iPod won't hold charge

@scharre this model is a bit complicated at times (seems to vary from model to model on the 4th gen). I use a firewire charger. Aftermarket around $10USD because the iPod 4th Generation still works best with it. It syncs, but does not finish it's restore process without Firewire. I have 6 of them and do use a Firewire adapter to finish the restore process. While the iPod does technically charge over FireWire or USB, the port that you're using has to be able to supply the necessary voltage. Some FireWire ports, as well as USB ports, particularly those found on laptops, don't necessarily supply a charging current, and therefore the iPod won't charge from such a port. The port needs to be powered in order for the iPod to charge from the USB port. Maybe something like an older iPad charger would supply enough "oomph" but FireWire works best for those. Give it a try and let us know. Also, check this answer iPod only shows power adapter being plugged in to wall outlet? as well as a few others.