Solar, Battery or Dual Power

How a calculator is powered decides how it behaves on the day you need it.

Dual power is the practical answer

Most desk and scientific calculators use a solar cell with a backup battery. The cell handles ordinary room light, and the battery covers dim conditions and the moment of switch-on.

Pure solar

Cheaper and fine in a bright room. In poor light the display dims or the machine simply stops, which is an unpleasant surprise mid-calculation.

Battery only

Common on graphing models because the screen draws more power. The trade is that it will eventually go flat, usually at an inconvenient time. Know which cell it takes before you need one.

Long storage

If a calculator will sit unused for months, take the battery out. A leaking cell ruins the contacts and ends the machine.