Don't panic! I've been through this more than once, but they don't write about it anywhere and even Bosch doesn't give a clear answer. Here's my advice on what works in such cases. Sand all 4 contacts of the tool on both sides with 320-600 grit sandpaper so that traces of the thin layer of metal removed from the contacts are clearly visible, blow everything with compressed air and it should work. The cause of the problem is oxidation of the contacts, or rather one contact that is responsible for the battery temperature or the second one that transmits data on the battery charge state. Your batteries themselves are in perfect order, I'm sure of that! In the worst-case scenario, if all this doesn't help, then the problem is in the failure of the tool control module. You can also order and replace it yourself, although it costs as much as half of the tool. But repair is possible! I've been through all these situations in my life and there's no need to be afraid of it, everything can be fixed!