I picked up an Anker charger from Father Christmas.

Seems to do the trick :)

I used my Garmin FR 610 on the Round Rotherham 50 miler on Saturday, and it last just over 8 hours. I imagine the 410 is about the same. If you want something longer, go for a Fenix or a 310XT.

Oops

Its a 410...

I have one of these devices and its great for recording details of where you have been.

It has a battery life of about 8 - 9 hours, so I lost the last couple of miles of the end of the Marsden - Edale last year... frustrating :(

I have seen the PowerMonkey, and wondered if anyone has used this with a Garmin FR 610.

I am rather keen not to fry the watch whilst charging it, and not being an electrician, I am not too sure about power outputs etc. The mains charger for the Garmin states that its output is 5v at 1.0A maximum

I also wonder if a similar emergency charger powered by AA batteries may be better for longer events, as the PowerMonkey seems to need to be recharged itself 'back at base'.

Any advice much appreciated.