The national electrical code prohibits use of bx technically named armored cable ac in wet locations.
Armoured cable into junction box.
Use metal clad mc with a metal sheath specifically listed as impervious to water or underground feeder branch circuit cable uf either by itself or in a conduit system approved for use in wet locations if you desire additional.
Long runs of armored cable can be quite heavy and cause stress on the connector between the cable and the junction box if not supported.
Inside the garage it goes into its own consumer unit and the rest is good.
The last thing you want is for the weight of the armor cable to cause the connector to fail and allow the cable to fall out of.
Use a clamp or set screw to attach the connector to the end of the armored cable.
Step 5 attach the armored cable connector.
Thread the connector at the end of the car armored cable into the empty knockout tab on the junction box.
The problem i have is the junction outside the house where the 2 5mm meets the armoured cable i can t find any glands or outdoor rated junction boxes to suit an armoured cable and 2 5mm.
Even conduit cannot offer absolute protection against a direct hit you may want to run armored cable behind moldings where it comes near nails.
You should also place a support strap within about 12 inches of the junction box.
Steel wire armoured cable construction uses installing the correct gland fitting into a metal enclosure fitting into a plastic enclosure earth connect.
Ip68 waterproof junction box huyu 2 way outdoor cable connectors with 2 cable m20 gland wire connector electrical junction box for 5 12mm diameter cable 3 pin terminal black 4 7 out of 5 stars 415 6 99 6.