dev builds
themes manual
device status forums
mailing lists
IRC bugs
dev guide

Rockbox mail archive

Subject: Re: External battery pack options for FMR

Re: External battery pack options for FMR

From: Neon John <>
Date: Mon, 11 Aug 2003 23:49:30 -0400

On Mon, 11 Aug 2003 09:33:51 -0700 (PDT), Todd Lowe <> wrote:

>Hi, I spent most of yesterday reading the digest, but didn't find much
>mention of successful uses of external battery backs for longer unplugged
>operation of the FM Recorder. My battery has never lasted much longer
>than about 2-2.5 hours, so I'm frustrated on long trips bus/airline trips.
>All my MP3's are variable bitrate, averaging ~180Kbps, but I didn't think
>that should zap my batteries so quickly.

Why don't you just downsample your files on your Recorder and be done with it?
The bitrate makes a dramatic difference in run time. You won't hear the
difference on the bus/plane/whatever so you're just throwing power away. I
use CDex and LAME to do the downsampling here. It can do it in place so you
don't have to mess with your files on your PC.
>I have ordered the MAHA 1800mAh Powerpack 6V external battery pack since I
>also own an Olympus C-3000Z camera, which IS known to be compatible, but I
>was guessing it should also work for the FM Recorder.
>Does anyone have a strong feeling that this should work safely (or NOT)
>with the FMR? It's only $50
>( so I
>figure it might be the next best thing to getting a new FMR battery (I've
>already modded with a Toshiba 60GB drive (MK6021 GAS) which works great!)
>so I'm not eager to try to get the original FMR LiIon battery replaced
>under warrantee (it does work, just poorly).

It would work but it wouldn't get you much. At half the capacity of the
built-in battery, that's not much power for the money.

I simply bought an 8 amp-hour (8000 mah) 6 volt gell-cell (available at Lowe's
as replacements for the emergency EXIT lights and at Rat Shack), a $5 fanny
pack at wal-mart and an appropriate connector from Rat Shack. I now have a
nice little pack that my FMR AND the battery fit into. I've never ran the
gell cell down so I'm not sure how long it will last but suffice to say, days.
Gell cells are approved for airline use so there will be no problem there.

You can get these batteries MUCH cheaper elsewhere but if you just have to
have one NOW, Lowes, Home Depot or Rat Shack can fill the need.
>And if anyone out there has found a third-party source of the 2200 mAh
>battery, let me know! (I have inquired by email from Yosh batteries about
>buying 1 or a whole lot of them to pass them onto interested buyers on
>this list at cost).

You need to check with some of the battery resellers, such as Mr Nicad (Yost &
Company). The OEMs aren't going to touch a consumer trying to buy LiIon
batteries for liability reasons. The resellers will.

John De Armond
Cleveland, Occupied TN
Received on 2003-08-12

Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy