPSESSID=d886b14708b013d8bdc7af2fbf9af5f6&topic=387.0
The rc model groups have reallly good information on dissecting/using the
dewalt nano-packs for other purposes.Including 10min charging, abusive cycling
etc.
Tim Hughes
--- On Mon, 12/20/10, Tim Hughes <timhughes@xxxxxxxx> wrote:
> From: Tim Hughes <timhughes@xxxxxxxx>
> Subject: Re: [OM] Battery types [was - iPods from Apple]
> To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
> Date: Monday, December 20, 2010, 1:57 AM
> Chuck,
> I am not sure which of packs you are
> looking at, as the dewalt line includes many types NiCd
> (old) ,NiMh,LiFePO4 (A123) and I believes some other
> technology Li-ion cells now too (maybe Sony) in its cheaper
> Li line. The website is quite good because it identifies
> cells used in quite a few vendors products.
>
> The VPX line from Black and decker use A123 nano-cells,
> but it is a smaller size 1.1Ah cells.
>
> At the 18V pack level I believe you can use both the NiMH
> packs or the LiFePO4 packs interchangeably in the 18V Dewalt
> tools and they even have multifunction intelligent chargers
> that handle both types.
>
> I seem to remember they have a lightweight Li pack and a
> heavy weight pack at 18V one using 5x 2.3Ah cells and one
> using 5x 1.1Ah cells.
> here are cell specs, download data sheet:
> http://www.a123systems.com/a123/products ; the
> 2.3Ah cell is model 26650
>
> The Dewalt 36V 2.2Ah packs are the most popular for
> dissection or use in electric scooters etc. These contain 10
> cells. Typically you can get them new for ~$100 off ebay
> with patience. If you short the cell while dissembling, you
> can literally vaporize the thick metal tab. The actual
> voltage per cell averages more like ~3.3V . So an 18V pack
> is actually about 16.5V in use, but due to the low impedance
> is more constant under heavy load than say a NiMh.
>
> Just off charge the cells are about 3.55V or just under 18V
> for pack. The common lithium ion etc batteries in laptops
> are just under 4.2V coming off charge, but average a bit
> higher voltage than LiFePO4,something like 3.5V or even 3.6
> depending on particular chemistry. The energy density
> advantage of regular Li-cells, even at low rates, soon fades
> as the cells automatically lose ~20% pa if kept fully
> charged and lose even more when cycled. Cycle life is 5 to
> 10 times worse and self discharge is much higher for Li-Co
> laptop type cells.
>
> Tim Hughes
>
>
> --- On Sun, 12/19/10, Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
> wrote:
>
> > From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
> > Subject: Re: [OM] Battery types [was - iPods from
> Apple]
> > To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
> > Date: Sunday, December 19, 2010, 6:24 AM
> > Interesting. But I was confused
> > by the DeWalt link which appears to
> > show a 12 volt battery with 3 cells and an 18 volt
> battery
> > with 6 cells.
> > Aren't all of these rechargeable lithium
> chemistries
> > nominally 3.2
> > volts/cell?
> >
> > Chuck Norcutt
> >
> >
> > On 12/19/2010 3:22 AM, Hughes wrote:
> > > Chuck, The Newer LiFePO4 are truly outstanding,
> > particularly the
> > > "nano-technology" ones (A123), although the new
> Sony
> > ones are a
> > > cheaper and reasonable alternative now apearing,
> but
> > not as high peak
> > > power. Dewalt unfortunately charges a hefty
> > premium for A123, but
> > > they are really worth it for high power
> professional
> > tools. You can
> > > get battery operated saws for example, as
> powerful as
> > line operated
> > > ones (1.5Hp). Black and Decker consumer VPX
> series,
> > also use A123
> > > cells for small devices.
> > >
> > > These have very Low self discaharge,very high
> peak
> > power, not as high
> > > energy density, but unlike normal Li-ion/poly
> they
> > will maintain
> > > power for years of abuse. I converted my Metz
> CT60
> > flashes to use
> > > them, and cut the weight to less than that of
> smaller
> > Oly CT45 for a
> > > more powerful 200J portable flash, with a larger
> > number of flashes
> > > too. Recharge in less than an hour.
