Here's a tip: if you're thinking of getting a Nintendo Switch — skip the current model (HAC-001) and wait for the HAC-001(-01), which offers significantly improved battery life.
From Ars Technica:
Switch model HAC-001-01 will last approximately 4.5 to 9 hours on a single charge, depending on the game being played, according to Nintendo. That's a 38 to 80 percent increase from the 2.5 to 6.5 hours of the original model HAC-001. For The Legend of Zelda: Breath of the Wild, Nintendo promises an increase from approximately three hours of single-charge play on the old model to approximately 5.5 hours on the new model. For comparison, the Switch Lite will get three to seven hours on a single charge, and it can last four hours on Breath of the Wild, according to Nintendo.