Battery for Archos AV320, AV340, AV380, Jukebox Mulitimedia 20, FM Recorder 20, FM Recorder 20 V2, Jukebox Multimedia 10

This battery doesn't hold a charge very well and it takes like five days for it to fully charge my device. I have an old archos jukebox multimedia 20 that I was hoping to get some music off of. The battery is brand new but is probably as old as my device and so the thing probably lost is power over time whilst sitting in its packaging.