Household & Alkaline Batteries

These are the ordinary cells that everything else on a jobsite runs on — the ones nobody thinks about until a meter dies mid-test. Alkaline AA, AAA, C, D and 9V cells cover flashlights, radios, detectors and the bulk of handheld instruments, and they are the right choice where a device is used regularly and the cost per cell matters. Lithium cells are the other half: a lithium 9V lasts far longer than its alkaline equivalent in a smoke detector or a test instrument and holds voltage better in the cold, which matters for anything living in a truck through winter. CR123A and CR2032 coin cells power the smaller electronics — non-contact voltage testers, laser levels, calipers, remotes and key fobs — and are the ones most often missing when they are needed. Shelf life is the quiet argument for buying ahead: modern alkaline and lithium cells hold their charge for years in storage, so a box in the van costs nothing and saves a trip. Check the device for the cell it takes before ordering; the coin cell numbers look alike and are not interchangeable.

Buy in bulk for the cells that get used and singly for the ones that do not. AA and AAA move fast enough in any shop that a 24-pack is consumed before shelf life is a question; a CR2032 multipack will outlast the device it was bought for. Lithium AA cells weigh less and hold voltage flat right to the end, which matters in a laser level or a thermal camera where an alkaline's sagging voltage shuts the instrument down with charge left in it. Do not mix chemistries or old and new cells in the same device — the weakest cell reverses and leaks. Pull batteries out of anything going into winter storage, and keep a labeled bin in the van rather than loose cells in a drawer, where contacts short against each other.