Lithium batteries struggle in the cold. Learn charging limits near freezing, capacity loss, where to keep your power station and how to store it.
- Cold reduces usable capacity and power output, and charging below freezing can damage lithium cells.
- Keep the power station indoors and let a cold unit warm up to room temperature before charging.
- Check the manual for separate operating, charging and storage temperature ranges.
Winter is when many outages happen and when you most want your backup power to work. Unfortunately, lithium batteries do not like the cold. Understanding how they behave helps you avoid a dead unit on the worst night of the year.
What cold does to a battery
As temperatures drop, the chemical reactions inside a lithium battery slow down. You get less usable capacity, lower power output and sometimes a unit that shuts off early or refuses to run heavy loads. Capacity usually returns when the battery warms up again, but the loss can be significant in deep cold. How much depends on the chemistry, the battery management system and the load.
Every model has an operating temperature range in the manual. Often the range for discharging (powering things) is wider than for charging. Look up both and write them on a tag you can stick on the unit.
Charging in freezing temperatures
Charging a lithium battery below freezing (0 degrees C or 32 degrees F) can cause lasting damage, such as lithium plating inside the cells. Because of this, many power stations block charging when the battery is too cold, or reduce the charge rate. Some have built-in heaters. Others simply refuse and show an error.
- Never try to bypass the temperature protection.
- If the unit has been in a cold garage or car, bring it indoors and let it warm up to room temperature before charging. This can take several hours.
- Do not warm it with a heater, hair dryer, flame or on a radiator. Slow, even warming at room temperature is safest.
- Charging solar panels in winter is possible, but the station may still limit the charge if it is cold. Keep the unit indoors and run a cable out to the panels. See how to charge a power station with solar panels.
Keep it inside
In an outage, the best place for a power station is inside the living space where you are keeping warm, not in an unheated garage, shed or vehicle. Put it on a shelf or table, away from water, with vents clear. Running cords outdoors for panels or a generator is fine, but the unit itself should stay in the warm.
- Do not leave the unit in direct sun behind a window and then out in the cold overnight. Big swings are hard on batteries.
- Keep it away from the stove, space heaters and open flames.
- If you are in a cold room with no heat, keeping the unit close to you, such as in an insulated box with a lid vented per the manual, can help it hold its temperature. Never block vents or wrap it so it overheats.
Plan for less capacity
When you size a unit for winter use, assume you will get less than the label says. Build in a margin and prioritize essentials. A fridge in a cold room runs less often, which actually helps, while heating loads are a poor fit for a battery and drain it fast. Read what to plug into a power station first for a priority list, and how to stay warm without power for heat that does not depend on the battery.
Storing it over winter
- Choose a space that stays above freezing. A closet or interior shelf works well.
- Store it partly charged rather than empty. See the manual for the suggested level.
- Check it every few months and top it up.
- If it has been stored in the cold, let it come to room temperature before powering it up or charging it.
- Keep the cables, panels and manual together in a labelled bin.
Check the manual first
Different makers give different temperature limits, and they change between models. Your manual or the maker's support site is the authority. Look for operating and charging ranges, storage ranges, and any note about cold-weather protection. If you cannot find them, contact the maker before the cold arrives.
For more winter prep, read our winter storm prep checklist and browse the heat and light hub.
Quick answers
Can I charge a power station when it is below freezing?
Many are designed to block or limit charging in freezing conditions to protect the cells. Check your manual and warm the unit to room temperature first.
Will the lost capacity come back?
Usually the capacity returns when the battery warms, though repeated misuse in extreme cold can cause lasting harm.