Dash cam install causing battery to go flat?

[will.g]

I was half way through hardwiring dash cam yesterday when it started to rain and was getting dark so decided to stop where i was, close everything up and come back to it tomorrow. last night drove the car to the shop and back with no issues. came back to the car today and the battery was dead.

i have not yet plugged in the fuse to the cars fuse board, but have earthed the other cable. Why did the battery run flat, is the earthed cable causing an issue?

worried i may have knocked a connection etc in the fuse box. any advice please?

thanks in advance for your help

Make - Peugeot
Model - 308
Engine size/Type - 1.3
Year - 2018
Mileage - 40 000

 

[flameport]

If the camera isn't connected, it has nothing do do with anything.

More likely is that a door or the boot was left ajar, causing an interior light to remain on which is what drained the battery.
Or an interior light was switched to be on permanently, or exterior lights were left on.
Not impossible that the battery was already ruined, and this just happened to be the day it finally gave up.