I'm presuming this is normal, but out of curioisity would like to affirm as normal. I inadvertently mixed two batteries, TB-50's e.g. a C and an A, label, and the Inspire 2 would not go thru the 'start-up' routine; that is, nothing happened. I lamented, 'what now'. I tried two batteries with same label e.g. B and B, and started ok. Am I to preusme that somehow the Inspire 2 has determined the 'batteries were not the paired' ones? This was repeated on different batteries and I was able to duplicate the scenario. I.e. Paired batteres worked fine, 'mis-paired' batteries would not work. That is, the Inspire 2 would not go thru start-up routine.