To everyone who is reporting Cozmo dying suddenly and without warning, the issue most likely is due to a failed battery. Cozmo’s original battery is tiny and has a very small capacity (300 mah) That means that even in the best of days, Cozmo would only be working for maybe 10-12 minutes max before needing to be recharged. If I recall correctly, Cozmo would indicate when he is running out of battery by blinking the backpack lights red, but if the battery is in such bad state that it cannot hold a charge, then Cozmo will think it has a full charge and then drop to zero suddenly without having the chance to warn you about it. I have the exact same issue and I plan to replace the battery. I will try to document the before and after results, to try and help anyone who is facing the same problem.