For example, if you buy a 20 tray device and you only have 500 watts of power, filling the trays at full capacity would result in the food not being dried properly. While on the other hand, if you have a 2 tray device and 1000 watts of power, it would result in over-dried food. Ideally, you should try to focus on batches of around 8-10 trays at 1000 watts.