I've read some old (2017) posts related to charging a FLY6 with a battery bank or similar device to extent battery life on long rides.  Using the latest firmware (at that time), the idea seemed to work as described by others as long as you turn on the FLY6 before plugging it into the charging device.  I would like to try this with my FLY12 on 100 mile rides that still take me greater than 6 hours to complete.  I like to use a blinking light setting during the daytime for safety but the light only lasts around 5 hours from a full charge (actually pretty good).

Even if this may work, I just wanted to discuss this idea with others that may want to try it.  My concern is that during long rides, it may be more likely that you will encounter rain.  With that being said, you would trying to keep your unit running longer with the back rubber charging port open while being plugged into your charger.  Potentially, this could ruin the unit if water gets into the connection.  For this reason, I do not think it is worth trying and will keep looking for an alternate light for longer rides.