Reading the owners manual the other day for my 2018 Karoq SEL I came across some info about the car alarm : "The alarm system has its own power source, service life of which is 5 years. In order to ensure functionality of the alarm system, we recommend that you get the alarm checked after this time by a specialist garage." Does anyone know if this power source can be changed easily and where on the car it is ? I've never heard of this before but assumed (wrongly I guess) that it was the vehicle main battery which powered the alarm. Thanks in advance.

It is technically possible to replace the alarm unit integrated battery, but it involves cutting the unit open, then unsoldering the battery from the units PCB - which may possibly be damaged if the battery electrolyte has leaked. Unless confident of skills required for this, probably much easier to simply replace complete unit.

AFAIK, the alarm unit is located beneath the wheel-arch liner in one of the front wheel arches (usually drivers side)

The alarm integral battery is a backup to prevent it being disabled by simply disconnecting the vehicle battery, but the alarm battery SOC is maintained by the vehicle battery.