Best and worst battery buys

HOUSTON (KTRK) -- When you're finishing up your holiday checklist, there's one item you don't want to leave out - batteries.

AAs are the most popular size, so Consumer Reports ShopSmart magazine sifted through test results, to find out which will keep you all powered up for less.

"We have so many toys with batteries, I feel like we're constantly changing batteries, all the time," said mother Nicole DeFillippo.

You could spend a bundle on batteries and still wind up with duds.

Consumer Reports put 15 AA batteries to the test, both lithium and alkaline, to help you get the most for your money.

In the lab, batteries are connected to machines, which cycle them on and off, over and over, simulating use in both toys and flashlights.

The most expensive alkaline tested was the Panasonic Digital Power, and it came in last.

With the top two performers, you get almost two hours more power. Both of those were lithium batteries - The Energizer Ultimate Lithium and the Energizer Advanced Lithium.

However, they cost more than $2 per battery. For people who use a lot of batteries, Consumer Reports ShopSmart magazine found some good, less expensive options.

"Lithiums last a long time, but you'll pay a lot more for them. Plus, we found some long-lasting alkalines and they cost a lot less," said Jody Rohlena with Consumer Reports.

The Duracell Quantum AA alkaline batteries give you almost the same amount of hours in both flashlights and toys as the top-rated lithiums, for about $1 each.

The Kirkland Signature AAs from Costco are the biggest bargain, at just $0.27 apiece. They kept up with the Duracells in toy tests and gave up less than a half an hour of use in flashlights. Both will keep you rolling along, for less.

To make batteries last longer, there's no need to store them in the refrigerator, but Consumer Reports says it does pay to store them in a cool, dry place.