Solar Charge Controller DC Output Voltage

[banquo]

I currently have:
Grid tied ~6.7Kw Enphase system: 19 IQ7+/Panels@355W (47.45VOC/9.69ISC), 13KWh Encharge . Self-consumption only, no Smart Switch. All currently working fine.

Challenge:
I am looking for a backup solution in the event of failed Enphase "system" or if I need to forklift my array off-grid in an emergency.

In the event of failure/emergency:
I would like to take my (up to) 19 panels and plug them into an Ampinvt 80A MPPT Solar Charge Controller (SCC) @48v. (This was based on price/review). I would have six parallel "arrays" of 3 (series) panels to keep the series voltage just below 150V (controller max PV input) ~142.35V. This should max out at just under 10A per string or ~60A for all six strings

I have about 60 new 12V 5Ah batteries. Still spec'ing required wiring: Most likely six sets of 10' 12AWG MC4 cables to a 6-string solar MC4 prewired combiner box. Then 4AWG to my MPPT. Figuring out battery wiring solution for heat/load.

Couple of questions:
1) If I set charge controller for 48V and wire the batteries for 48V, will my load output from the SCC be 48V? I found mixed results from searching internet. I have an existing 4KW Pure Sine Wave Inverter but it takes 12V only. I do not want to use a DC-DC (48-12) converter or purchase another inverter.
2) If output is 48V based on battery voltage, maybe some recommendations for combo 80A (or larger) MPPT SCC/Inverter under $1K
3) Please provide any other input/recommendations from experience

Thank you in advance

 

[Supervstech]

I currently have:
Grid tied ~6.7Kw Enphase system: 19 IQ7+/Panels@355W (47.45VOC/9.69ISC), 13KWh Encharge . Self-consumption only, no Smart Switch. All currently working fine.

Challenge:
I am looking for a backup solution in the event of failed Enphase "system" or if I need to forklift my array off-grid in an emergency.

In the event of failure/emergency:
I would like to take my (up to) 19 panels and plug them into an Ampinvt 80A MPPT Solar Charge Controller (SCC) @48v. (This was based on price/review). I would have six parallel "arrays" of 3 (series) panels to keep the series voltage just below 150V (controller max PV input) ~142.35V. This should max out at just under 10A per string or ~60A for all six strings

I have about 60 new 12V 5Ah batteries. Still spec'ing required wiring: Most likely six sets of 10' 12AWG MC4 cables to a 6-string solar MC4 prewired combiner box. Then 4AWG to my MPPT. Figuring out battery wiring solution for heat/load.

Couple of questions:
1) If I set charge controller for 48V and wire the batteries for 48V, will my load output from the SCC be 48V? I found mixed results from searching internet. I have an existing 4KW Pure Sine Wave Inverter but it takes 12V only. I do not want to use a DC-DC (48-12) converter or purchase another inverter.
2) If output is 48V based on battery voltage, maybe some recommendations for combo 80A (or larger) MPPT SCC/Inverter under $1K
3) Please provide any other input/recommendations from experience

Thank you in advance

Most battery banks charge around 60V lifepo4 has a peak cutoff voltage of 58.4V in 16S configuration. The charge controller setting should be below that, but the output voltage may be higher depending on charging modes.

 

[MisterSandals]

3 (series) panels to keep the series voltage just below 150V (controller max PV input) ~142.35V.

If it gets a bit colder than 25C/75F your panels could exceed 50Voc each and likely damage your SCC.

If you provide the temp coefficient (~.035) listed on your panel we could determine the temp this occurs.

Its too close to be recommended for most permanent installations.

 

[banquo]

If it gets a bit colder than 25C/75F your panels could exceed 50Voc each and likely damage your SCC.

If you provide the temp coefficient (~.035) listed on your panel we could determine the temp this occurs.

Its too close to be recommended for most permanent installations.

Thank you @MisterSandals. According to the spec sheet, our JAM6(K)-72-355/PR has a VOC-TC of .3%/C. So 150V max/3 panels=50/panel max. VOC@25C=47.45 and 50-47.45=2.55V. So max volt rise/panel can be .003*2.55=17.9C drop. This would mean 25C-17.9C=7.08C or ~45F is cutoff for safe MPPT input voltage. My first thought is that we don't have weather like that here in Los Angeles. Looking back at charts over the last 12 months, there are (7:45AM) mornings where the temp is 45F while the (6.7KW) array starts producing, but only ~100-200W. Is that still a risk for over-voltage input to the MPPT?

Panel specs and Ampinvt MPPT manual attached.

Also note @[B]Supervstech[/B]: batteries are AMG. Panels have never broken 300W output according to my Enphase monitoring for the last two years.