Jan,
The large 26650 cell may be a little large for your makitas, but there is
a smaller cell. Check here for sizes:http://www.a123systems.com/cms/product/
http://www.a123systems.com/cms/product/pdf/1/_ANR26650M1A.pdf
You would need 3 (or 4 cells) to give you an average 10V (or 13.2V) pack. A 4
cell pack can actually be directly charged from a cigarette lighter in about
15min with nothing more than small resistor in series while car runs. (14.4V Pb
charge voltage is ideal) . You don't need special temp sensor or anything for
rapid charge,only limit is voltage must be kept under ~3.8v/cell and current
not ridiculous <20A say. My guess is 3 cell pack is as good or better than "12V
ni-cds" and will last longer than drill, provided you never really deep
discharge it.
You ideally want to use a balancing charger at least once in a while. The RC
groups have lots of recomendations and there are really good cheap chinese
chargers aimed at rc modelers, that now handle LiFePO4 as well as all other
li-Co,Nimh etc and they will do balancing. You must make up an extra small
connector going to the cell taps for balancing.
Tim Hughes
--- On Sun, 12/19/10, Jan Steinman <Jan@xxxxxxxxxxxxxx> wrote:
> From: Jan Steinman <Jan@xxxxxxxxxxxxxx>
> Subject: Re: [OM] Battery types [was - iPods from Apple]
> To: olympus@xxxxxxxxxxxxxxxxx
> Date: Sunday, December 19, 2010, 10:04 AM
> > From: Hughes <hi100@xxxxxxxxxxxxx>
> >
> > The Newer LiFePO4 are truly
> outstanding, particularly the "nano-technology" ones
> (A123)...
>
> Do these have any particular charging requirements, or can
> you stick them on a stock Liion charger?=
>
> > 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.
>
> Sounds like a special charger, or at least a
> heat-sensing/regulating charger.
>
> > 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.
>
> Sounds like fun. I'll have to get some to play with. My
> trusty old 12V Makita drill has three packs that need
> rebuilding.
>
> ----------------
> Cross a mink with an octopus and you'll get a coat of arms.
> -- Lawrence Wasser
> :::: Jan Steinman, EcoReality Co-op ::::
>
> --
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>
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