I bought a cheap cordless stick vacuum on sale two years ago. It was great for about three months. Then the battery started fading — first fifteen minutes of runtime, then ten, then five. Eventually I was racing around the apartment trying to vacuum the whole place before it died, like a weird cleaning game show where the prize was a partially clean floor.

I replaced it with something better and actually did the research this time. Here’s what I learned about cordless vacuums that last.

Battery life is the bottleneck

The number on the box — “40 minute runtime!” — is measured on the lowest suction setting on a hardwood floor with no attachments. In real-world use on medium or high power with a motorized brush roll on carpet, expect half that number. More if you have thick carpet or pets.

What to look for: a removable, swappable battery. When the battery degrades after a few years — and all lithium-ion batteries degrade — you can replace it for forty dollars instead of buying a whole new vacuum. Dyson and Samsung both sell replacement batteries. Many budget brands don’t, which means the vacuum is disposable once the battery dies.

Three picks at different budgets

Budget pick: Tineco A11 Hero. Runs about $200-250 depending on sales. Removable battery, about 25 minutes real-world runtime on medium, good suction for the price, and replacement batteries are readily available. The dust bin is on the smaller side and you’ll need to empty it frequently if you have pets.

Mid-range pick: Dyson V12 Detect Slim. Around $500-550. The laser headlight that shows dust on hard floors is not a gimmick — it reveals dust you didn’t know was there, which is both satisfying and disturbing. Runtime is about 30 minutes on medium with the motorized head. The bin is easy to empty, the filtration is excellent, and Dyson sells replacement batteries. It’s expensive but it feels like it’ll last.

Splurge pick: Dyson Gen5detect. Around $700-800. Longer runtime, more suction, better at picking up long hair without tangling around the brush roll. If you have multiple pets or a large home, the extra power matters. For an apartment, the V12 is probably enough.

What to avoid

Skip anything without a removable battery. Skip anything where you can’t easily find replacement filters online — filters need to be washed or replaced every few months. And be skeptical of no-name Amazon brands with five-star reviews and “40 minute runtime” claims. Read the one-star reviews first. Those are the ones that mention the battery dying after three months.