Is there an optimum voltage into MPPT SCC in relationship to battery charging voltage?

[Mattb4]

Understood that higher voltage reduces amperage at the same watts. 5amps at 20v=100 watts ~ 1amp at 100v=100 watts .Also understood that higher voltage suffers less loss for a given size of conductor which allows for longer runs. Thus for transmission the higher the voltage better.

However when the SCC must convert this voltage to a proper voltage for battery charging is it better to be closer to battery voltage range or does it matter at all?

Thanks for your input.

 

[sunshine_eggo]

It depends on exactly what you describe and your system needs.

MPPT conversion efficiency is max at around 150% system voltage. It's around 2% lower at 2X that.

However, those losses are often offset by the reducing in wiring losses.

For short PV to MPPT runs, not a lot of benefit to high PV voltage. For long runs, high PV voltage may significantly reduce wiring losses.

 

[Solar Guppy]

Higher switching voltages does have losses in the converter, but typically its current where the most are generated.
I^2 * R = losses ( The squared of the current times the resistance )

The most efficient solutions are where the conversion from input to output and current is minimized, for example in high voltage all-in-one, you have a high voltage array, feeding the mppt close to the internal HV bus on the AIO which then creates AC or charging the battery, It's all low current.

 

[Mattb4]

It depends on exactly what you describe and your system needs.

MPPT conversion efficiency is max at around 150% system voltage. It's around 2% lower at 2X that.

However, those losses are often offset by the reducing in wiring losses.

For short PV to MPPT runs, not a lot of benefit to high PV voltage. For long runs, high PV voltage may significantly reduce wiring losses.

Just so that I am not misunderstanding. System voltage in your explanation is battery charging voltage?

 

[sunshine_eggo]

Just so that I am not misunderstanding. System voltage in your explanation is battery charging voltage?

System voltage: 12, 24, 48V