January 2026, somewhere in the Scottish Highlands. It is minus eight outside. My portable power station has been in the car boot since the night before. I press the power button. Nothing. The screen flickers for half a second, then goes dark. The station shows 73% charge but refuses to start.
Not a fault. Just the cold.
That day I learnt a lesson that spec sheets do not explain clearly enough. If you want to understand the differences between battery chemistries, read my comparison of LiFePO4 vs lithium-ion first. Batteries and cold do not mix well. And if you use your station in winter -- in a campervan, camping, an unheated cabin -- you need to understand what happens to avoid unpleasant surprises.
A battery is chemistry. Lithium ions moving between an anode and a cathode through an electrolyte. Cold slows everything. The ions move more sluggishly. The electrolyte becomes more viscous. Internal resistance rises.
The concrete result: the battery stores less usable energy and delivers it more slowly.
At 0 degrees, a standard lithium-ion (NMC) battery loses roughly 10-20% of its effective capacity. At minus 10, it is 20-35%. At minus 20, some cells simply refuse to function. Not because they are empty, but because the chemistry is too slow to deliver the current demanded.
LiFePO4, the technology found in most recent portable stations, copes slightly better in discharge. It generally works down to minus 20, where NMC gives up around minus 10. But "works" does not mean "works well." At minus 10, LiFePO4 also delivers 20-30% less capacity. You think you have 1000 Wh; you actually have 700 Wh.
Discharging a battery in the cold is a performance loss. Charging it in the cold is a risk of permanent damage.
When you charge a lithium battery below 0 degrees, the lithium ions do not insert properly into the graphite anode. They deposit on the surface as metallic lithium -- a phenomenon called "lithium plating." This deposit is irreversible. It permanently reduces battery capacity and, in extreme cases, can create dendrites that cause an internal short circuit.
Put plainly: charging your station at minus 5 even once can cost it 2-5% of capacity forever. Do it regularly and you kill the battery in a winter or two.
Good manufacturers know this. Most recent stations have a BMS that blocks charging below 0 degrees. The EcoFlow DELTA 2 shows an error message. The Jackery Explorer 2000 Plus refuses to start charging. The Bluetti AC200L does the same.
But not every BMS protects against this. Entry-level or older stations may lack this safety feature. Check your model's spec sheet. If the charging temperature range starts at 0 degrees and the manufacturer confirms an automatic cut-off, you are protected. Otherwise, it is down to you.
LiFePO4 has two advantages in winter conditions.
Its crystal structure is more stable. Freeze/thaw cycles do not deform cells as badly as with NMC. After 50 cold cycles, LiFePO4 retains capacity better.
Its low-temperature discharge tolerance is superior. You can draw current at minus 20 from LiFePO4, where NMC is already in protection mode. Not at full power, but enough to run a fridge or lighting.
In March 2026, the question hardly arises. Nearly all mid-range and premium stations have switched to LiFePO4. But if you have an older NMC model, be doubly vigilant in winter.
Rule one: never leave your station in an uninsulated space in hard frost. The car boot overnight is the classic mistake. Boot temperature drops to near the outside temperature within hours. If you sleep in a van, bring the station inside the living space. Your body heat and the van insulation keep it above 5 degrees even when it is freezing outside.
Rule two: insulate the station itself. Nothing fancy. A wool blanket, a sleeping bag wrapped around it, or better still, a polystyrene box cut to size. The idea is not to heat the battery but to retain the warmth it generates naturally whilst operating. A station discharging at 200 W produces enough residual heat to stay above zero if properly insulated.
I use a neoprene sleeve I made from a cut-up yoga mat. Cost me 15 quid and has done the job for two winters.
Rule three: warm up before charging. If your station has spent the night in the cold and you want to recharge it in the morning, switch it on first and let it run a small device for 20-30 minutes. Discharging generates internal heat that raises the cell temperature. Once the BMS detects an internal temperature above 5 degrees, charging will be permitted and safe.
Some premium stations have active preheating. The EcoFlow DELTA Pro and Bluetti AC500 contain internal heating elements that warm the battery before charging begins. This consumes some energy but automates the process. If you live in a cold region and often charge by solar in winter (the panel produces early morning when it is still cold), this feature justifies the premium.
Rule four: store between 40% and 60% charge when not in use during winter. A fully charged battery suffers more in the cold than a half-charged one. To understand why, my guide on the watt-hour explains the relationship between voltage, capacity, and energy. Between 40% and 60%, cells are in their comfort zone.
