Originally Posted by sfdf
I do not have the 536 only the 436.
What I have read between the line it has to be ON for it to charge.
Hopefully Paul on Monday or sooner can confirm this, as I have seen he can not stay away from here even on the Weekend.
I think the 536 needs to be on to charge the clock battery while the 436 needs to be off but not positive on that.
I know the 436 will not charge its operating batteries unless it is off and attached to an active powered USB port but I'm not sure if the clock battery is also charged on the 436 in the off state.
Being as it is such a small current needed to charge the clock battery, I would think the 436 should charge it when powered on in the 436 models.
Leaving either model turned on for 50 hours is how I read the manual as far as charging the clock battery goes.