Thread: Garmin Drive 51 Bricked and Bootlooping Help Please

Trying to flash with a bad battery is like playing with fire because if the device suddenly loses power during flashing it can cause some essential region(s) of the flash memory to be badly corrupted. It's best to have at least 75% charge in the battery and with it reliably holding charge before flashing via USB.

It may be that the battery isn't completely dead but is inhibited from charging properly because of previously being left in a prolonged discharged state. Before removing and replacing it, unless you already have a new battery available, i suggest to test it by connecting it to a suitable 5V power source with min. current output of 2A and leave it to charge for several hours such as overnight.

PS: Note that a "System Software Missing" message can have two distinctly different meanings, one fairly benign and the other serious and perhaps even fatal because it involves physical damage to the flash memory where region 14 is located. The benign one means that region 14, which contains what Garmin rightly refers to as the "Main System Software", aka the main firmware, is either empty or has corrupt unreadable data. That's likely what happened in your case and re-flashing via Updater.exe has successfully restored it.