I did a dumb thing recently with my PDM and put lithium batteries in it, thinking they would last longer. Yes, it does say in the owner’s manual to use alkaline batteries. However I figured since the voltage was the same that it wouldn’t matter. Wrong!!! It is my understanding of lithium batteries that they do not “fade” out in their every day useage. Once they are dead, they quit working - abruptly. This happened to me during a bolus delivery with the PDM. So don’t be foolish like I was…do what the manual tells you and use the alkaline batteries.
But the pod kept going with it’s delivery. Once the pod receives the initial signal it knows what to do and how much to give. You don’t have to stay in range or keep the PDM on. To save batteries I turn off the PDM after the biginning of the bolus and walk off. What happened when you put new batteries in? Didn’t it sync back up and showed that the bolus was delivered? They didn’t fall out of sync did they?
Robin, I did not know that the pod “keeps” on delivering insulin once it receives the signal from the PDM. I thought that because the batteries died that the signal was lost as well. And to answer your question, Yes, once I put in new batteries it did sync back up but I forgot to look to see if the bolus delivery was completed. At the time I was really annoyed with the lithium battery failure. Another thing I didn’t know is: you can turn off the PDM and walk away after the beginning of the bolus. No wonder I go through batteries so quickly. I thought my CDE said to stay within range during a bolus delivery…but who knows? I was probably having a ‘Senior’ moment. Thanks for teaching an old dog some new tricks 
Mayumi
aka: Kathy