jameso wrote:The B+M USB Werk AC to USB converter has a small battery built in so it will keep a garmin off that annoying 'power lost' message during brief stops or slow climbs. ~£50. Mine's been great. I could use a cache cell with it also but haven't needed to so far.
pistonbroke wrote:I like to think of the setup as a flow of water. To keep most Garmins sweet, you need an uniterrupted flow of power, direct power from a dynamo will only work whilst you are moving, in most cases over about 8mph. A power bank is a reservoir that the dynamo keeps topped up, allowing juice to flow constantly to the gps. The tricky bit is finding a power bank that allows pass through charging and doesnt stop sending out power when the dynamo is putting power in. Ive found 2 that work, 1 is called a juice cube and only costs a fiver from Maplin, the problem is it seems to have been discontinued. The second is a Portapow 10200mAh capacity which should last forever. These are available direct from them or via Amazon for £15-20.
Hope this helps.
So you ride with your garmin diectly powered ?