An apparatus for charging a battery using wirelessly received power, the apparatus comprising: a wireless power receiver comprising a receiver coil, the wireless power RX configured to use the receiver coil to receive power wirelessly and to communicate wirelessly to a transmitter of the power, the wireless power RX having an output configured to output power to a bus based on the wirelessly received power; and characterized by further comprising: an open-loop DC-DC converter having an input coupled to the bus and an output coupled to a terminal configured to be coupled to the battery, the open-loop DC-DC converter being a converter whose voltage and/or current at its output is not adjusted based on feedback produced by the open-loop DC-DC converter itself; a linear regulator connected along an electrical power pathway from the output of the wireless power RX to the terminal, the electrical power pathway having a portion that passes from the input of the open-loop DC-DC converter to the output of the open-loop DC-DC converter; and a controller configured to enable the open-loop DC-DC converter to use the power output to the bus by the wireless power RX to charge the battery; the controller further configured to control the linear regulator to stabilize a current in the bus at the output of the wireless power RX to reduce interference to the wireless communication when using the receiver coil to wirelessly communicate from the wireless power RX to the transmitter of the power while the open-loop DC-DC converter is being used to charge the battery. a wireless power receiver comprising a receiver coil, the wireless power RX configured to use the receiver coil to receive power wirelessly and to communicate wirelessly to a transmitter of the power, the wireless power RX having an output configured to output power to a bus based on the wirelessly received power; and characterized by further comprising: an open-loop DC-DC converter having an input coupled to the bus and an output coupled to a terminal configured to be coupled to the battery, the open-loop DC-DC converter being a converter whose voltage and/or current at its output is not adjusted based on feedback produced by the open-loop DC-DC converter itself; a linear regulator connected along an electrical power pathway from the output of the wireless power RX to the terminal, the electrical power pathway having a portion that passes from the input of the open-loop DC-DC converter to the output of the open-loop DC-DC converter; and a controller configured to enable the open-loop DC-DC converter to use the power output to the bus by the wireless power RX to charge the battery; the controller further configured to control the linear regulator to stabilize a current in the bus at the output of the wireless power RX to reduce interference to the wireless communication when using the receiver coil to wirelessly communicate from the wireless power RX to the transmitter of the power while the open-loop DC-DC converter is being used to charge the battery. an open-loop DC-DC converter having an input coupled to the bus and an output coupled to a terminal configured to be coupled to the battery, the open-loop DC-DC converter being a converter whose voltage and/or current at its output is not adjusted based on feedback produced by the open-loop DC-DC converter itself; a linear regulator connected along an electrical power pathway from the output of the wireless power RX to the terminal, the electrical power pathway having a portion that passes from the input of the open-loop DC-DC converter to the output of the open-loop DC-DC converter; and a controller configured to enable the open-loop DC-DC converter to use the power output to the bus by the wireless power RX to charge the battery; the controller further configured to control the linear regulator to stabilize a current in the bus at the output of the wireless power RX to reduce interference to the wireless communication when using the receiver coil to wirelessly communicate from the wireless power RX to the transmitter of the power while the open-loop DC-DC converter is being used to charge the battery.