sedan struggling to start

[YarisSedan]

yeah corossion on the battery will kill the battery faster draining voltage and amps overnight creating a weak start. Espcially if it only happens on a cold morning. Altenator is charging fine because you would have a battery light on.

Another possibility to hard start is carbon buildup inside the engine and manifold. Carbon absorbs the fuel and also gums up everything making it much harder to start. Especially if you are using low quality discount gas without any detergents to keep the engine clean then you probally do have a bit of buildup which is why it takes little longer to start the car.

Maybe time for a fuel system service.