Best Disposable Alkaline Batteries

Alkaline batteries still best for low-powered devices like smoke alarms

Disposable batteries cost more in the long run, both for the user and for the planet, considering the environmental costs of making them and disposing of them. But alkaline disposable batteries are still cost-effective for smoke detectors, wall clocks, TV remotes and other low-powered devices that need new batteries only once a year (or less). You can save money on alkaline batteries by buying in bulk -- they'll stay fresh for years.

Most expert tests find marked differences between various brands of alkaline batteries, though some don't find much difference in performance between a household name and a cheap generic brand (with a few exceptions). One 2011 comparison test by students at Worcester Polytechnic Institute found "no measurable difference in quality" among Duracell, Energizer, Rayovac and generic alkaline batteries. "That's right, none. So just buy whatever is on sale."

In other tests, clear winners and losers emerge. The Duracell CopperTop (*Est. $5 for four AA) performs solidly in test after test and in owner reviews, which really separate the good alkalines from the bad.

Usually, when owners complain about an alkaline battery, it has leaked and ruined their device. For example, Costco's bulk-priced Kirkland Signature alkaline battery (*Est. $14 for 48 AA) earns a Best Buy nod from one high-profile testing organization, where it performs just as well as the Duracell CopperTop. But several owner reviews at Amazon.com complain that the Kirkland Signature batteries leak.

Every battery gets some leakage complaints from owners, but we found fewer grumbles about the Duracell CopperTop, which earns an average of 4.5 stars (out of 5) from owners at Amazon.com. And Duracell offers a no-leak warranty: If a Duracell battery leaks and damages your device, Duracell will repair or replace it.

The CopperTop is Duracell's cheapest all-purpose battery, but it rates just as well as the pricier Duracell Ultra Advanced (*Est. $6 for four AA) in tests at Worcester Polytechnic University and a major consumer testing organization. The Duracell CopperTop also outlasts its Energizer counterpart, the Energizer Max (*Est. $4 for four AA) , in digital-camera tests at the consumer testing organization and PopPhoto.com.

Still, for digital cameras and other high-powered devices, tests show that alkaline batteries die quicker and cost more per shot than the best disposable lithium batteries and rechargeable batteries; see our sections on those battery types.

So-called "heavy-duty" non-rechargeable batteries, also recognized as carbon zinc or zinc chloride batteries, aren't the same as alkaline batteries. According to the FAQs: Technical Battery Questions on RayovacDirect.com, "Generally used in low-drain consumer electronics, heavy-duty batteries are configured in the most common sizes (AA, AAA, C, D, 9V), as well as specialty sizes." These batteries typically don't last as long as alkalines, but they're less expensive and might be suitable for seldom-used, low-drain devices. They are difficult to find, however.

If a carbon zinc or zinc chloride battery is discharged too far, corrosion of the cathode -- the zinc shell -- can occur and the batteries can leak. This is a common cause of damage to battery-powered appliances that are left unattended for long periods with batteries inside. The electrolyte leak can also cause minor skin damage and requires careful handling.