who's got the button? You do, which means you don't have to go the drugstore when your watch, calculator, camera, radio or nearly anything else stops. Be prepared for electronic quitters with this 30-pack of button cell batteries in the most popular sizes. Our each is (6) AG1, (6) AG3, (6) AG4, (3) AG5, (3) AG12, and (6) AG13 batteries. (Some devices may call these G1, G2, etc., or have other arcane codes for these same sizes.) Brand new!

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.

Same here. But before you head outside (and we're all ready to head outside), best have a backup plan. We use this Philips 10,000 mAH Battery Pack, the size of your larger smartphones at approx 6" x 3" x thin as a Swedish pancake at 5/16". Weighs in at under 8 oz, and the rechargeable Lithium battery has 5X the juice of a standard iPhone 8 battery. Includes dual USB ports for charging two devices simultaneously, a micro-USB to USB cable, overheating/voltage/current protection, and a charging status light. Will also connect to your standard USB wall outlet charger when you come in out of the rain. (Not included)

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.

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 (but not 9-volts!). Red and black arms designate the +/- sides, and an LED at the base lights up if the battery is good.

Can you plug in a banana? You can when you have a pair of 34” black and red leads with banana clips on one end. And these have alligator clips on the other end, so you can also plug in your reptiles, too.

This power supply is made for COB LED boards, and provides constant current up to 1750mA from 10-28VDC. Features 0-10V voltage control dimming, thermistor feedback, and a separate 5-12V 2W output for a cooling fan. Has full pinout on the case. Works perfectly as a driver for COB LED lighting boards. Like these. Click! Measures 5-5/8" x 3" x 1-3/8". RoHS compliant. UL.

So you like Nickel-Metal Hydride rechargeable battery bargains? You choose a 4-pack of "AA" 2600 MAH or "AAA" 1000 MAH NiMH batteries, the recommended choice for electronics, cameras, games, cordless phones and toys.

This MW® regulated power operates on 120 VAC and delivers constant accurate power to a video game, radio, portable TV, or any device drawing up to 2.0 amps. The 5 1/8" x 3-7/8" x 2-5/8" housing has a rotary dial to designate 3, 4.5, 6, 7.5, 9 or 12 VDC output, and heavy-duty red and black binding posts. Automatic short circuit and overload protection and thermal cutoff. Add the mini plug kit or the alligator test clip leads. The mini plug kit contains six of the most popular DC plugs for DC powered devices such as portable TV sets, video games and radios. "Gator" clips are 36" long with one red and one black lead.

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.

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!

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.

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.

You should put buying new batteries in your calendar. These “AA” alkaline batteries, GP Ultra Plus+ brand, are marked as lasting until 2/24. You’ll get (4) packs of (2) batteries, which is (8) total, and yes, we know you just did that math in your head.

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.

From Velleman®, this polycrystalline, encapsulated solar cell is rated at 0.5V 800mA, and is just waiting for your hobby applications. Surely, you have something to sun-power. Measures 2-5/8” x 3-3/4” and has 5-1/2” leads.

Here's a brand new selection of sealed lead-acid rechargeable batteries, for when you're pushing something a little bigger than a penlight. All batteries are all direct from the manufacturer with current date codes. All of them have (2) 3/16" wide quick-disconnect terminals on top. Click on battery description for a photo.

These single “AA” battery holders, with springs, are in black plastic with pins ready to be mounted directly to a printed circuit board. Also have small mounting holes at each end.