Hi guys, Just wondering if VCDS can be used to check vehicle battery and alternator ?

You can use vcds to monitor voltage with ignition on and with the engine running

 

With engine running will give you the ouput produced by the alternator

 

with ignition on will show you the battery voltage. This test is not showing what the battery condition is, as it is not tested under load.

Thanks Eddie 

Assuming similarity to Fabia electrics, VCDS Module 09 (Cent. Elect.) should have Terminal 30 (battery) voltage in its most accurate version. If you look at Module 09 measuring block Group 2, first column, that's your battery voltage; which - all being well with the heavy-gauge wiring - is virtually the same as the alternator output voltage when the engine is running. There are dedicated sense wires going from battery to this module to give it the best possible knowledge of what the voltage is at the battery terminals.