Battery not charging
First check the wattage on the adapter. If you have one that’s supplying less than is needed, the Mac runs and charges slowly or not at all.
- https://support.apple.com/en-us/HT201700
Other times, a unit needs service when it’s not functioning correctly. But let’s first establish if the battery can take any charge before you run a more full test of the charging circuitry. One SMC reset a week is plenty, so that’s off the table now - good work there.
- Shut down the OS while power remains connected
- Wait 30 minutes
- See if you get meaningful charge above 11%
If you want to save a trip to the store and can’t get remote troubleshooting service from Apple, I would also consider using different cables and power sources if you get no benefit from 30 minutes of charge while off.
You seem to have covered the other easy fixes than using known good power source and cables. My hunch is your adapter isn’t providing enough power for when the machine runs, but we will need some more data to conclude that (and that’s what Apple troubleshooting will also helo you determine).