Why are power tool batteries a bundle of multiple cylindrical cells rather than a brick like phone or laptop batteries? Are there advantages other than cost?

Question

Why are power tool batteries a bundle of multiple cylindrical cells rather than a brick like phone or laptop batteries? Are there advantages other than cost?

In: 26

Answer 1

My calculated speculation is that it has to do with the manufacturing volume of the tool in question and safety (to some extent). The cylindrical cells (Li-Ion cells) come in standard sizes whereas the pack kind (Li-polymer) is somewhat a custom fit taylored to the application.

If the number of units that you produce and the overall product size doesn’t justify the customization costs, it’d make sense to go with a standard cell.

The only other reason I can think of is that the Li-Ion cans being metal offer some more resistance to impact punctures. A squishy Li-Po cell is protected only by the outer case. These kind of batteries explode or at least go up in flames when punctured.