Do not wrap your station in a bin bag for insulation. Plastic prevents ventilation and encourages condensation. Moisture plus electrical connectors equals corrosion. Use breathable materials.
Do not place the station directly against a heater to warm it quickly. A thermal shock (going from minus 10 to 40 degrees in minutes) causes condensation inside the station. Water forms on circuit boards, the BMS, connectors. Let the temperature rise gradually.
Do not charge by solar below 0 degrees without verifying your BMS blocks it. Solar is treacherous: the panel produces current as soon as there is light, even at minus 15. If your station accepts this current without temperature control, you damage the battery at every sunrise.
Do not store your station in an unheated garage all winter without running it. Batteries at total rest in the cold can drop below their minimum voltage through self-discharge over several months. Run your station once a month, even for 10 minutes, to keep the cells active.
In the van, my station (Jackery Explorer 2000 Plus) sleeps inside the living space, on an insulating mat between the front seats. At night, interior temperature drops to 5-8 degrees when it is minus 5 outside, thanks to van insulation and my own body heat.
In the morning, I fire up the diesel heater. Temperature reaches 15 degrees in 20 minutes. By then the station is at 10 degrees minimum -- comfortably warm enough to charge.
If I need to solar-charge, I wait until the sun has warmed the ambient air above 5 degrees. Usually between 10 and 11 am in winter. I lose an hour or two of morning solar production, but I preserve my battery.
In prolonged hard frost (below minus 10 for several days), I reduce consumption to limit cycles. Fridge goes to eco mode, lighting to minimum, diesel heater takes over for the essentials.
The EcoFlow DELTA Pro and DELTA Pro 3 feature active battery preheating. When internal temperature drops below 5 degrees during a charge attempt, heating elements warm the cells before charging starts. Takes 10-20 minutes, consumes some energy, but protects the battery automatically.
The Bluetti AC200L and AC500 have thermal protection without active preheating. The BMS blocks charging below 0 degrees and shows an alert. For the precise consumption of each appliance to optimise winter autonomy, check my power consumption table. You warm the station yourself before charging. Less automated, but the protection is there.
The Jackery Explorer 2000 Plus blocks charging below 0 degrees via BMS. No active preheating. Discharge works to minus 10 with capacity loss. Standard for the market -- adequate, but without EcoFlow's innovation.
Entry-level stations (lesser-known Chinese brands, older generations) are the riskiest. Some have no cold-charge protection at all. If your spec sheet does not mention a charging temperature range, verify manually and never charge below 5 degrees as a precaution.
If you do not use your station over winter, a few precautions apply.
Store between 40% and 60% charge. Never at 100%, never at 0%.
Store somewhere cool but not freezing. An insulated garage, an indoor cupboard, a cellar. Ideal storage temperature: 10-25 degrees. Below 0, degradation risk rises even without use.
Run a partial cycle every 2-3 months. Switch on, let it discharge 100 W for an hour, recharge to 50%. This maintains cell chemistry and prevents BMS gauge drift.
The worst thing you can do: put the station away empty in an unheated garage in November and find it in March. There is a good chance it will not switch on without a recovery procedure, and some cells may be permanently damaged.
With the right precautions, a portable power station works perfectly well in winter conditions. LFP batteries handle cold better than ever. Modern BMS units protect against charging errors. And a few simple habits -- insulate, preheat, store at mid-charge -- are enough to extend your battery life by years.
If you use your station in a van, my guide to the best station for a campervan details the models that handle tough conditions best. Cold is not the enemy of your station. Ignorance of what cold does -- that is.
Below 0 degrees, charging becomes dangerous -- that is where lithium plating can occur. In discharge, the battery works down to minus 20 but with 20-30% less capacity. Between 5 and 45 degrees, you are in the comfort zone. Below 5, start paying attention.
Bad idea. Boot temperature drops to near outdoor temperature within hours. At minus 10 outside, your station will be minus 10 by morning. Bring it inside the cabin, or insulate it with a blanket or polystyrene box. And above all, never charge it cold.
Yes, on two counts. Its crystal structure copes better with freeze/thaw cycles, and it functions in discharge down to minus 20 where NMC gives up around minus 10. However, both chemistries suffer equally from lithium plating if you charge below 0 degrees. LiFePO4 remains the best choice for winter use.
Cedric
