Hey everyone, I'm working on a project where I have a solar array rated at 105VOC (1050W) and I need to connect it to an MPPT charge controller with a maximum voltage limit of 60V (20A). The tricky part is that I can't rewire the solar array or swap out the MPPT for a different model. I'm looking for effective ways to reduce the voltage from the solar panels. Would using a step-down converter do the trick? I'm a bit skeptical about running a second MPPT in line to drop it to around 48V, as I'm not sure if it would function without seeing a load on the output of the main MPPT. I'm ready to invest in a solid solution, so if anyone has experience with this, I'd love to hear your thoughts! Thanks!
3 Answers
Why not just change the MPPT? It's not connected yet, right? It seems odd not to rewire it since the MPPT can handle 1200W; you might be able to make it work without any crazy hacks! But without a clear reason for the restriction, it’s tricky to suggest a good solution.
You'll want to look for a PV-grade DC-DC buck converter for this setup. Just make sure it's specifically designed for handling input voltages above 105V and is suitable for outdoor conditions—many cheaper models just won't cut it for solar applications.
You could consider using a second MPPT along with a buffer battery. If you connect a 48V battery to the existing MPPT, it should work as long as the MPPT doesn’t short the panels if it shuts down. Just check the manual to be sure!
I thought connecting a 48V battery would be problematic since the MPPT might hit its power limit and stay stuck there until the battery dies from low voltage. You might need something that regulates the voltage output more effectively, maybe like a proportional voltage converter.