MPPT Solar Charge Controllers
VarioString series VS-70

The VarioString family consists of 2 models of MPPT solar charge controllers with 70A or 120A battery charge current for 48V batteries.

With the MPPT solar charge controllers of the VarioString series, the solar installations will see their costs optimised while at the same time guaranteeing a better than average solar production and keeping the battery in the best condition possible.

An exceptional device
The installation costs of the solar generator are significantly reduced thanks to the elevated PV input voltage range. It is this unique characteristic that permitted the VarioString to win the internationally renowned "Solar Award" in the category "BOS", Balance Of System.

Efficient
Despite the conversion from a high voltage solar (600-900V) to 48V battery voltage, and galvanic isolation between the PV and battery, the VarioString achieves an efficiency >98%: the highest efficiency in the world in its category.

Flexible
The VarioString is designed to be used in all types of solar systems, and the combination of the VarioString + Xtender results in a highly efficient system. The communication between the devices permits the synchronisation of the battery charge cycle regardless of the technology (lead acid, lithium, nickel, etc...). Unlike other all-in-one hybrid solutions, the VarioTrack + Xtender allows to independently select the appropriate capacity of solar PV and inverter/charger, resulting in a more finely tuned system design.

Features and performances

• Reduces Balance of System costs (eliminates expensive wiring for parallel strings, saving wires, connectors, junction boxes, fuses, space, time, etc.)  
•  Safe, simple and trouble free connection with SUNCLIX™ (Phoenix Contact “tool free”) PV connector
•  Safety, guaranteed, thanks to the reinforced isolation between the PV generator and battery and between the two PV inputs of the VS-120. This allows for independent earthing of the battery and/or solar modules*.
•  World champion for efficiency in isolated converter with >98 % conversion efficiency
•  7kW per unit and up to 15 units in parallel: 105kW
•  4 step charger fully programmable for longer battery life
•  9 LEDs to monitor status and current
• Full display, configuration and data acquisition with RCC-02/03 and/or via the internet with the Xcom LAN/Xcom-GSM or via SMS with Xcom-SMS

Many manufacturers recommend that one of the poles of the solar generator be earthed to avoid PID (Potential Induced Degradation). It has been shown that this degradation can rapidly reach up to 60% of the initial power.

More information:

  Studer VarioString VS-70 Data sheet
  Studer VarioString VS-70 Operating manual
  Studer VarioString VS-70 Catalogue
  Studer VarioString VS-70 Warranty