Hi @purplequeen ,
With the engine running, use a Voltmeter to check the voltage across the vehicle’s battery terminals.
You should measure a voltage reading in the range of 13.8 -14.5V DC.
(If you haven’t got a DMM (digital multimeter) or know someone who has, see an auto electrician and get them to check it for you.)
If it is higher (or lower) than this there is a problem with the vehicle’s voltage regulator.
I don’t know your vehicle so I’m not sure if the voltage regulator is mounted in the alternator or is external to the alternator.
Be '''''safety aware''''' when you do this as the engine is running. Ensure the vehicle’s emergency brake (handbrake) is applied and that the transmission is in park (or neutral)