Costco's Kirkland AA Batteries Vs. Sam's Club Member's Mark Batteries: Which Should You Buy?

Lithium is one of the key components in the rechargable batteries that power our devices these days, but a lot of us are still picking up those disposable AAs to pop into our clocks and toothbrushes. One of the top reasons people still use them is that disposable batteries are often rated to sit in cool, dry places for five to ten years, making them perfect for flashlights and other tools you'd pack into an emergency kit. For some people, that means closeting a giant pack they bought from a wholesale shopping retailer like Costco or Sam's Club.

Many times, people choose store-branded batteries, such as Costco's Kirkland Signature or Sam's Club's Member's Mark. Which might lead you to wonder which of the stores offers the better purchase. 

If you focus on price, go with Sam's Club. The retailer's Member's Mark imprint offers a 66-count package of AA batteries for $18.48, or 28 cents each. Costco's packaging goes up to 48-unit packs, and in those cases Costco's Kirkland Signature AA and AAA batteries come in at $16.99, a whopping 99 cents cheaper than Sam's Club Member's Mark.  $17.98 — 99 cents more than Costco. If you happen to be in the BJ's camp, a Berkley Jensen 48-pack costs $17.99.

Beyond any other factor, though, the best reason to pick up a Member's Mark 66-pack is arguably because it comes in a compact cardboard box. The Kirkland 48-packs in particular come in single-cavity blister packs which have been criticized in customer reviews for their poor integrity.

Wholesale clubs are in the retail business, not the battery manufacturing business, so they rely on white-label agreements to get name-brand goods in bulk sizes under the Kirkland Signature or Member's Mark banner. 

In the case of Costco, former CEO Craig Jelinek actually went on record in 2016 with WSB-TV, saying Duracell made Kirkland batteries. Considering that both Kirkland and Duracell offer the same 12-year shelf life guarantee, it's likely that is still the case. Meanwhile, longtime consumer reporter Jeff Rossen says Walmart subsidiary Sam's Club gets its Member's Mark AAs and AAAs from Energizer — both share a slightly longer 15-year shelf-life guarantee. If, after comparing the two, you prefer a brand name logo on your battery, Costco does stock Duracell-branded batteries, charging $20.99 for a 40-pack of AAs or AAAs. Energizer AA and AAA cells can be found in 48-packs at Sam's Club for $24.98.

Costco and Sam's Club go head-to-head in plenty of departments besides just batteries. Once you're stocked up on those, you may want to look at our guide to navigating the electronics section at both warehouse chains too.