I tested the former. The previous generation only came with 2GB of RAM — the pricier “Fire HD 8 Plus” had 3GB — so this is a welcome upgrade. That said, it’s not a huge boost.

That’s even better than the 10th-gen iPad, which put up 10:57 in the same test, though the smaller and cheaper Fire HD 8 (2022) went even longer at 13:41. In mixed use at full brightness ...