How do I choose a cordless tool battery system?

The first cordless tool you buy determines every subsequent one, because the battery is the expensive part and it is proprietary.

Step by step

1. Choose the platform, not the tool.Batteries and chargers are brand-specific and often model-range specific within a brand. The first purchase locks you in for years.
2. Look at the whole range.Check the brand sells the tools you may want later — sander, multi-tool, jigsaw, hedge trimmer. A platform with three tools is a dead end.
3. Understand voltage.Voltage is roughly power. 12V is light and compact for assembly and cabinet work. 18V handles almost all domestic DIY. Higher voltages are for trade and heavy garden tools.
4. Understand amp-hours.Ah is capacity, not power. A 5Ah battery runs about two and a half times as long as a 2Ah, and weighs more. Two smaller batteries usually beat one large one.
5. Buy bare tools once you have batteries.Most ranges sell tools without a battery at a substantially lower price. This is where the platform decision pays back.
6. Check the charger speed.A slow charger with one battery means waiting. Two batteries and a fast charger means never stopping, which matters more than raw tool power.
7. Weigh brushless against brushed.Brushless motors are more efficient, run cooler and last longer, with better runtime from the same battery. Worth the premium on tools you use often.
8. Consider the budget honestly.For occasional DIY, a mid-range platform is entirely adequate. Trade-grade tools are built for daily use and the extra cost buys durability you may not need.
9. Check battery availability and price.Some brands discontinue battery formats. A platform whose replacement batteries are expensive or scarce is a poor long-term choice.
10. Store and charge batteries properly.Cool, dry, partially charged for long storage, and not left on the charger indefinitely. Battery life is where cordless tools actually fail.

Tips

• 18V covers almost all domestic DIY. Do not pay for more voltage than you need.
• Two smaller batteries beat one large one — you can charge while working.
• Once you have batteries, always buy bare tools. That is the whole point of a platform.

Common mistakes

• Buying tools on individual price rather than platform — You end up with three brands, three chargers and batteries that fit nothing else. The battery is the expensive part and it does not transfer.
• Assuming higher Ah means more power — Amp-hours are capacity, not power. A 5Ah battery lasts longer than a 2Ah on the same tool but does not make it stronger — and it is noticeably heavier.

If it doesn't work

Questions people ask