These are boxed itel solar power generators.
Model: The boxes are likely for the itel IESS-05K10N.
Capacity: Each unit includes a 1kWh (1000Wh) LiFePO4 battery and a 500W inverter.
Features: They support dual charging from solar panels and the grid, fully charging in approximately 2 hours.
Purpose: These compact systems are designed to provide backup power for homes or shops to run appliances under 500W.