BatBox is a block that can store EU for future use. You can, for example, connect it to a regular Solar Panel and store energy during the day for using it when it's night. It has 5 input faces and 1 output face (the face with the dot). It accepts 32 EU/t before exploding (LV).
BatBox can also recharge RE-Batteries, chainsaws and any other IC² electric tool. However, it is slower than the MFSU and MFE at recharging tools, since it can only deliver up to 32EU/t.
One of the useful aspects of the BatBox is that it resets the energy loss from Insulated Copper Cables, so you can form a BatBox chain with 4 Insulated Copper Cables and 1 BatBox at the end, while having no energy loss. This can be a cheaper alternative to Glass Fibre Cable when running long networks of cabling.