Only thing I would suggest is try different chargers on your Ionic. Generally a "fast charge" charger may "kickstart" the Ionic charging process with higher 5V current. Interesting though - I used a QC3.0 fast charge capable charger (Blitzwolf) and it said the charger wasn't enough to charge the device (can't remember the exact screen message). A lower current charger didn't bring up the message.
So try several different chargers. Hopefully one may bring your battery back to life. On an aging battery, it may have dropped below a minimum voltage level - so needs a "kick" to bring it back.
Although, many owners are reporting that their device was reasonably charged and simply died. FW update I guess?
Between 2200-0330 my battery dropped from 14% to 4%. Given the discharge rate the previous day I expected I could wait until later in the morning to charge it. Not sure why it fairly quickly dropped to 4% without much usage overnight - as I was asleep. I put it on the charge at 0330. I simply don't trust letting it occasionally drop to 0%. It may stay there.