> > >
> > > If you are into tinkering the small VPX packs are
> easy
> > to convert for
> > > use in lots of different equipment and can be
> bought
> > on ebay, at
> > > lower prices. I have a number of old small
> > screwdrivers,drills etc
> > > converted to use them. Just don't drain them
> right
> > down, keep a
> > > couple of packs and swap at first sign of
> slacking and
> > they will last
> > > and last. Some of the LiFePO4 packs now have
> > reasonable warrantys
> > > 2+years.
> > >
> > > To see how powerful and relatively abuse proof
> the
> > A123 cells are, go
> > > and read the RC helicopter websites where they
> abuse
> > these cells
> > > getting>250W from each large c-cell and then
> > recharging them in
> > > ~20minutes.
> > >
> > > This website has lots of info on the cells used
> in
> > different power
> > > tools mainly dewalt, but includes others:
> > > http://dewaltownersgroup.com/index.php?PHPSESSID=d886b14708b013d8bdc7af2fbf9af5f6&board=26.0
> > >
> > > Lots of people buy LiFePO4 cell drill/saw
> packs
> > for modifying, for
> > > all sorts of high power applications off of ebay.
> This
> > is often the
> > > cheapest way to get them if you want to convert
> your
> > old high power
> > > battery tools.
> > >
> > > Tim Hughes
> > >
> > > --- On Thu, 12/16/10, Bill Pearce<bs.pearce@xxxxxxx>
> > wrote:
> > >
> > >> From: Bill Pearce<bs.pearce@xxxxxxx>
> > Subject: Re: [OM] Battery
> > >> types [was - iPods from Apple] To: "'Olympus
> > Camera
> > >> Discussion'"<olympus@xxxxxxxxxxxxxxxxx>
> > Date: Thursday, December
> > >> 16, 2010, 2:02 PM I recently got a powered
> > screwdriver, a Bosch. It
> > >> says it has NiMH. It holds a charge for a
> really
> > long time and
> > >> lasts forever.
> > >>
> > >>
> > >>
> > >> From: Chuck Norcutt [mailto:chucknorcutt@xxxxxxxxxxxxxxxx]
> > >>
> > >> Sent: Thursday, December 16, 2010 1:57 PM
> To:
> > Olympus Camera
> > >> Discussion Subject: Re: [OM] Battery types
> [was -
> > iPods from
> > >> Apple]
> > >>
> > >>
> > >>
> > >> I think the perseverance of NiCd cells in
> certain
> > applications is
> > >> readily understandable in terms of the rate
> of
> > self discharge.
> > >> NiCd cells (until recently) have had much
> lower
> > self discharge
> > >> rates than NiMH cells. NiCD persists for a
> > walkie-talkie or
> > >> portable drill since you haven't been able
> to
> > count on an NiMH
> > >> powered device to have any charge left if
> you
> > haven't used it in
> > >> 3-6 months.
> > >>
> > >> But that all started to change recently.
> You
> > may recall the
> > >> announcement posted here the other day by
> Tim
> > Hughes concerning
> > >> three new types of NiMH batteries from Sanyo
> > Eneloop. The newest
> > >> cells promise 75% power after 3 years sitting
> on
> > the shelf. That's
> > >> probably better than NiCd, maybe even much
> > better.
> > >>
> > >> Also, I note that drill drivers are starting
> to
> > show up that have
> > >> lithium-ion batteries. The last I noticed
> > they were expensive
> > >> enough that I wasn't willing to replace my
> own
> > NiCD powered drill
> > >> but the next power tool purchase could be
> > something different.
