[bluepilot]

The current-carrying capacity of cables is mainly dependent on how much heat they can dissipate. A cable has a (small) resistance and that coupled with the current flowing through it will produce heat. A cable in free air can dissipate more heat than a cable rolled up on a cable drum. See post 18 where the cable on the drum had melted whereas the unrolled cable was OK. (A decent drum ought to have a thermal trip. That's quite a common problem). I use the rule of thumb that cables are fused at 6x cross section +1 amp. So for a 1.5mm2 cable I would use a 10A fuse/circuit breaker, for 2.5mm2, 16A and for 4mm2 25A. That's very conservative based on cables in conduits in walls. 13A for a 1.5 cable in free air should be no problem.