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Subject: Re: External battery pack options for FMR

Re: External battery pack options for FMR

From: Todd Lowe <>
Date: Wed, 13 Aug 2003 02:52:10 -0700 (PDT)

> > I will say that 2-2.5 hours sounds very poor performance however. I
> > certainly get a lot longer out of mine. How do you charge the unit? Do you
> > remove the power as soon as the charge shows 100% in Rockbox? If so, leave
> > it overnight, as Rockbox currently shows 100% long before the charger
> > stops charging because the battery is full.
> >
> I agree. I listen to 200ish VBR and 256 CBR all the time on my player,
> and I generally get 6-10 hours with 1800 MAh NiMH's. I understand the FRM
> should have similar run-times.

I ran an experiment today with interesting results -- previously, I had
always gauged battery life from use on-the-go. Today, I started with a
fully charged battery, set it on my desk, and let it play undisturbed.
It ran for 4.5 hours, and still had 3.2V on the battery. I moved it to
another room, and when I plugged it into my stero connector, it went dead.
I tried to reboot it again, twice, but it didn't seem to have enough juice
to boot. I figured the batteries finally were spent. (BTW, I have
already applied the Rockbox flash to the rom, it works great, no probs w/
quick boot).

THEN, I plugged it back into the AC charger just long enough to get it to
boot (< 1 minute) and I unplugged the AC charger cord. The unit then
continued to run for 5+ additional hours, again, undisturbed, and was only
down to 2.8V when I had to leave.

So, I'm beginning to think it might be a loose battery lead inside -- when
I handled it to move it between rooms (and when I'm on the go), it must
lose its connection and die early ??? (i.e. at between 2-3 hours).
My conclusion is that the LiIon battery is not really that bad, its simply
a construction Q/C problem.

BTW, I have seen instructions on the web for taking the FMR completely
apart, resoldering connections, etc., to fix this kind of trouble but I've
never soldered anything, and I don't want to practice on my FMR. Not to
mention never getting the battery cover to stay on properly again...

> Do you have sane setting on things that eat batteries, such as backlight
> timeout and the like?

Yeah, the backlight is only on for 3 sec, and my file directory limit is
800 files (does this make a huge diff in the memory used for the song

Anyone that is tracking battery voltage change stats, I'd be glad to pass
on data from my FMR.

Received on 2003-08-13

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