Using non-rechargeable cells for a PDQ's internal backup batt seems silly to me since the machine can and will sleep off that batt while you swap the main one or move it from outlet to outlet.

I just ask, what is the point if it is not rechargeable? It is only useful for super quickly swapping the batt and that is it, then you have to replace it soon after anyway. Seems better to just do it properly the first time and use it like it was supposed to be used to me.