Battery Power Stations for Home Backup

A battery power station is a lithium battery, an inverter and a set of outlets in a box. It does nothing a generator cannot do, and it does several things a generator fundamentally cannot: run indoors, make no noise, produce no exhaust, need no fuel stored in the garage, and switch over fast enough that plugged-in equipment never notices the outage.

The reason the whole category exists for home backup is that most outages are short and most essential loads are small. If the problem you are solving is "keep the fridge cold and the phones charged for eight hours", a battery solves it better than any generator at any price.

The one number to understand: watt-hours

Generators are rated in watts, which is a rate. Batteries are rated in watt-hours, which is a quantity. A 2,042 Wh battery can supply 100 watts for roughly 20 hours, or 2,000 watts for about one hour, minus inverter losses of perhaps 10-15%.

That table is the whole decision. Batteries are excellent at small loads for a long time and poor at large loads for any length of time. Working through your own numbers is the point of how long will a power station run a fridge.

Where batteries lose to generators

• Motor surge. A well pump wants 2,000-plus extra watts to start, and almost no portable battery will supply it. A fridge compressor's 2,200 W surge is near the limit of a 2,000 W unit — check the surge rating, not just the continuous one.
• Sustained high loads. Air conditioning, electric heat, an electric water heater. The arithmetic simply does not work.
• Long outages without recharging. A generator with fuel runs indefinitely. A battery runs until it is empty, and then it is a heavy box until you can recharge it.

That last point is why solar matters, and why several units here are sold as solar kits. 400 W of panels will not refill 2 kWh in a day in real conditions — angle, cloud and winter sun all take their cut — but a partial daily recharge turns a one-day battery into a several-day one.

What to look at, in order

1. 1Surge rating, if a fridge is the point. 3,000 W of surge starts a compressor; 1,500 W may not.
2. 2Idle draw. A unit left plugged in for months wasting 25 W costs real money and tells you how seriously it was engineered. The best here publish 4 to 6 W.
3. 3Cycle life. LiFePO4 is standard now and claims range from 3,000 to 10,000 cycles. At the top end this is a buy-once purchase.
4. 4Recharge speed, which decides whether a two-hour grid restoration is useful. The fastest here is 43 minutes to 80%.
5. 5UPS switchover time. Under 10 ms means a fridge, modem or home office never sees the outage at all.

Avoid comparing on capacity alone: a 1,024 Wh unit with a 2,000 W output and a 49-minute recharge is a better outage machine for many people than a 2,304 Wh unit with 1,500 W output that weighs 72 lb. Start with the main roundup, or go straight to best power station for a refrigerator if that is the actual problem.