Pasi T Mustalahti wrote:

> On Fri, 27 Mar 1998, Tony Abbey wrote:
> > Nigel Goodwin wrote:
> > >>I have another 'quick' question... Does anyone know how much power is
> > >>in an alkaline AA cell? It's 1.5V but what are the Amp/Hours?
>
> PTM: How much Ah's is in Lithium-Ion rechargeables compared to NiCd and
> how to charge them ? Has anybody cooked any kind of PIC based charger for
> them ?

The cell sizes and voltages are different for lithium ion and Nickel Cadmium

Here are some sample numbers, they are a little dated so they may be a little
different now.

Moli Energy (NEC) IMP-18650 3.8v, 1.2Ah, 5Wh,  268 Wh/l, 109 Wh/Kg

Panasonic P-110AAS                 1.2v, 1.1Ah, 1.32Wh, 133 Wh/l, 45.5 Wh/Kg

Roughly 2 times the energy per unit volume for the lithium ion vs NiCd
Roughly 2.5 times the energy per unit weight for the lithium ion vs NiCd

I believe the lithium ion numbers get a little better for larger cells.

The PIC14000 is designed for this kind of application. For the volume of
product I build the higher development costs of a non flash processor
would not make it attractive.

I have built a battery charge based on a PIC16C84 and a LTC1325 that
was originally designed to charge lithium ion batteries. However, the lithium
 ion cells
were not available for the volume I was interested in. I ended up using NiCd.

I have found that lithium ion batteries are very hard to find for small projects
 and
when you can get them they are significantly more expensive. I believe most of
the lithium ion production is being absorbed by the cell phone and laptop
 market.


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| Dr. Kevin Dale Kirmse
| PhD Electrical Engineer
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| King of Prussia, PA 19406
| kirmse@netaxs.com
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