Charging icon appears, but won't take charge, has New iFixit battery.

I had a dead iPod 4th gen 40 GB for years, so when I finally replaced the battery the other day with a new one from iFixit, I was very happy to see the device boot up and still show all the data I stored on it in 2007. It powered up and the battery icon showed minimal power (what the new battery shipped with), and I could play songs and navigate the device. I did not wipe and restore with iTunes, though I did hard reset a couple times to make sure everything was OK.

But it won't take any new charge when I plug it in either to a Macbook USB port, or an AC USB wall block. On a Macbook USB port it does nothing at all, like it's not even plugged in. On the AC charger, the "Charging" icon flashes in the upper right of the screen as expected, and when asleep the big charging icon is on the screen, but no actual power is being stored by the battery. When I unplug it, the battery reads empty, and after a night plugged into the wall, while it said charging, the battery is now completely dead.

What gives? Is the battery from iFixit a bad part? Is there something else that would keep the battery from recieving/storing power even when the iPod thinks it is actually charging?