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There are benefits from using higher voltage panels that can be realized when a system is designed for an MPPT controller. An MPPT controller can also be the centerpiece of a DIY converter.
Input voltage is a balancing act between efficiency / heat reduction (requires lower input voltage), the ability to overcome self-consumption losses under all conditions (requires higher input voltage), wire size and length (higher input voltage), and shading mitigation (higher input voltage).
MPPT manufacturers always specify a maximum voltage coming into the controller; some also specify a minimum or optimium voltage.
Victron: Vpanel >= Vbatt + 5v to start MPPT, Vbatt + 1v thereafter.1)
Genasun (nominal 12 systems): 15-18v for constant power supplies2)
, ⇐ 27v for PV.3)
SNA (grid tied): Vpanel = desired output * 1.41424)
generic rule of thumb: Vpanel >= maxiumum Vbatt + 30%
generic rule of thumb: Vpanel ⇐ maximum Vbat * 2.5)6)