What travelers need to know about batteries and battery care

AAA Battery Case, photo courtesy of InAnyCase.com

Today’s travelers are taking more and more electronic devices with them: smartphones, digital cameras, flash units, gps, world alarm clocks, laptop computers, digital tablets, mp3 players, noise canceling headsets, and others.

All these devices require battery power. Some contain built-in batteries, many do not. Some use custom batteries, others use old standbys — AAA or AA. Regardless, travelers need to know how to charge, pack and travel with batteries, and if using generic batteries, which ones should be purchased.

I’ve found that many travelers’ knowledge about batteries is seriously outdated, and many are unaware of restrictions on packing batteries for travel.

Today, electronic devices which use custom batteries generally utilize lithium-ion (Li-Ion) batteries. For devices which users choose batteries, many users continue to opt for primary (use once and done) batteries such as alkalines, while others use secondary (rechargeable) batteries, usually some kind of nickel metal hydride (NiMH) batteries.

Development of lithium batteries began in the early part of the 20th century with pioneering work done under Gilbert N. Lewis, an American physical chemist, best known for his break-through discovery of the covalent chemical bond.

While the power vs. weight potential of lithium batteries was huge, it had a serious stability problem which was finally solved at Sony in 1991, under the direction of American chemist, John B. Goodenough, with the development of the Li-Ion battery.

The Li-Ion battery allowed a major leap forward in portable electronic devices because of the amount of power it could deliver with its light weight.

Unlike the nickel cadmium (NiCad) battery, which had been the best selling rechargeable battery, the Li-Ion battery has no memory, and therefore doesn’t need to be deep discharged to retain its ability to take a full charge. Li-Ion batteries have a far lower discharge rate, when not in use, than the NiCads.

Battery professionals agree that charging lithium-ion batteries is simpler and more straightforward than nickel-based units. The charge circuits are relatively simple. Nickel technologies require analyzing complex battery signatures which can change with age.

For travelers, what’s important is that charging an Li-Ion battery can be accomplished regardless of the existing charge without negatively affecting the battery, so “topping-off” the charge is perfectly acceptable, to ensure you start the day or job with a fully charged battery.

Overcharging and overdischarging an Li-Ion battery shouldn’t be a problem because of the chargers used and the protection circuitry integrated into the battery. It is never necessary to charge Li-Ion batteries fully, and because it reduces battery stress, it’s actually better to not fully charge them.

If your Li-Ion battery or its charger gets excessively hot, stop the charge immediately. Charging should not be attempted if the temperature is below freezing.

Even if you use best practices with Li-Ion batteries, they are subject to aging, even when not in use. Tests confirm Li-Ion batteries have a predictable capacity drop over 1,000 cycles to about 80%. They continue to drop lower with each use. Eventually, the capacity will drop enough that the user will be forced to replace them.

Safe Li-Ion storage, especially while traveling, is important. The terminals of the batteries should be prevented from touching the terminals of other batteries, or conductors which could short the battery across the terminals. These batteries generally come with plastic caps to cover their terminals. Use them!

As of January 1, 2008, the Department of Transportation (DOT) through the Pipeline and Hazardous Materials Safety Administration (PHMSA) no longer allows loose lithium batteries in checked baggage. Pack all your Li-Ion batteries in your carry-on luggage.

When I travel, all my batteries are either capped and placed in padded bags or kept in high density polyethylene (HDPE) containers.

In recent years, the overwhelming choice for AA and AAA rechargeable batteries used in electronic devices has been NiMH, which replaced the older NiCad battery. The NiMH battery generally eliminated NiCad battery’s major problem of memory. The NiCads were also environmentally unfriendly.

NiMH batteries, until recently, had a serious discharge problem when not in use, however. For example, if I charged NiMH batteries for a flash unit or noise canceling headset, I could count on having to recharge within a few weeks, even if they sat in a drawer.

Fortunately, in the last couple of years, low discharge versions of NiMH batteries were developed and are widely available. All my AA and AAA batteries are now low discharge NiMH batteries.

NiMH batteries have a complex charging signature, unlike the Li-Ion batteries, so I recommend for those who use these batteries to get a quality charging device. I recommend Maha Powerex chargers exclusively. They are reasonably priced and highly dependable.

I have one final suggestion. The use of today’s rechargeable batteries, if they can be used in your electronic devices, versus “once and done” batteries, is preferable environmentally, as their use will reduce waste volume and the quantity of toxic chemicals put into our rubbish. If you can use rechargeables please do so, and don’t forget to recycle all batteries at the end of their useful life.