MPP Solar LV6548 Error F57


New Member
Apr 13, 2021
I can't seem to find anything on this so if anyone has seen this before, I'd appreciate some guidance. I have a support case open with MPP Solar, fwiw.

1-LV6548, single unit, off-grid, no utility
Battery - ~15kWh LiFePO4 battery pack w/ Daly Smart BMS 150A
Solar Panels - BlueSun Solar BSM455M-72HPH, 2 strings of 5 panels with PV1 and PV2 inputs each having one string connected

Observed the LV6548 with no LED lights and the display showing only F57. When I scrolled through the display using the up/down arrow keys, the output and input voltages were zero.

At some point, the LV6548 stopped charging the battery and the BMS disconnected. I started the BMS again and the LV6548 display showed the battery information level but does not show voltage. The solar inputs PV1 and PV2 showed voltage from the array, which could be expected as it was sunny.

I disconnected the battery and PV inputs for approximately 15 minutes. I then reconnected the PV and battery and still observed the F57 and the same behavior as before.

I then disconnected PV2 from the LV6548. When I scrolled through the display, PV1 had an input voltage and wattage but I was surprised to see an input from PV2 as well. I am not certain how this can happen.

I removed the bottom display and the front cover of the LV6548. No physical damage or burned/scorched areas can be seen.

Thanks for any help.
I have the problem fixed and I am back up and running. Short answer is I replaced the MPPT and Inverter to clear the F57. Longer answer below.

My problem was a wholesale failure. The first feedback from MPP Solar Support was that I needed to replace my MPPT and control board. That is $117+shipping. Got those in and installed them. Fired up the unit and some issues were resolved like voltage measurements but the F57 was still there.

Next support note said the inverter board needing replacing. That was $215+shipping. Got it in and replaced it. Now it works like a champ again.

I'm not certain why it failed in the first place but I'll keep an eye on it.