I agree, this is important indeed, but don’t think that this taking easy approach helps here (turning on Librem 5). Anyway, in his post #6 within this thread @Skalman already pointed out (somehow) that empty battery leads to the second problem: “starting the phone after the battery is dead enough for the RTC to reset”, see his post here: Why is there no Wifi? - #14 by Skalman.
This RTC reset issue is certainly possible as there even exist recent laptops (that include PCI IDs: 15bf, 15d9, 15d2 and 15eba) where they were able to boot into any OS, even show that the battery health status is almost 100% but its charging status was showing 0% even after several days of charging. Therefore looks like “it’s best not to let your battery go under 20%” while if the RTC lasting time completely runs out, the system will lose this information and the real-time clock/calendar won’t be able to recover, something that @sherab_kelsang didn’t take into account (as there exists no official warning, so let me finally relax). Actually, I have no clue what is going on, but I don’t think that we have any issue with the battery manufacturer (or USB-C port). IMHO, things here are complex and might even “involve SPI flash chip to store the firmware”.