Do
Power off when the manual says so.
Match the + / − markings.
In a multi-battery device, replace all batteries together with the same type.
Keep coin batteries away from children; prefer child-resistant packaging when you can.
Don’t
Don’t force a thicker battery into a thinner slot.
Don’t mix old and new batteries.
Don’t puncture, recharge (unless designed for it), or burn disposable batteries.
After you fit it
Some sensors need re-pairing. Calculators may need a reset. Check the notes on the device page.