For gear with a high power drain or for devices you use often, rechargeable batteries are much more economical than disposables. That’s even after you factor in the cost of a $30 to $50 recharger, because the batteries can be recharged hundreds of times.

Our past tests have shown that rechargeable nickel metal hydride (NiMH) batteries perform better than rechargeable alkalines for digital cameras, handheld game systems and some toys.

But because NiMH cells discharge when they’re not in use, they’re not a good choice for gadgets that frequently sit idle, such as a flashlight or a remote control. In these cases, you’re better off buying batteries you later throw away.

Our recent ratings can help you decide which disposables are the most indispensable:

¢ Match batteries to gear. We tested 16 brands of AA cells in situations simulating real-world use of digital cameras and portable CD players. In addition to traditional alkaline batteries, we also evaluated lithium cells and newer nickel oxy-hydroxide batteries. We found a huge difference among battery types depending on what they’re powering. (You should follow manufacturer recommendations when selecting a battery type for your device.)

¢ For digital cameras. If you don’t want to always use rechargeables in your camera, buy lithium disposables. Best in our tests was the Energizer e2 – the only disposable to score “excellent.” Although relatively costly at $2.35 per battery in a four-cell pack, it performed three to seven times longer than other batteries.

Duracell says its new Power Pix disposable nickel oxy-hydroxide battery produces 2x

¢ For everything else. High-rated and inexpensive, Kirkland Signature regular alkaline batteries (20 cents per battery in a 48-cell pack, from Costco) are your best value for CD players or any other low- or medium-draw gear.

Although the Energizer lithium battery scored higher with such devices, it wasn’t so much better to justify its cost. Ditto for premium alkalines from Energizer (the e2 Titanium, although a better performer than the Kirkland Signature, cost $1.02 per battery for a four pack) and Duracell (its Ultra costs $1.11 per battery for a four-cell pack).

Ads for new nickel oxy-hydroxide batteries from Duracell (the Power Pix costs $1.46 per battery in a four-cell pack) and Panasonic (the Oxyride costs 85 cents per battery for a four-pack) tout their performance and value for use in digital cameras. We found that both batteries performed about the same, but neither could match the Energizer e2 lithium in powering a digital camera economically. And there were a host of alkalines that were better choices for our CD player.