Knowledge is power - in this case, battery power. You'll know from the easy-to-read gauge on this black-plastic handheld mini-tester whether a battery is good, low or needs to be replaced. The 4-1/4" x 2-3/8" x 1" tester reads "AAA," "AA," "C," "D," 9 volt, 1.5 volt button, and other sizes.

Take-outs from unused medical equipment, this package of (3) premium Duracell® Quantum "AA" batteries comes inside a plastic battery holder with 2" leads. Pop the long-lasting batteries out and use 'em elsewhere, or build yourself something. The ones we've looked at have expiration dates of December 2023, so you've got time. You'll get (6) "AA"s and (2) holders in each PKG (2).

These super handy little tweezer-style battery testers are made for checking button-cell and 3V lithium coin-cell batteries, but they've got a wide enough spread for everything from "AAA"s to D-cells. Red and black arms designate the +/- sides, and an LED at the base lights up if the battery is good.

When you run out, you have to run out and buy more. Stay home with this pack of (24) "AA" and (12) "AAA" alkaline batteries from Polaroid. Box says they're good until 2021.

This is the answer to your prayers, battery-confusion-wise. The 5-5/8" dia wheel has 44 slots and holes cut to exact size of every available button-cell and coin-cell battery for watches, remote controls, calculators, cameras, mini flashlights, audio devices, key fobs, etc. Slip the battery through the smallest hole it will go through in the plastic template and actually know what size to buy without having to put the old one under a microscope to read the numbers you can't read.

The pentapack: You pick a pack of (5) 3V lithium coin cell batteries, CR2025 OR CR2032, still in their packaging, for a price that looks like a single battery, because you're smart enough to shop here. Looking for a large quantity? Try our bulk pack of (20) batteries for huge savings!

Our each is (4) of the blue plastic "D" Cell modular battery holders, approx 3-3/8" x 1-7/16" x 1-1/8" deep without tabs. They slide together either side-to-side or end-to-end or any combination of both, with connecting tabs in both directions. Can be wired parallel or in series. Open tops. Interesting possibilities.

Nice, new 6-volt lantern batteries from Ultralast®, labeled for the international market. Standard 2-5/8" square x 3-3/16" high, standard spring tabs on top. Advanced Heavy-Duty the label says. We'll price it to save you a world of dollars, pesos and francs, Pat says.

Nice little battery holder made to contain (4) “AA” cells. Measures 2-1/2" x 2-3/4" x 3/4" with a pair of 5-1/2" leads and an SPST slide switch. The cover closes with screws so all those AAs won’t go flying around where you can’t find them if you drop it. Great for science fairs.

Generic batteries that stand up to the big boys! These are very good alkaline batteries, and they seem to last just as long as the name brands when tested against them. Our each is a pack of (1), (2) or (4), depending upon the cell size.