> > >>
> > >> Chuck Norcutt
> > >>
> > >>
> > >> On 12/16/2010 12:54 PM, Jan Steinman wrote:
> > >>>> From: Moose<olymoose@xxxxxxxxx>
> > >>>>
> > >>>> On 12/15/2010 11:00 AM, Jan Steinman
> > wrote:
> > >>>>> Although it's open on my desktop,
> I've
> > not
> > >> looked at the
> > >>>>> BatteryUniversity.com site yet,
> but
> > my
> > >> understanding of classic
> > >>>>> NiCd is that repeated incomplete
> > discharging
> > >> to about the same
> > >>>>> level causes a crystalline
> precipitate
> > to form
> > >> at a certain
> > >>>>> location related to the
> discharge
> > depth,
> > >> therefore causing the
> > >>>>> mis-named "memory effect." (It
> should
> > really
> > >> be called the
> > >>>>> "forget effect." :-)
> > >>>>>
> > >>>>> Memory effect is not a problem
> when
> > the cell
> > >> is repeatedly
> > >>>>> discharged to different levels.
> > Classic case:
> > >> a cop runs a
> > >>>>> walkie-talkie for eight hours a
> day
> > and drops
> > >> it in the charger
> > >>>>> overnight -- bad news for NiCd
> cell
> > life. But
> > >> memory effect is
> > >>>>> not likely if you're using a
> flash or
> > motor
> > >> drive for various
> > >>>>> periods of time and then topping
> off
> > on a
> > >> charger.
> > >>>>
> > >>>> "Among rechargeable batteries,
> > nickel-cadmium
> > >> remains a popular
> > >>>> choice for two-way radios,"
> > >>>>
> > >>>> Since what you say here doesn't agree
> with
> > what's
> > >> on that site,
> > >>>> perhaps you might read it and resolve
> the
> > >> differences.
> > >>>
> > >>> Yea, I'll have to check that out, because
> it
> > doesn't
> > >> go along with my
> > >>> experience as a ham-radio operator, my
> work as
> > a
> > >> repair tech in a
> > >>> two-way communications shop, nor my stint
> as
> > an RF
> > >> engineer.
> > >>>
> > >>> I don't know of any hams who still use
> NiCd
> > cells in
> > >> their two-way
> > >>> radios, but note that the OEM battery
> packs
> > you get
> > >> from Icom for
> > >>> older radios still have them. Perhaps its
> just
> > because
> > >> NiCd's are
> > >>> still cheaper. (New hand-held ham gear
> is
> > almost all
> > >> lithium
> > >>> powered.)
> > >>>
> > >>> NiCds do have lower internal resistance
> than
> > NiMH,
> > >> which might make
> > >>> them preferable in high-current
> applications
> > -- like
> > >> photo strobes.
> > >>> But that wouldn't explain hand-held
> radios,
> > which have
> > >> relatively
> > >>> moderate current needs. And if they're so
> good
> > for
> > >> hand-helds, why
> > >>> don't you ever see them in cell phones?
> > Puzzle.
> > >>>
> > >>> But such fun has to wait. I have to go
> pick up
> > a buck
> > >> to romance our
> > >>> four Nubian goats today.
> > >>>
> > >>> Obligatory camera content: I need to take
> some
> > photos
> > >> of our
> > >>> zero-mile raw goat milk ice cream... if
> > there's any
> > >> left...
> > >>>
> > >>> ---------------- Religions are the great
> fairy
> > tales
> > >> of conscience.
> > >>> -- George Santayana :::: Jan Steinman,
> > EcoReality
> > >> Co-op ::::
> > >>>
> > >> --
> > >>
> >
> _________________________________________________________________
> > >> Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
> > >> Archives: http://lists.thomasclausen.net/mailman/private/olympus/
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> > >>
> > >> _____
> > >>
> > >> No virus found in this message. Checked by
> AVG -
> > www.avg.com
> > >> Version: 10.0.1170 / Virus Database: 426/3319
> -
> > Release Date:
> > >> 12/16/10
> > >>
> > >> --
> > >>
> >
> _________________________________________________________________
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> > >> Archives: http://lists.thomasclausen.net/mailman/private/olympus/
> > >> Themed Olympus Photo Exhibition: http://www.tope.nl/
> > >>
> > >>
> > --
> >
> _________________________________________________________________
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> >
> >
> --
> _________________________________________________________________
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>
>
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