Hello,
for my house I will install PV during next spring and I want to use Victron devices with Pylontech 48 V LiFePO4 batteries (4x US2000C or 3x US3000C). I will have 2 strings - one string to south-east (10 panels 330 Wp, 5S2P - 2 parallel sections with 5 panels in series, 3300 Wp in total) and one to south-west (12 panels 330 Wp, 4S3P, 3960 Wp in total).
I was planning to use MPPT SmartSolar 250/60 for S-E string and 250/70 for S-W string. For example type 250/70 is (according to datasheet) suitable for nominal power 4000 W, but its apparently valid for charge "absorption" voltage approx. 57 V. For this voltage max. output current of 70 A should be sufficient without any significant PV power limitation according to my calculations including losses (<70 A for panel temperature >10°C). If I will use Pylontech batteries I must set charge "absorption" voltage only to 52 V (due to problems with overvoltage warnings), so theoretical PV max. power with 250/70 will be only 3640 W (practically <3600 W due to MPPT efficiency.
So I must use more expensive 250/85 (which is only in VE.Can modification) instead of 250/70 only due to Pylontech batteries, if I am right? Similar situation is also for S-E string with 250/60...
Many thanks for you answers!
