Howzit from muldersdrift - DIY install

The norm is to put your panels facing north, but the other way to do it is to install your strings East/West. If you have limited north facing roof I would suggest you look at the east/west option.

I have 2 strings facing north on one MPPT, and then 1 string east and 1 string west on another MPPT and to tell you the truth if I had to redo my setup I would do them all east/west. You have more power for longer duration in the day.
Here is a thread with more information about it.
Solar panel direction East/West vs North

You can over spec your system on current (I suggest not more than 20% extra), but not on voltages. Although the Victron MPPTs will protect itself for over current AND over voltage, the overvoltage is not recommended. Overvoltage will shut down the MPPT (think no solar power), while overcurrent will just limit the production but you still get power.

Something else to remember is that the current limit from your MPPT is on the battery output which is not the same as the PV current.
The PV panel will run at 84V and produce the 10.85A or 911.4W. (84V x 10.85A)
Your MPPT will charge your batteries to 54V using 16.88A (911.4W / 54V)
For 4 strings this gives you 67A output
If you use the 150/60 that output will be clamped to 60A so you loose 7A.

But then remember this is all peak theory. In practice your panels are heated during the middle of the day, or that one small cloud decide to come hover over your panels for most of the day. For this reason I would rather add more panels that will give more current sooner that gets clamped at it’s peak.

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