Checking the capacitor in the transmitter boxes (Davis Vantage Pro2)

The transmitter boxes of the Davis Vantage Pro2 derive their energy from the solar modules in the covers of the transmitter boxes. The energy is stored in a capacitor in order to supply the transmitter unit with electricity even at night and in longer periods with low solar radiation. Only when the capacitance stored in the capacitor is not sufficient, the battery switches on.

If the capacitor is broken, the battery jumps much earlier. If the capacitor is intact, the battery will last for a whole year. If the battery is exhausted much faster, however, this indicates a broken capacitor. A further note is that the data transfer works during the day and fails at night.


How to check the capacitor

Open the cover of the transmitter box. You will now see the circuit board with the battery in the upper and the sensor connection sockets in the lower part of the box. In the middle is a white plastic cover plate of approx. 6 x 9 cm, which is attached to the board with 4 cross-slotted screws. Please open the screws and remove the cover plate. Below you will find the approximately 4 cm large capacitor. If a liquid runs out of this, it is broken. Please note that the capacitor is fixed to the circuit board with a rubber-like compound. So please do not hold it for the leaking liquid.


In some cases, the capacitor can be broken even if the damage is not visible. This is however almost exclusively for very old transmitter boxes.

What can be done with a broken capacitor

  • Installation of a new capacitor by us. Send us the transmitter box, we'll replace the capacitor with a new one.
  • Installing a new board. Send us the transmitter box, we're going to build a new board.
  • Replacing the transmitter box. Optionally with or without solar cover.

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