Battery saver feature - why must the BATT+ wire be connected to hazard lights?

[Stratus]

"Note To use battery saver feature, connect the BATT+ cable to the hazard light fuse. Functions of fuse differ by manufacturer or model. For details, refer to the vehicle owner’s manual." These are the hard wiring instructons for my Blackvue dashcam.

Can someone explain why the BATT+ cable can only be connected to the hazard light fuse to use the battery saver feature? Why not just splice into the wire before or after the fuse? There are also other fuses which remain hot after the car is switched off and for that matter lots of other hot wires available in the dash meaning I don't have to run everything through the firewall ....

Cheers

 

[Nigel]

Why not just splice into the wire before or after the fuse?

Much easier, more reliable and less risky to use a fuse tap / piggy back fuse to connect, but functionally a good splice would work the same.

Can someone explain why the BATT+ cable can only be connected to the hazard light fuse to use the battery saver feature?

I think this advice is because the hazard light fuse is expected to never turn off, there may even be a law requiring them to always be powered when parked, since there are also laws requiring you to use the hazard lights while parked if your car is stranded in a dangerous location. Other fuses may get powered down after a while, especially on cars like BMW which complain about battery power drain.

Realistically, there is no way that it can tell which fuse it is connected to, so if you are sure that you have a suitable alternative, then there is not going to be any issue in using it.