When clearing security on a Domestic leg at BLR, the CISF confiscated a couple of spare AAA batteries I had in my hand luggage for my headphones. They are ok with batteries installed in a device but not spares.

FWIW, none of the stores in the secure area of BLR or Delhi terminals carry AAA batteries.

I didn't find a prior post on this topic. Figured having this here would help someone in the future.