We have had these since they came out. Very poor battery life. Even firmware update did not fix. Expect to replace cr2025 battery every month. Taking it out for a while and putting it back in will help but not cure the problem.
If it shows low battery on the Zip, try this. Then in a day or so! the low battery sign usually disappears from the Zip.
Otherwise, this is a great product. Perhaps they have fixed this problem, but nothing we have tried has helped. We buy CR2025 batteries in bulk from MEC. ( name brand)