650Wh Off Grid Energy Storage System with 250W Solar Charging Input
This compact off grid energy storage system combines a 650Wh LiFePO4 battery, 300W pure sine wave inverter and 250W solar charging input. It is intended for selected essential loads at remote desks, communication points, field shelters and other small sites without dependable fixed power.
Build a Small Off-Grid Energy Budget
A small off-grid system performs best when the load list is controlled. Calculate the daily watt-hour requirement of each device rather than selecting the system only from appliance names.
The 650Wh value is nominal battery energy. The energy available to AC devices will be lower after inverter efficiency, internal consumption, temperature and reserve capacity are included.
Continuous Loads
Routers, monitoring equipment and low-power lighting should be calculated over their full required operating period.
Occasional Loads
Laptops and temporary electronics should be added only for the hours in which they are expected to operate.
Restricted Loads
Heating appliances, pumps and high-consumption equipment may need to remain outside the essential off-grid load plan.
Designing the 250W Solar Input
The PV input accepts 12–60V and up to 250W. The solar-panel voltage must remain within this range throughout expected temperature and weather conditions.
Solar capacity should be selected from the daily load energy and the effective sunlight available at the site. Panel nameplate power should not be treated as continuous charging power.
Cloud cover, shade, panel temperature, orientation and charging losses can reduce the amount of energy collected during the day.
Using AC or Generator Charging as Recovery
The system accepts a 90–280V AC input and provides 300W AC charging. A compatible utility or generator source can therefore restore battery energy when solar production is insufficient.
The source specification lists a 60Hz input and output platform. Generator frequency and connected equipment frequency requirements should be checked before system approval.
300W Output and Off-Grid Load Control
The pure sine wave inverter supplies a rated 300W output. The combined continuous load must remain within this rating, while temporary startup demand should be reviewed separately.
USB and PD 20W Type-C charging can support compatible low-voltage electronics without using an additional AC adapter. Their energy consumption should still be included in the daily energy budget.
The EPS transfer time is listed below 50ms. Equipment that cannot tolerate a brief transfer should be tested before the system is used as its primary backup source.
The solar panel is not included unless specified separately. Install the station in a dry, covered and ventilated location.
Small Off-Grid System Technical Data
| Nominal Energy Reserve | 650Wh LiFePO4 |
| Off-Grid AC Output | 300W / 220–240V / Pure Sine Wave |
| Frequency Platform | 60Hz Input / 60Hz ±0.5% Output |
| PV Charging Window | 12–60V / 250W Maximum |
| AC Recovery Charging | 90–280V / 300W |
| Low-Voltage Outputs | USB 2.0 / Type-C PD 20W |
| EPS Transfer Reference | Below 50ms |
| Physical System Data | 250 × 230 × 175mm / 8.45kg Net |
| Working Environment | -10°C to 40°C / 20–95% RH / Below 50dB |
650Wh Off-Grid System FAQ
How large should the solar panel be?
The panel must remain within 12–60V and 250W. Final sizing depends on daily energy use and local sunlight.
Can it power a small refrigerator?
Only when running power, startup demand, frequency and daily energy consumption are compatible with the system.
Can a generator recharge the system?
A compatible generator may be used when its output remains within the documented voltage and frequency requirements.
Is the solar panel supplied with the unit?
The source specification describes the storage unit. A solar panel should be treated as a separate item unless included in the quotation.
What information is needed for off-grid sizing?
Provide device wattage, operating hours, local sunlight, generator data and the required backup reserve.
Small Off-Grid Energy Assessment
