I was plagued with issues and that cleared up when I went to better batteries, got away from the 1980's tech level of power. If you are not having issues, that is great, but the transmitter is not happy with low voltage and a NiMH is 1.2 volts while the Alkaline AA they are designed for is 1.5 and the NiZN is 1.6 volts.

I invested less than $20 in a couple of chargers and about $2 each the AA sized NiZN batteries and it has paid off better than most things I have bought into.