This has already been discussed at length earlier this year:
Lithium batteries and Delta's abandonment of common sense
Delta’s policy is clear and consistent that these batteries need to be removed every time. Some GA’s may not be familiar with all the brands of luggage that may contain a battery, but that doesn’t mean the policy isn’t there even if you aren’t called out on it every time.
Reproducing my posts from that thread here for completeness:
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This is absolutely Delta's policy. From delta.com:
https://news.delta.com/delta-puts-li...afety-concerns
Customers checking a smart bag with a removable lithium ion battery must remove it and take it with them into the cabin. Customers carrying-on a smart bag containing a removable lithium ion battery must remove it from the designed enclosure prior to boarding the aircraft. This is consistent with Delta's policy today requiring customers to place spare lithium-ion batteries in their carry-on luggage.
As an electrical engineer who works with Lithium Ion batteries regularly, these are scary, scary things with a ton of energy potential. The reason you have to remove it is so the battery module can be placed in one of the lithium ion fire containment bags that are now carried onboard in case of a fire. If the battery is docked in a suitcase, you're not going to be able to safely unlatch and remove it if it's on fire, and you're not going to be able to get it into the containment bag because the suitcase will be too big. It's not an unreasonable request - it's a legitimate safety concern.
I strongly recommend finding another brand of luggage - not just because of this hassle, but also because Away is overpriced for the quality you receive. Lots of other great options out there! If you otherwise like the suitcase, just leave the battery pack at home and carry a higher quality one (I recommend Anker).
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(Here's IATA's assessment of the risk of smart bags: )
Cabin firefighting proceduresFirefighting procedures require that any lithium battery showing signs of overheating should be cooled as quickly as possible using water or non-flammable liquid.The majority of PEDs powered by lithium batteries are held and/or used during flight. Passengers and cabin crew are therefore more able to identify an overheating device and take appropriate action to cool it before the point of ignition. In the case of batteries installed within carry-on bags, these are more difficult to identify at an early stage, due to their stowage in the cabin. This should be considered in the safety risk assessment.To effectively cool an overheating lithium battery either before or after ignition, the battery should be fully immersed in water or non-flammable liquid where possible. Where a battery is not able to be removed quickly or safely, the device in which it is contained should be immersed in water. Where the overheated device is the size of a carry-on bag, it is unable to be fully immersed in water or placed in a fire containment device. This is a considerable hazard and should be carefully considered by the operator before determining a policy on acceptance for carriage
https://www.iata.org/whatwedo/safety...lectronics.pdf