Topic
Batteries and runtime
Runtime depends on the battery's energy and on the power mode. Eco can last several times longer than boost, and a swappable battery doubles the time if you buy a second one.
- Energy
- Wh = V x Ah
- Swappable
- Click-in second battery
A battery's energy in watt-hours is its voltage times its capacity in amp-hours: a 25.2 V, 2.8 Ah pack holds about 70.6 Wh. The battery energy calculator turns that into kWh and pence per charge with your own unit rate.
Makers quote runtime with a non-motorised tool on eco, so expect less with the motorised head. Swappable batteries click out, so a second pack covers a larger home.
Lithium-ion packs lose capacity over the years. Store the vacuum somewhere room temperature and follow the maker's charging advice.
Guides on this topic
- How long do cordless vacuums and their batteries last?What wears out first on a cordless vacuum, why batteries lose runtime, charging habits that help and the warranty terms listed by Shark and Samsung.Guide
- How to replace a Dyson V8 batterySigns your Dyson V8 battery is worn, genuine against third-party packs, and the screws and steps to swap it safely, with checks to do before you buy a new pack.How-to
- Cordless vacuum runtime: eco vs boost explainedWhy claimed cordless vacuum runtimes vary by mode and floor head, listed minutes for Dyson, Shark, Samsung and Dreame models, and how to plan a whole-house clean.Guide
- How much electricity does a cordless vacuum use?Work out a cordless vacuum's electricity use from battery volts and amp hours, with worked Wh and kWh examples, listed charging times and why docks add a little.Guide
Buying guides on this topic
- Best cordless vacuums with a self-emptying dockSix cordless sticks with self-emptying docks from Samsung and Dreame compared on dock type, dust bags, charging, runtime and listed noise.Buying guide
- Best cordless vacuums with swappable batteriesSeven cordless sticks with removable or two-battery setups compared on batteries supplied, runtime, charging, battery platform and weight.Buying guide
- Best long runtime cordless vacuumsSeven cordless sticks with the longest maker runtimes compared on maximum minutes, mode breakdown, batteries supplied, charge time and weight.Buying guide