The safest way to store a solar generator in winter is to treat it like a battery system first and a power station second. Most portable solar generators use lithium batteries, and those batteries do not like being stored fully empty, fully charged, or in freezing conditions for long periods. If you are putting it away for the season, charge it to somewhere around 50% to 80% before storage unless the manufacturer says otherwise. That level is usually comfortable for long-term storage and helps reduce stress on the battery.
Temperature matters a lot. If the generator will be kept in an unheated garage, shed, or vehicle, check the storage temperature range in the manual. Many units can survive colder temperatures while turned off, but that is not the same as being safe to charge or discharge in freezing weather. A battery can be damaged if it is charged below freezing, even if it still powers devices for a while. If possible, store the unit indoors in a dry place where the temperature stays fairly stable, ideally above freezing and away from humidity.
It is also smart to disconnect everything before storage. Unplug solar panels, remove any AC loads, and do not leave USB cables, adapters, or small devices connected. Even tiny phantom loads can drain the battery over time. If your model has a power switch, turn it fully off. If it has an app or display that stays active, check whether the battery is slowly draining and top it up every few months.
A quick maintenance check during winter helps too. Look at the charge level every 1 to 3 months, because some units lose a little battery charge on their own. If it drops too low, recharge it back to the recommended storage level. That one habit can make a big difference in battery life. Also inspect cables and ports for moisture, corrosion, or rodent damage if the unit is stored in a garage or outbuilding.
If you plan to use the solar generator during winter, bring it inside before charging it after it has been sitting in the cold. Let it warm up to room temperature first. Charging a cold lithium battery is where many people run into trouble. The same goes for solar panels if they are icy or covered in snow; wipe them clean and avoid forcing connectors when they are cold and brittle.
In short, store it partially charged, keep it dry, avoid freezing conditions if you can, and do not charge it while it is cold. Those few steps will usually protect the battery and keep the system ready for spring.
