Thanks for the in depth responses all.
As far as turning down the power, we usually stay on channel 6 which by default reduces the radio output to 5 watts, so nothing I can do there unfortunately. I haven't noticed any difference based on proximity to convoy but I will look out for that now.
I'm not sure I've ever been able to to talk to anyone near a mile away before, but we do live in NY with lots of hills and obstructions, and I'm the only one in the group with a high power radio.
Re changing from narrow band to wide band, I can give this a try, I do have the programming cable if I can find it. Truthfully my radio knowledge is not in depth enough to know how that effects anything but I'll give it a try.
Regarding the battery charger, its a redarc BCDC 1250D, does both float and high amp charging, and the aux battery is a new optima yellow top, and majority of the time the only thing running on it is this radio, so I'm hoping that will rule out the power draw theory.
Re changing where I hold the mic, a very quick test should yield some results so I'll try this as well!