Sizing checklist
- Find the refrigerator running watts from the nameplate, manual, or a plug-in watt meter.
- Allow surge headroom for compressor startup.
- Estimate runtime using battery Wh × 0.85 ÷ average watts.
- Add router, lights, phone charging, and CPAP loads before choosing a battery size.
- Treat solar panels as daytime recharge, not guaranteed overnight capacity.
Practical target
For a fridge plus small essentials, many buyers should start around the 2-3kWh class. For multi-day outages or multiple cold-storage appliances, compare expansion batteries and solar input carefully.