(sigh)
So the magnetic charger was unreliable as it would occasionally be pulled down by gravity and I would wake to an uncharged phone, not such a big deal.
Then I had it in the shop where I was do ing some light grinding of some stainless steel, apparently the dust was magnetically attracted to the charger and when I grabbed it form the bench I noticed it was partly melted.
That and having to keep track of the tiny charge adapter when I was using regular microUSB chargers and cables(no data on the mag-cable).
I guess I am back to regular microUSB and being super careful with my N900.
I am probably down to my last of 5-6 N900s between a few crap fake "new' Chinese refurbs and a few real N900s which either broke the microUSB or failed SIM, which again happened last week to my phone. I took my Wife's N900 and she is leaving the Maemoverse.
I think that this thread being about Qi I will make what is probably a final comment on the topic. Qi is a neat idea, but it really needs to be installed in a phone specific fitted tray or drop in stand, these universal pads are universal, but there is no way to know if you are getting optimal or anything above minimal charge.