It seems the DeWalt "12v" types are sometimes called 10.8v...
>
http://www.google.co.uk/products/catalog?hl=en&q=dewalt+10.8v&rlz=1I7GGLL_en&um=1&ie=UTF-8&cid=13340342462612542219&ei=HFAPTZWRKcWs8QOk9qiDBw&sa=X&oi=product_catalog_result&ct=result&resnum=1&ved=0CC0Q8wIwAA#
>
Jez
On 20 December 2010 13:37, Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>wrote:
> Thanks. I'm not sure what I was looking at before but 5 x 3.6 volts
> makes a lot more sense for an 18 volt pack.
>
> Chuck Norcutt
>
>
> On 12/20/2010 5:55 AM, Tim Hughes wrote:
> > 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 ::::
> >>>>>>
> >>>>> --
> >>>>>
> >>>
> >> _________________________________________________________________
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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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