Yes, the PodPoint might automatically cut out with a built in overload circuit, but more likely to self-limit as you say. The existing underground armoured cable from our house to the garage is heavy duty - more than 13 amps. I would guess the safe max power the cable can take is 20 amps as per the circuit breaker. So it looks like the 3kW PodPoint will be fitted. Quick check: I = P / V = 3000 / 240 = 12.5 amp. Yep, so a 13 amp 'trickle feed' charger required.