Choosing a Cordless Battery System: What to Weigh Up Before You Buy In

Most cordless tools only work with their own brand's batteries. When you buy your first tool, you're really choosing a battery platform for years to come.

1. Start with the tools you'll need

List the tools you'll use now and in the next few years: drill, impact driver, saws, grinder, trimmer, blower, mower. Check the brand makes all of them on one battery platform.

2. Voltage

• 12V tools are light and compact for small jobs.
• 18V (often sold as 20V max in some markets) is the most common all-round platform.
• Higher-voltage or dual-pack tools suit mowers, chainsaws and heavy saws.

See the 18V vs 20V Max Label Check.

3. Pack sizes

Small packs are light for drills and drivers. Big packs give more run time for saws and outdoor tools. Plan a mix.

4. Chargers

Fast chargers save waiting on big jobs. Check charger output and whether it can charge off solar or a power station.

5. Cost over time

Batteries are a big part of the cost. Compare kit prices, bare tool prices and the cost per watt-hour of packs. Try the Battery Cost per Wh Calculator.

6. Adapters

Adapters between brands exist, but they can bypass protections and void warranties. Don't plan a system around them. See Battery Adapters Between Brands.

7. Quick summary

• Pick the platform that covers the tools you'll need.
• Mix small and big packs.
• Compare cost per Wh, not just kit price.

Follow your tool and battery maker's instructions. Don't open a pack or a mains-powered charger, and recycle any pack that is swollen, burnt, leaking or damaged.

← Back to all guides