Cigarette lighter?

Anything permanently connected to the car's battery could, potentially, drain the battery. These include things like the alarm system, interior, hazard and parking lights and possibly components of the clock and/or radio code system that require a permanent voltage. The lights are normally switched off and other permanently connected components draw so little current that they have no real impact in a car that is used regularly.

In most cars, including the RAV 4.3 and 4.4, the cigarette lighter / accessory sockets are wired to be live only when the ignition is on (so the engine could / should be running). This means that accessories connected via these sockets are powered only when the ignition is on and cannot drain the battery when the ignition is off.

That being the case, if you connect you dash-cam via an ignition controlled accessory socket it won't drain the cars battery. Similarly, the useful run time of the dash-cam after the ignition is turned off is limited to the capacity of the 'battery' in the dash cam. As I understand, some folk want their dash-cams monitoring what's going on while the car is parked up and unattended - which has obvious merits ...

As I understand, dash-cam manufacturers have considered this and some have included a parking / sentry mode to extend the effective life of the dash-cam internal battery by drawing a very low current.

If you hard-wire a 'dumb' dash-cam to a permanently live feed within the car, it will be able to draw charge from the battery at all times and thus be operational at all times. But you do then open yourself up to the possibility of the dash-cam flattening the car's battery if the car is left standing long enough. 'Smarter' systems should be able to recognise whether or not the ignition is 'on' and control power consumption accordingly.