Intelligent Solar Interface Unit (ISIU)

ISIU is independent charge controller that has the capability to interface with any existing inverter of any make to convert it into a solar inverter. It controls and limits the solar charging current according to the specifications provided along with the mains current given by the inverter. It also has the feature to disconnect the mains(only if PV is available) when battery is charged up to the boost voltage (automatically obtained and selected by ISIU during the first time charging by inverter through mains) , during this time the load is driven by the battery(s) and then reconnect the mains when battery voltage reaches <11.8V.

The current delivered by ISIU is the additive current to battery given along with the normal charging current given by the inverter to charge the battery. So in all, the battery will now be charging with increased current from nominal current earlier to inverter current + Solar current and hence battery will charge faster and after maintaining the battery to its float voltage level ISIU will cut the mains and drive the load with the solar current and battery (if required) and hence saving the electrical energy and utilizing maximum amount of renewable energy source.

Salient Features*

  • ISIU saves electrical energy by charging the battery as well as supporting the load using the solar energy. Maximum Solar Power Utilization during charging and backup mode.
  • Automatic 12V/24V Battery Sensing Capability.
  • LED indications for better system information
  • Automatic boost voltage capture: In this feature the ISIU automatically takes the boost voltage for the first time it is connected to the inverter it notices the voltage till which the inverter charges the battery and then takes that voltage as the boost voltage for its operation.
  • Compatible with any Home Inverter/UPS (12V/24V).
  • Controller based design with absolute and stable operation for managing the solar power and mains with respect to battery voltage.
  • Three Stage solar charging (TSSC) suitable for all types of battery charging.
  • Combined mains and solar intelligent constant current charging with solar power priority and load sharing capability.
  • User friendly operation and selector switch control with LED indication on front panel. Selector switch is for selecting the charging mode.
  • Deep discharge battery charging from solar.


ON ON Charging Mains + Solar Mains
ON Cut By ISIU Charged Solar Solar + Battery
ON Reconnected By ISIU B.V < 11.8V (Charging Resumed) Mains + Solar Mains
ON Grid Off Charging Solar Solar + Battery