5 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
Turkish owner: new Redmi 13C charges slowly and overheats
A Turkish owner on iFixit reports a new, out-of-the-box Redmi 13C that dropped from a 30-minute charge to a 2-hour charge and overheats severely within a few weeks of purchase.
What to check. A Turkish-market buyer should watch for slow charging and overheating early in the device's life; this owner reports paying repair shops repeatedly without a fix, so a warranty claim early on matters.
Redmi 13C shuts down when unplugged during charging (battery degraded)
Official Xiaomi support FAQ for the Redmi 13C lists a degraded/low battery as a cause of the device shutting down the moment it is unplugged from charging.
What to check. If the phone dies right after being unplugged, the battery is the first suspect; Xiaomi recommends an authorized service center check/replacement rather than a DIY fix.
Redmi 13C stuck in bootloop after flashing an official ROM
An XDA owner thread documents the Redmi 13C (gale) entering a persistent bootloop after a failed official-ROM flash, with the device then locked and hard to recover.
What to check. Flashing or updating this model carries a real risk of a bootloop if the bootloader state is wrong; a buyer should not attempt unofficial flashing without confirming the device is unlocked.
Official Xiaomi support acknowledges the Redmi 13C camera app freezing, with a note that if troubleshooting fails there could be a hardware issue.
What to check. Camera freezes are common enough that Xiaomi ships a dedicated FAQ; most are fixed by cache clears and updates, but persistent freezes point to hardware and a service visit.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko Smartphones catalog, version 0.1.1, under the CC-BY-SA-4.0 license.