カシメ is when a blunt pin is passed through something, then squashed (pressed with a tool to flatten the end, making it larger than the hole it was passed through) to attach it securely. Some companies refer to this as Caulking (though not like a bathtub), others as Clinching.
ハンダ is soldering, so the entire sentence reads:
メーカーはハンダ仕様の電池からカシメ仕様の電池へ切り替える
The Manufacturer is switching from a Soldering Type Battery to a Caulking (Clinching) Type Battery.