How to store a power station between storm seasons

Follow your own maker's storage figure, because they don't agree. For most stations that means leaving it switched off at around 40 to 60% charge, somewhere cool and dry inside the house, and topping it up every three months. Then, in late October, charge it to full and run the fridge off it for a while so you know it works before cyclone season.

The figures below come from the user manuals and support pages EcoFlow, Bluetti, Anker SOLIX and Jackery publish for their 1kWh models, plus the Queensland Fire Department's lithium-ion battery advice. All are linked at the bottom. We haven't stored these units through an off-season ourselves, so treat the sums as arithmetic from the makers' numbers.

The off-season is about six months

The Bureau of Meteorology's official tropical cyclone season runs from 1 November to 30 April. For a lot of Queensland households that's also when the storms that cut the power arrive, so a station bought for blackouts can sit untouched from May to October. Six months is long enough to matter. EcoFlow's DELTA 3 Plus manual says the product won't be covered by warranty if it isn't charged or discharged for more than six months, and Jackery's Australian manual warns that a station stored flat for three to six months can lose performance or stop taking a charge.

What each maker says

That's four different answers. The EcoFlow DELTA 3 Plus and Bluetti Elite 100 V2 manuals want a part charge. Anker's user guide for the Anker SOLIX C1000 says to check the level weekly, charge to full if it's under 30%, and fully charge it at least once every three months in long storage. Jackery's support page for the Jackery Explorer 1000 v2 says to recharge every three months to keep it above 50%, and lists a storage range of 0 to 45°C for three months but 0 to 25°C for a year. The Queensland Fire Department's general advice for lithium-ion batteries is about 40% for long-term storage.

Where the maker and the fire service differ, we'd go with the maker for your model, since they know how their battery management system behaves and they set the warranty terms. If your manual gives a range, sit near the low end of it.

How much power a stored station leaves you

Storing at part charge has one catch: a storm can turn up before you've topped it up. Take a 1,024Wh station stored at 60%. That's 1,024 x 0.6 = 614Wh in the battery, and allowing 15% for inverter losses about 614 x 0.85 = 522Wh at the outlets. A fridge averaging 60W would run for roughly 522 / 60 = 8.7 hours on that. The 0.85 is our assumption, and the 60W fridge is an example, so check yours with the runtime calculator.

At 40% the same sum gives about 348Wh, or nearly six hours of that fridge. Enough to get through a short outage, not a long one. So when a severe weather warning comes out, charge it to full straight away, whatever month it is.

Where to keep it

Inside the house is usually the best spot. EcoFlow gives an ideal storage range of 20 to 30°C and says never above 45°C, Anker says 0 to 40°C, and the Queensland Fire Department says to keep batteries away from direct sun, heat and moisture. Anker and Jackery both warn against leaving a station in a car or anywhere it'll sit in high heat. A shed or a closed garage in a Queensland summer can be a lot warmer than the house, so if that's your only option, leave a thermometer in there for a few hot afternoons before you trust it.

Keep it off the floor if your area floods, on a hard surface, and away from anything flammable. Switch the main power off, turn the AC and DC outputs off and unplug every cable, as the Bluetti and Anker guides say. A station left on with an output running will slowly drain itself flat.

A simple calendar

1. Late April or May: run it to the maker's storage level, switch it off and put it away.
2. August: do the three-monthly top-up or cycle your manual asks for, then put it back at storage level.
3. Late October: charge it to full, plug in the fridge and modem, and check the display shows the load you expected.
4. Through the season: keep it full and topped up after every outage.

When you charge it for the top-ups, the Queensland Fire Department's rules still apply: a hard, non-combustible surface, a ventilated spot, and someone home while it charges. Don't use or charge a station that's hot, swollen, cracked, leaking or making popping or hissing sounds. If it's been in floodwater, treat it as damaged and contact your council about disposal, and don't put a lithium battery in a household bin.

Is it still big enough?

The October check is also a good time to look at the bigger picture. If the station barely made it through last season's outages, our blackout and cyclone season guide works through a typical day in watt-hours, and the guide to running a fridge in a blackout shows where most of the energy goes. Older stations with NMC cells wear faster than LiFePO4 ones, which our battery chemistry guide covers.

Whatever you do in the off-season, never connect the station to a power point or the switchboard to back up the house. The only safe way to link backup power to house wiring is a changeover switch and inlet installed by a licensed electrician.

Quick questions

Can I leave my power station plugged in all year?

The makers' storage advice assumes it's unplugged and switched off. Some stations are designed to sit on the charger in UPS mode, so if that's how you use yours, follow the manual's section on that mode rather than the storage section.