Yep... what he said.

Instead of checking the battery directly.... plug your meter into an open channel on the Rx or CB, and read it along with the telemetry. I've found my jeti telemetry and hand held volt meter are very close. (less than 0.1v diff) mind you... I don't use any regulators or CB. Just 2 LiFe batteries, into 2 switches... and into my Rx.