Electronic devices, including medical devices, with spare batteries removed or external (power banks) - Air France

What the official page says

External batteries (power banks) <= 160 Wh (lithium ion). In the cabin: Yes, but prohibited in the overhead storage bins. They must remain under your supervision at all times and be readily accessible. In the hold: No. Important: In the cabin, external batteries (power banks) and spare or removed batteries between 100 and 160 Wh are limited to 2 items per person in total. If the capacity of your external batteries (power banks) is between 100 and 160 Wh, transport approval is mandatory and must be systematically requested from Air France or your travel agency before your trip. Each passenger can travel with up to: 15 battery-powered devices and, 20 spare or removed batteries. Damaged, defective, or manufacturer-recalled devices and lithium batteries are not allowed on board.