An integrated coolant bottle assembly includes a reservoir configured for use in a thermal system. Examples of such thermal systems include a cooling/heating system of a battery powered electric vehicle, electric power generators (e.g., motor-based systems), other physical plant installations, etc. Such a reservoir includes a first section and a second section. The second section is joined to the first section at a reservoir interface thereby forming the reservoir that is configured for storage and/or flow of a liquid medium. The first section may include an integrated channel that provides a pathway for the flow of the liquid medium. The reservoir may also include a component interface configured to facilitate connection of a component thereto (e.g., a pump, a battery pump, a powertrain pump, a chiller, a heater, a filter, an aerator, a valve, a connector, a fan, or a radiator).