Rockbox.org home
release
dev builds
extras
themes manual
wiki
device status forums
mailing lists
IRC bugs
patches
dev guide



Rockbox mail archive

Subject: Re: BATTERY-FAQ and the FM
From: Neon John (johngd_at_bellsouth.net)
Date: 2003-06-05


On Wed, 4 Jun 2003 16:15:07 -0700, Vincent Kujala <kujala_at_geog.ubc.ca> wrote:

>Yeah, I can remove my JBR FM20 battery quite easily. I'm
>sure it won't be long before some enterprising individual
>offers replacement batteries if Archos won't.
>
>My battery is labeled 1100mAh 4.2V - it has a thin foil
>wrap holding two individual cells together (in parallel).
>I customized my copy of CVS code to default 1100mAh (can't
>down scroll from CVS-030530 default 1500mAh).

Hmmm, I wonder if this is where the battery life discrepancy is coming from.
Mine is labeled 2200 mah (I mistakenly said 2500 earlier), 4.2 volt. Here is
a quickie snapshot of the unit:

http://bellsouthpwp.net/j/o/johngd/files/misc/FM_battery.jpg

Does this one look like yours? I've had my unit about a month. It has the
blue bumpers.

Mine is two 1100 mah batteries taped or heat shrunk together. I've seen this
style battery in battery catalogs. I don't see any reason why they'd need to
be taped together. Just drop two down in the unit and go.

My unit gets only a bit warm during charging. When the charge is complete the
unit returns to almost room temperature. I have the display set to stay on
when plugged into shore power so I assume that's the source of the tiny bit of
heat. The Li batteries should NOT remain hot after charging is complete.

One other thing regarding power. Last night I changed my battery/carry bag
around from the Rio Volt to suit this unit. This is a small camera bag in
which I carry all my accessories, including a small set of unamplified
speakers. It also contains a pair of 4 ah, 6 volt gell cells (available from
Lowe's, Home depot, etc for emergency EXIT lights) connected to a power cord.
I formerly had them in series with a 9 volt regulator for the Volt but now I
have them in parallel. Lowe's has an 8 ah 6 volt battery which would be more
convenient for this application.

With the Volt I simply played the unit whenever it was convenient to have it
in the bag, such as a weekend camping trip. I'm still experimenting with the
FM recorder to determine what the best use of the battery is. I THINK it will
be to allow it to charge the internal battery, then disconnect.

This is a VERY nice setup, allowing me to listen continuously for a whole
weekend without external power (at least I could with the Volt - we'll see
with the FM), handy for long camping trips.

John

>
>I typically get 6-8 hours playback time, slightly less than
>4 hours recording time. If I leave it plugged in overnight
>it tends to heat up near the power connection - I've installed
>an AC timer to switch on/off at 1 hour on, 1 hour off for long
>overnight recording sessions. I'm concerned that overcharging
>might fatique some of the power regulation circuitry if not the
>battery (pure speculation here). I'm trusting the Lithium Ion
>battery will stand up to this charge/discharge cycle - otherwise
>I'll be shopping around for a new battery before too long.
>
>As for replacing the hard drive, muchas gracious to the list
>for earlier discussions ("quiet drives"). I know I have to
>unsolder the tin cover plate to extract the drive - warrantee
>violation I'm sure, whatever. If you can't handle a soldering
>iron and/or you're squimish about warrantees don't bother.
>I nearly blew something up when I forgot to remove the battery
>and my iron slipped onto a capacitor (spark!) - I'll know
>better next time.
>
>I do my bit to advertise RockBox, all my friends know how
>cool I think this project is. They might even think about
>buying an Archos if/when they buy a recorder/player.

---
John De Armond
johngdDONTYOUDARE_at_bellsouth.net
http://bellsouthpwp.net/j/o/johngd/
Cleveland, Occupied TN



Page was last modified "Jan 10 2012" The Rockbox Crew
aaa