Current changes at 48V

[Solarwanabe]

Currently running 1900W solar with a 24V battery bank. If I switch to 48V will the voltage upstream of the charge controller also increase? Will this drop the current flow from my panels to the charge controller? Using a combiner for the 2 strings of 3 panels.

 

[MisterSandals]

If I switch to 48V will the voltage upstream of the charge controller also increase?

The solar panels are upstream from your charge controller. The voltage of the array is determined by the individual panel voltages and how they are configured, especially if in series.

 

[MisterSandals]

Will this drop the current flow from my panels to the charge controller? Using a combiner for the 2 strings of 3 panels.

Actually, this depends a bit on whether you have an MPPT SCC or a PWM SCC. Using a combiner to connect strings in parallel, the current will double at the combiner.

 

[Solarwanabe]

3 panels in series, 2 strings.
VOC 40.1V
MPPT input typically 100-110V
So doubling the battery/CC output voltage will only result in having to go to a voltage over 48V on the panels before the CC can harvest power. The current from the panels into the CC will not change, just the output current from the CC should drop in half?

 

[MisterSandals]

MPPT input typically 100-110V

What is the max input voltage? That is the key piece of info for assembling your panels in an array.

I reread the thread and it seems you are asking if you need to up the array voltage above 48V? (i thought you were asking if the array voltage would increase if you upped the battery voltage).
You generally need to have solar input about 5V above your battery voltage. All these numbers should be specified by your SCC information and not answerable specifically but only with generalizations without knowing what your secret SCC is.

 

[Solarwanabe]

150V max on the SCC (Victron 150/85). Need to add strings if I want more power. Limited to 8 ga welding wire out of the combiner box so max current acceptable is around 40 amps. Looks like I will have to upgrade to a 250V SCC or get a all-in-one that will take the higher voltage.

 

[Bud Martin]

3 panels in series, 2 strings.
VOC 40.1V
MPPT input typically 100-110V
So doubling the battery/CC output voltage will only result in having to go to a voltage over 48V on the panels before the CC can harvest power. The current from the panels into the CC will not change, just the output current from the CC should drop in half?

Yes the battery charging current will drop to half (1900W/48V = about 40A).
I do not see why you have to change anything on the input side of the SCC, since the SCC is getting 40.1VOC x 3 (3 panels in series and the the two strings are connected in parallel, 3S2P configuration) = 120VDC (will be higher in cold weather), you will still feeding the same power into the SCC. You are feeding about 18A into the SCC right now with the existing 1900W of panels, is that right?
BTW, what is the full spec of the panels?