Wow! Marian just told me that you have the same problem that I have. Imagine tracking an Eagle in clear sight coming over from far away, in a clear sky, and as he gets close you know that it's going to be an exceptional photo. Then, as you click, the camera shuts down with that dreaded #replace the battery" signal. Then you fumble in your bag for a charged battery, keeping your eyes on the bird, and by the time that you load the new battery, the bird is gone 🥴

So, I know exactly how you felt, and I am also addicted to Canon 😉 !LOLZ