I have a 48v system with 30kwh of Pylontec batteries and 2 x Multis. I’ve added a 250/100 MPPT and 6 x 450w solar panels on the east and west faces of my house.
The open voltage is about 200v and it produces a max of about 5000w during midday.
My calculations say that at 5000w at 200v in dealing with 25 amps which is a lot less than the 100amps the unit is designed to handle. But the MPPT itself if getting quite warm, say 30°c.
My question is: is this right and can I add more panels?
The 100A raltes to the output current to the battery. If you have 5000W running at full power charging a nominal 48V battery then you will have around 95A going into the batteries, so the device is close to max.
If you add more panels, at mid day the MPPT will self limit to 100A, so around 5200 to 5700W. Some people over panel by 30% so the MPPT throttles at mid day but you get more total yield over the day and in winter without the expense of a larger MPPT. This may not be easily available to you by adding more panels in series, the 250V input limit is a hard limit that must never be exceeded with cold panels at Voc, which 6 panels is probably close to. Adding a 3rd string in parallel with fewer panels in series may be a possibility. Your set up is well balanced.
Search for “Victron MPPT Calculator” to explore the options.
Thank you @pwfarnell