I'm having one of those moments where I cant work out anything.
12 volt led driver feeding garden lighting, run of 40 metres is proposed. 80 watts total load, led driver is rated at 150 watts. Is it the 12 volt ampage for the calculation, or the mains? I am presuming the 12 volts for the calculation, which gives 7 amps current draw, which , on 1.5mm cable, gives a near 60% volt drop.
Does that look about right?
If so, it is going to need either mains voltage outside lights, or local transformers.