I have a multiplus 1, 48/5000. I have had this charging my lithium battery bank for several years and it has been super reliable. In the summer I charge my battery from my solar and in winter I charge the battery from night rate electricity. I have recently expanded my battery to 50kwh and in the 7 hours of night electricity the single inverter does not have time to charge the battery, so i decided to get 2 48/5000 multiplus II and connect in parallel. Using the exact same cable that connects the original multi and the same colour control I connected the 2 multi's and set them up a parallel. Every time I turn these on after about 30 seconds my RCD trips. Anyone any ideas. I am confident the parallel setup is correct as I work with these inverters every day, but could do with some help to fix this issue.
