Hi all: OK I did my home work.
I changed all the set up to the front, close to the car battery. I attached all with the Renogy 'official' cables from a 2000w inverter (I think they are 4 awg -maybe 2?- but enough for 50 amps). I tried the 80 amp breaker (and later a new one I had of 60 amps, just in case). In all cases after 1.45-2 minutes the breaker 'jumps'. My ampere only works for AC (yesterday was giving me 0.33 A and I new something was wrong so today with the manual I found out that the option for DC only measures volts :-( ) I checked volts of the car battery and were in 14.17 (at the car battery and at the charger). Leisure battery13.18V at the battery and same at the charger. All the time the battery was getting a flat 50.3 -51 amps (as per the BMS).
Not sure if I need to buy an ampere, but what can be the reason for the charger to be sucking 80 amps and 'only' sending 51 amps to the leisure battery? Malfunction? What is your recommendation? Buy an ampere, or just send back to Renogy? I bought it in March... it will not be easy.
I am not happy with them, I expend 1.000 eur and the 2 expensive items were bad, this charger and the inverter.
Thanks a lot guys.