Sako Sunon IV 4.2K 4kW Off-Grid Inverter

Note: 4000 W and 4200 VA on a 24 V battery bank from up to 5000 W of PV, with a 60 to 450 V MPPT window on a 500 V open-circuit ceiling. 120 A of MPPT solar charging, 100 A from the mains and 120 A combined, so solar and the grid share one charge ceiling. Surge 8400 VA. Peak efficiency 90 to 93%, well below the 97% and up that transformerless hybrids reach, which on a 4 kW load is roughly 280 to 400 W of heat. Transfer time 15 ms for computers or 20 ms for appliances, with a selectable input window of 170 to 280 V for computers and 90 to 280 V for appliances. Float charge 31.5 V and overcharge cut-off 33 V. USB, RS232, RS485 for a lithium BMS, local WiFi and a dry contact. No grid export and no net metering: the datasheet has no grid-output or feed-in section, so it runs the load from PV and battery and takes utility as a backup charging source. The sheet gives no IP rating, no certification list, no warranty term and no MPPT tracker count, so those fields are left empty rather than guessed. Rated 5% to 95% humidity and -10 to 50 °C, stored at -15 to 60 °C. 13 kg. The case is 300 mm wide, 481 mm tall and 130 mm deep; the sheet labels that row D x W x H, which does not match a wall-mounted box of this shape. Against the 6.2K: same case, same weight, same charging currents and the same MPPT window, with 2000 W more output, 1000 W more PV and a 48 V bank instead of 24 V. Price shown is the w11stop.com listing, Rs 155,250 (in stock), read 22 September 2026.