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Subject: Re: I've done it : FM Recorder opened :-D
From: Andrew Jamieson (ajamiesn_at_optusnet.com.au)
Date: 2003-02-10


Ive used Li-Ion batteries to power a device that drew ~2A peaks with two
cells in series. With cells in parallel I dont understand how you would
prevent them from draining each other due to slight differences in internal
impedance and voltage, without external ciruitry to prevent cross flow of
current.

Which is probably what they have, but I still think its wierd :) Better to
connect them in series and then use a step-down to reduce the high side
current draw.

A

----- Original Message -----
From: "Stuart Tedford" <stuart.tedford_at_piresearch.co.uk>
To: <rockbox_at_cool.haxx.se>
Sent: Monday, February 10, 2003 8:36 PM
Subject: RE: I've done it : FM Recorder opened :-D

> > -----Original Message-----
> > From: Andrew Jamieson
> >
> > However, it's interesting to see it uses two Li-Ion batts,
> > but it looks like
> > they are connected in parallel ..... _very_ wierd. Very wierd indeed.
> >
>
> No, its not that weird. I've got a data sheet for a MAX1684EEE DC-DC
> convertor IC (as used in PDA's etc) that states that a 1.5 Amp output
> requires the use of 2 Li-ion batteries, otherwise you only get 1 Amp. It
> must have something to do with the batteries internal resistance - if I
> remember rightly from my EE diploma some years ago :-)
>
> Stu.



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