I've had a quick search of these forums (and elsewhere) but can't find a definitive answer.
I've an Oregon 600. Currently I use a set of Duracell rechargeables along with a couple of bits of beer can to press the nipple down and fool the unit into thinking it's got the Garmin powerpack.
With that setup how does the Oregon handle an external power supply, i.e. a typical powerbank type battery? Does it run directly from the external supply or recharge the internal batteries and then use power from those? Does the unit handle internal rechargeables different from non-rechargeables so if I removed the bits of beer can then power would go directly to the unit?
I'm doing a long trip, circa two weeks, I have a dynamo hub and I'm intending to have two powerbanks, charge one and use the other to charge devices. There are two ways of doing this (as far as I can tell), both have pros and cons:
1. At night plug in the powerbank and let it recharge the internal batteries.
2. Run the unit directly from the powerbank not being charged. I've an "up angle" USB cable so it can be used whilst the unit is in the bike mount - hopefully not stressing the board connector.
Obviously I can try myself but typically I've only thought of this at the last minute as we are heading off tomorrow