Rockbox mail archive
Subject: Re: External battery pack options for FMR
From: Mike Holden (rockbox_at_mikeholden.uklinux.net)
Todd Lowe said:
>> No idea about the battery pack, but if it provides similar power input
>> to the wall-wart, it should be ok. I doubt it would do any harm, so
>> long as the volts and amps delivered are similar yo the power unit
>> supplied by Archos.
> The battery pack supplies 6V, which is the same as the voltage from the
> AC adapter used for normal charging. I assume since it is intended for
> digital cameras, it shouldn't have voltage fluxuations much above it's
> listed voltage.
It's not just the Volts that matter, but the Amps as well.
>> 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.
> Yes, it is poor performance. I charge the unit all night -- I have
> looked at the battery charge from the DEBUG screen, and it is the same
> as quoted by others (~4.25V when plugged into AC adapter at full charge,
> ~3.87V immediately after unplugged). I do suspect that the 180Kbps VBR
> files cause it to eat up the battery faster than the "average" user, but
> I'm not willing to downsample -- I have ~9000 high quality MP3s which I
> play on my car stereo and on my home stereo, and I don't want them to
> sound like 128Kbps crap (which sounds like "underwater" music to me on
> decent speakers).
Just to be sure it is fully charged, have a look at the Debug -> View IO
Ports screen, at the AN7 value. This should be around zero when the
charger is unplugged, and will go to a higher value when the charger is
plugged in. If the charger is actively charging the battery, the value
will be quite high, slowly dropping to a value of around 0C0 or less as
the battery gains charge. If the value is higher than 0C0, then the
battery is not fully charged yet.
Rockbox page: http://www.mikeholden.org/~rockbox
Page was last modified "Jan 10 2012" The Rockbox Crew