Devices that generate electrical energy from a temperature difference are often used to provide energy autonomy. Since they normally deliver small voltages, the use of a step-up converter is required to get to the needed voltage for the electronics. Several such boosters exist on the market. In the practice, it is often difficult to provide enough energy when the temperature differences are small. It is well known that the impedance of the harvester can strongly influence the performance of the booster and therefore have an impact on the cost of the harvester. In this work, we present a booster architecture that allows a good impedance matching for existing TEG harvesters. The amount of energy harvested for a small temperature difference is high enough to allow the efficient use of small commercial TEGs. We show how this power management system can be combined with very low power electronics to power sensors and communicate using BLE or other wireless systems.