A battery swapping system includes: a transformer, a power conversion system, a bus apparatus, a control apparatus, and a plurality of battery swapping compartments, where the plurality of battery swapping compartments are connected to the power conversion system through the bus apparatus; the power conversion system is connected to an external power grid of the battery swapping system through the transformer; the control apparatus is connected to the plurality of battery swapping compartments; the plurality of battery swapping compartments are configured to store a plurality of traction batteries; and the control apparatus is configured to control a first target traction battery to transmit electric energy to the power grid, and is further configured to control a second target traction battery to acquire electric energy from the power grid.

The invention relates to an overlap circuit configured to be coupled between power source(s) and load(s) for power transfer. The herein disclosed overlap circuit (100) is configured to transfer electrical power to two loads or two power sources at the same time during an overlap power transfer time period. Furthermore, the invention also relates to a system comprising such an overlap circuit.

A gas monitor includes a housing defining a sensor assembly, a cellular capable transceiver, and a battery assembly comprising a plurality of slots configured to each receive a battery pack. The gas monitor is configured to operate normally with power provided by a single battery pack.