TIP: When To Use What
Use rechargeable batteries in devices that are used regularly. Use single-use batteries in devices that are used only intermittently (such as flashlights--although best not to leave batteries inside when idle) or where a continuous drain on the cells, in standby mode, is expected over long periods of time (such as smoke detectors).

Under extreme temperature conditions, single-use lithium batteries (where applicable) are a good choice. Rechargeable lithium ion loses some performance in the cold, but it's doubtful that the camera would be in better shape under these conditions. In unusually cold climes, Ni-MH (and NiCd) would be my last choice.

TIP: Planning A Trip?
· Don't charge batteries weeks in advance of going away on a trip. The batteries will have drained by now. Charge batteries two days before--in plain sight so they're not overlooked. Why two days? So you don't forget them in a last minute rush to pack everything. Even if you've recently charged the batteries, top them off for good measure. (This applies to Ni-MH and lithium ion. NiCd batteries should first be discharged before charging.)

· If you didn't remember to charge the batteries before heading out, what makes you think you'll remember after a grueling day traveling? The realization will hit you as you're about to snap that first picture. So don't leave this till later, unless you have a car adapter and can charge them on the road.

· While chances are good you will be able to find batteries away from home, there's also a good chance you won't, or the batteries will be outlandishly expensive--or not fresh. (I've heard of a tourist being charged $200 for a camcorder battery that sells for less than half that in their local shop.) So take what you need, or more to the point, what you expect to use.

· On top of that, carry spare sets, and at least one spare set for the spares. Before departure, play tourist on your home turf, keeping track of battery usage, and use this as a gauge for the trip.

· Carrying a charger on a trip makes more sense if the charger is small and with a collapsible plug, or if you're traveling by car or going on a cruise. Luggage limitations when traveling by air, bus, or train may mean you'll have to leave that fancy charger at home. Some chargers you may need, no matter what--for the dedicated battery in your cell phone or digital camera, for instance (although anyone traveling regularly should consider buying and maintaining a freshly charged spare or two). Weigh a few sets of round cells or a few extra battery packs against the size and weight of a charger, along with the time it takes to charge and the opportunities open for this purpose. Taking a portable charger along may mean limiting yourself to an overnight charging system. A charger in your camera bag can't replace a freshly charged set of batteries or battery pack that's ready to go.

· When hiking and backpacking, be prepared to carry several extra sets of batteries. More so than airline restrictions on carryon, porting a pack on your back doesn't leave much room for extras--namely that charger. And if you can't plug it in, what's it good for? Remember, sometimes the cable or adapter-plus-cable for the charger takes up more room than the charger itself (unless the plug is built-in). If you're at a campsite or working out of a camper, or hiking or off-roading and returning to a lodge, you can leave the charger at the base site to recharge batteries upon your return. Digital cameras obviously have higher power demands than film cameras and even more than shoe-mount strobes, so carry enough extra batteries to see you through till you reach the end of the trail.

· Traveling outside the country? Buy an adapter kit, but take only those accessories you expect to use in the countries you'll be visiting. Or buy a charger designed for world travel.

TIP: What To Do When A Battery Leaks
1. I don't recall coming across a leak in progress. The chemical residue dries to a powder, and even though it may appear inert, the battery should be handled carefully--with rubber gloves, if necessary. Place in a plastic baggie to avoid further contamination. Wash hands and gloves after handling. Toss the battery, unless it can be recycled. Sometimes you may only notice what looks like a fungus growth on the terminals. That battery should be disposed of and the compartment terminals cleaned.

2. Clean the terminals inside the device by running a pencil eraser over them a number of times. Then use a bulb-blower to blow the dust out. Don't apply too much pressure with spring-loaded terminals to avoid further damage.
Spring-loaded terminals inside the battery compartment can be tricky, but chances are the leak didn't get past the immediate contact point. Make sure to clean both compartment terminals, even if only one end of the battery appears to have been the culprit.

3. Just because one battery leaked doesn't mean they all did. But don't assume the others automatically pass muster. Examine them closely.

TIP: What To Do When A Battery Leaks
1. I don't recall coming across a leak in progress. The chemical residue dries to a powder, and even though it may appear inert, the battery should be handled carefully--with rubber gloves, if necessary. Place in a plastic baggie to avoid further contamination. Wash hands and gloves after handling. Toss the battery, unless it can be recycled. Sometimes you may only notice what looks like a fungus growth on the terminals. That battery should be disposed of and the compartment terminals cleaned.

2. Clean the terminals inside the device by running a pencil eraser over them a number of times. Then use a bulb-blower to blow the dust out. Don't apply too much pressure with spring-loaded terminals to avoid further damage.

Spring-loaded terminals inside the battery compartment can be tricky, but chances are the leak didn't get past the immediate contact point. Make sure to clean both compartment terminals, even if only one end of the battery appears to have been the culprit.

3. Just because one battery leaked doesn't mean they all did. But don't assume the others automatically pass muster. Examine them closely.

TIP: Too Many Chefs...
It's great to have freshly charged batteries on hand when needed. But I've found from experience that having too many batteries is like having too many chefs in the kitchen. With too many batteries lying around, many tend to be left unused (eventually to spoil), or like a spoiled child, they demand constant attention, requiring you recharge one set, then another, and so on. So the first thing to keep in mind is not to buy too many. And cycle through sets of batteries, so none gets left behind.

Now to procedure. First, mark your calendar, just as you do for replacing batteries in a smoke detector, except do this monthly, so you'll have an established routine for charging batteries. Second, develop a system to keep tabs on fresh and spent batteries. When I put batteries away before the next round of charging, the used batteries go in the battery case head to toe, the way they went into and came out of the device. Fresh batteries remain oriented head to head--with the polarities in the same direction they came out of the charger.