The Rat Upgrade: Basic Energy Transfer allows a rat with this upgrade to transfer a max of 100 kRF at a time. RF and RE can be transferred. Like all Rat Upgrades, it can be applied to a rat by placing it in the upgrade slot in the Rat Menu.
When collecting energy, the rat will only attempt to extract energy from the bottom face of the source block[1].
Transfer energy using a cheese staff to control where the rat takes the energy from and deposit the energy into.
Crafting[]

Crafting recipe for Rat Upgrade: Basic Energy Transfer