zaurus sl-5500
use mplayer from gui
plays mp3 files fine
currently has 4 gb CF card

AGPTEK U3 8GB USB mp3 player with
recording and FM radio
support up to 128 gb
needs 1 AAA battery (good)
supports Mp3, wma, wav
weighs 22 grams
micro sd slot for memory expansion
plugs directly into computer via USB

sandisk 8 gb clip sport mp3  $49.88
iriver mp3 player
iriver iFP-790, mp3 wma 

surfans F20 hifi mp3 player, supports up to 256 gb

MM Electronicles
portable bluetooth mp3 music player with fm
hi-fi lossless support up to 128 gb
micro sd
built-in 500 mAh li battery
can I replace the battery or not?!

ipod classic battery replacement
apple designed their new ipods to be very difficult to take apart
without destroying major components
24 steps required to replace battery, no way I'm buying it

ipod 6 is even more difficult to take apart

sony NWZ-E473 battery replacement
difficult, don't bother, don't buy it

Sony MD walkman MZ-NH700
stupid sony file format
avoid like the plague!!!

Eclipse 180G2 Mp3 player battery replacement
ifixit says DIFFICULT TO REPLACE battery
don't buy it

LG MF-FD150ES mp3 player fm radio
USB cable is LG proprietary!
LG part 6850R-UDA52 and 6850R-UDA51 are unavailable

MP3 and WMA and Music Subscription Service Support - 
The ZEN Micro lets the listener choose MP3 or WMA music, ripped from CDs or downloaded from online music sites;
Micro-sized - At only 3.3" tall, the ZEN Micro is small yet powerful;
Curved to fit - Nestles in the palm of your hand and slides smoothly into your pocket;
Mesmerizing blue glow - Luminescent blue glow comes alive with a single touch;
10 electrifying colors - A full spectrum of vibrant colors to suit every style and personality;
Up to 12-hour battery life - Enjoy your music all day long on a single charge;
Removable, rechargeable battery - Unique ability to extend playtime by another 12 hours with a spare battery;
FM radio and recorder- Listen to and record crystal-clear FM radio with 32 preset station settings;
Voice recorder - Use the built-in microphone for voice recording;
Vertical Touch Pad control - Touch-sensitive controls and intuitive vertical scrolling for easy navigation;
Access over two million downloadable songs - Choose from the widest selection of downloadable 
songs on the Internet through MSN Music and other Zen-supported music services, such as Napster, MusicMatch, 
and the Wal-Mart music download store.

Creative Nomad Jukebox Zen 
early players used usb 1.1
NOMAD Jukebox Zen players feature easily replaceable batteries

LG V20
Android Nougat 7.0
expensive but repairable
smart phone can be used as a mp3 player
The V20 has a user-replaceable battery
used ones available for about $65 CAN

FiiO M9 high resolution player
$340 on ebay