How to make inserters take out used fuel

[Air]

I've made a custom lab which works on "battery" type fuel. Charged batteries become used batteries in this process. The problem I'm having is that inserters don't take out used batteries. They take out science packs, as with normal labs, but they refuse to take out used batteries even when it's the only thing left in the lab. Here is the relevant part of lab setup:

Code: Select all

energy_source = {
      burnt_inventory_size = 2,
      effectivity = 1,
      fuel_category = "battery",
      fuel_inventory_size = 2,
      type = "burner"
    },

[PFQNiet]

https://mods.factorio.com/mod/BurntExtractor

[Air]

Thanks. I see this is known problem and not a misconfiguration on my part.

This is a limitation of how inserters work at the moment. They can only ever extract items from 1 inventory which means you simply can't use the burnt-result system with any entity that produces items otherwise.