The variostring high voltage MPPT solar charge controller ensures an optimal charge of the battery maximizing the solar production. First of its kind, the variostring achieves the highest conversion efficiency in the world from high voltage solar power (900V) to 48V battery voltage, including a galvanic isolation between the PV and battery. 100% designed and manufactured in Switzerland, the variostring offers a 10-year warranty.



Safety guaranteed, thanks to the reinforced isolation between the PV generator and battery, allowing for independent earthing of the battery and/or solar modules

Safe, simple and trouble-free connection with SUNCLIX™ (Phoenix Contact “tool free”) PV connector


World champion for efficiency in isolated converter with >98 %


Reduces Balance of System costs (eliminates expensive wiring for parallel strings)

4 step charger fully programmable for longer battery life

Advanced battery accessories

bts 01 Temperature sensor

bts 01

Temperature sensor

bsp Advanced battery processor (lead-acid)


Advanced battery processor (lead-acid)

xcom CAN Communication with lithium BMS

xcom CAN

Communication with lithium BMS

Display, datalogger, monitoring and communication

rcc 02/03 Configuration, display, datalogger

rcc 02/03

Configuration, display, datalogger

xcom LAN/GSM Remote monitoring (Portal & App)

xcom LAN/GSM

Remote monitoring (Portal & App)

xcom 232i/CAN/485i Communication bridges (openstuder)

xcom 232i/CAN/485i

Communication bridges (openstuder)

Compatible accessories

vario solar charge controller


solar charge controller

xtender battery inverter


battery inverter

arm 02 External auxiliary contacts module

arm 02

External auxiliary contacts module

Technical data


variostring vs70