From Lights to Larger Loads: Choose Your Off-Grid Inverter
Compare the full off-grid range, understand what your appliances need and bring the inverter, panels and batteries together in one sensible package.
A television and a kettle ask very different things from a solar system. Start with the appliances you use together, then choose the inverter, battery supply and panels around that real need.
Use your appliances to find a starting size
The figures below are assumed running loads. The suggested classes start a product comparison; actual labels, starting demand and the inverter’s operating mode decide the final choice.
| Appliances used together | Running total | Product class to compare |
|---|---|---|
| Lights 60 W + TV 100 W + router 15 W + laptop 65 W | 240 W | New 1 kW or C ProX 1.5 kW for these modest loads; check planned additions. |
| The same group + fridge 150 W + fan 50 W | 440 W | A 3 kW-class option offers a useful comparison for essentials including a motor-driven fridge. |
| The 440 W group + kettle 2,000 W | 2,440 W | Compare the 3 kW class and starting headroom; consider a larger class if loads overlap. |
| The 440 W group + kettle 2,000 W + cooker 1,500 W | 3,940 W | Compare 5 kW or a larger appropriate model. The 4.2K battery-only rating leaves very little running margin here. |
More choice than 1, 3 or 5 kW
| TommaTech family | Published output sizes | Useful features to discuss |
|---|---|---|
| New | 1 / 3 / 5 kW | Straightforward options on different battery-voltage platforms. |
| C Pro | 3 / 5 kW | Pure sine-wave output, WiFi and a battery communication port. |
| C ProX | 1.5 / 4.2 / 6.2 / 8 kW | WiFi; two load outputs on the 4.2, 6.2 and 8 kW models. |
| C PlusX | 11 kW | Grid/generator inputs and expansion support for a designed installation. |
Check the evening rating before you choose
The C ProX datasheet lists 1.2 kW, 4 kW and 5 kW on battery alone for the 1.5K, 4.2K and 6.2K models respectively. Their higher named outputs apply with PV and battery together. This matters when you want the same appliances after sunset.
Build the comparison around your actual use
For the 2,440 W household example, compare a 3 kW family with a larger option if you want more simultaneous use. The 48 V-class C ProX 6.2K is one larger route to assess, with its 5 kW battery-only limit kept clear. The battery bank must supply the required power and hours; the featured 51.2 V modular batteries are not suitable for a 12 V or 24 V inverter.
Finally, select the panel array around daily energy and the inverter’s solar input limits. Motor starting power, battery communication and the exact model pairing are checked before a package is quoted.