Cordless Circular Saw: What Pack Size Do You Need?

A cordless circular saw is one of the hungriest tools in the shed. It spins a big blade fast through timber, so the battery you put on it makes a real difference to how many cuts you get and how well it cuts.

1. Why saws need more from the pack

Drilling a hole takes a few seconds. A long rip cut through hardwood holds the motor under heavy load the whole way. That draws a lot of current, and small packs heat up and sag in voltage, so the saw slows down and the pack's protection may cut it out.

2. Pack size guide

2Ah: fine for a few cross-cuts in pine. Expect it to run out quickly and get warm.
4 to 5Ah: the sweet spot for most home and workshop cutting.
6Ah and up: best for decking, sheet goods, hardwood and long rip cuts.

Larger packs usually have more cells side by side, which shares the load and keeps them cooler under heavy draw.

3. Things that change how many cuts you get

The timber: hardwood and wet timber take far more energy than dry pine.
Depth of cut: a 45mm-deep cut takes more energy than a 19mm one.
The blade: a sharp blade with the right tooth count cuts faster and uses less battery. A blunt blade wastes energy and heats the pack.
Feed speed: forcing the saw makes it work harder. Let the blade do the cutting.
Brushless or brushed: brushless saws usually get more cuts from the same pack.