Now I had a similar case that the browser froze when showing 24h of data. Tuned out that 80k points are a bit much. I changed the code so that it starts binning when showing 8h or more. This is not a perfect solution. The code should check at which interval data is written, then 
automatically start binning when approaching 4000 points or more. That would however require more complicated code, so I leave it as it is right now. Feedback welcome.

Stefan