Can I have the ANT agent on my laptop as well as my pc so when I'm not running at home I can upload my runs? How many runs can I have on my 405 before having to upload them to Garmin Connect?
Try it and see. If it doesn't work, report back and I might be able to provide some tricks to make it work. As for the number of activities, it really depends on the size of the activity file (which is related to the duration of the activity, the number of sensors in use) and the amount of free space available. Your 405 probably has a System menu that can tell you how much free space is available. You can use this to get an idea of how many minutes of recording it can store. Or, you could just upload your activities often.