Hi Rob, Just wanted to tell you how much I appreciate the way you take care of your customers! I swear you have the patience of Job, man. Especially to those of us that experience "equipment failure" due to something simple....like..oh.. not fully reading the provided instructions, maybe. At any rate, I did follow your advice and using the correct protocol was able to determine that both lithium cells now function as advertised. Thanks again. The pocket rocket coupled with the coiltek external speaker system is a super upgrade. I love it and it's worth every penny I spent on it. If anyone else is thinking of augmenting their SD 2200, make sure you turn the detector on first..THEN flip the toggle switch on the voltage regulator. Don't reverse the sequence or you'll be hatin life for a while and your detecting trip will turn into a sightseeing trip! I managed to successfully trip the safety circuits on BOTH my main AND backup batteries! What a proud moment. The batteries are easily reset by placing them in the charging pod for a few minutes which in my case was located at home. ( four hours away). Everythings cool now and I can't wait to get back up to my spot tomorrow.