Desperately Seeking Power: How to Find Your Way Through the Battery Jungle

Video craves action, which is difficult to accomplish when your camcorder is tethered on a leash. So you venture timidly into the jungle of on-board DC power products to try to determine which options will give you the most juice for your dough.

What follows is a survey of camcorder battery products, listed by type so that you can easily locate the battery–and price–that best suits your needs.

Battery Species

If all camcorder batteries were the same, you probably wouldn’t be reading this article now. All you’d have to do is choose one made by a reputable manufacturer and that fit your budget. But there’s a forest of battery types available and although it takes some time to become familiar with all of them, the variety of technology is also a blessing. Each type has its pros and cons and if you select carefully, you can optimize your free-range shooting.

You can buy replacement batteries from your camcorder’s manufacturer but you’ll probably find more options and price ranges offered by accessory battery manufacturers. Some of these companies are Maxell, Eveready, Bescor, Cool-Lux, NRG Research, Frezzolini Electronics, Lenmar and Recoton. Duracell recently entered the camcorder battery market with a few models.

There are two long-standing camcorder battery types in use today, and a couple establishing themselves in the marketplace. Lead acid and nickel cadmium (NiCd) are reliable and somewhat cost-effective standbys; nickel-metal hydride (NiMH) and lithium ion (Li+) are gaining popularity, due to their increased efficiency over older battery types.

Before you make any purchases, you need to consider the type of battery that your camcorder uses. Many DV camcorders and newer Hi8 models use 8-volt lithium ion batteries, which have an excellent power-to-weight ratio; many 8mm and VHS-C camcorders, on the other hand, use 6-volt batteries of nickel-cadmium, nickel-metal hydride or lead-acid composition. Full-size VHS and S-VHS generally require 12 volts, often provided by lead-acid or nickel-cadmium batteries. As always, check your owner’s manual or visit the manufacturer’s Web site for your particular requirements.

Old Standards

Lead-acid batteries have been around so long (since the 1800s) that it might be easy to dismiss them as outdated technology, but they have many features that make them reliable power sources. They shrug off extreme temperatures, last for years when cared for properly, and are relatively inexpensive. Also they don’t suffer from “memory effect” (more on this misnomer for a NiCd-specific fault later).

The downside to a lead-acid battery is its weight, its short cycle life and its propensity to lose output voltage steadily as it discharges. If you shoot video infrequently, generally use a tripod instead of image stabilization, and don’t use many accessories which pull power, then lead-acid batteries should fit your needs.

The basic lead-acid battery is constructed of lead and lead-oxide plates encased in a sulfuric-acid gel (hence the nickname “gel-cell”), sealed in a leak-proof housing. How leak-proof that housing is makes a difference in the lifespan and safety of the battery.

Unfortunately, plates that are designed for standby use–a battery which is constantly charged and only occasionally discharged–aren’t good for camcorders. Camcorders are a constant discharge device. The chemical changes that occur during discharge can cause standby plates to fall apart when used in cyclic mode, which is how camcorders use battery power. The change manifests itself as battery failure and/or an early loss of charge capacity. There are also variations in cyclic plate design. Some are better at high rates, some at low. Using a low-rate battery at high rates can cause premature battery failure. Camcorders need a high rate battery, you must be careful when choosing a lead acid battery for camcorder usage.

Lead purity is also important to battery lifespan, although the amount of impurity necessary to make a difference is very small (.001 percent). Batteries made in Japan and the US are ostensibly the purest. Unfortunately, lead purity isn’t published with battery specs so you’ll have to take the manufacturer’s word for it.

The electrolyte system is the primary component of lead acid battery design. There are three types in sealed lead batteries: wet cells, gel cells and starved electrolyte. Wet-cell batteries must be charged and discharged in an upright position, which makes them inconvenient in some shooting situations. Gel cells avoid this problem by using electrolyte that is converted to a semi-solid, making it more resistant to current flow than non-gelled batteries. The downside of this effect can be seen if you use an on-camera light; the light will turn yellow before the end of the battery’s discharge. Bescor offers several gel-cell batteries, including the 12-volt BP-50 ($30) and BP-65A ($35), and the 6-volt BP-30 ($32). Of course, dropping any camcorder battery isn’t going to lengthen its life and if the battery casing cracks, both wet and gel cells will leak, possibly causing acid damage.

Starved-use liquid electrolyte is soaked into plates and a sponge-like separator is inserted between them, keeping it moist inside the housing. This gives you the advantage of a wet cell (your light won’t turn yellow) and the convenience of a gel, which can be used and charged in any position. Starved electrolytes also don’t have enough moisture to leak if the casing cracks. These batteries also have better shock resistance because the plates are packed tightly into the housing.

Nickel-cadmium (NiCd) batteries have also been around a long time, dating to the early 1900s. Their energy density is greater than lead-acid batteries, resulting in about 20% to 50% lighter weight; however, their cost is proportionally higher. NiCds deliver a steady voltage, dropping off only at the end of their discharge load, helping to maintain consistent accessory performance. Bescor makes a NiCd for nearly every camcorder, ranging in price from $19 to $44.

No Thanks for the Memory

The so-called “memory effect” of NiCds is a controversial term that has caused heated discussion in the video world. The term originated from a battery’s seeming propensity to “remember” the point of the last discharge and reset the battery’s internal memory to that point. If you use only 30 minutes of a one-hour battery’s cycle before recharging, so the theory goes, then the battery would subsequently hold only a 30-minute charge.

Instead of the term “memory effect,” it may be more accurate to call the phenomenon “voltage depression” because the problem actually occurs when a battery is overcharged. After a NiCd is fully charged, the charger continues to send a slow charge through it. This trickle charge alters the chemical structure of the battery, causing parts of it to discharge at a lower rate, say, 5.4 instead of 6 volts. When a camcorder that requires 6 volts of operating power reaches the portion of a battery that is discharging at 5.4 volts the camcorder’s circuits could interpret this voltage depression as insufficient and shut down. The longer the battery stays on trickle charge the more of it is affected.

Some manufacturers push “no memory” batteries that deliver an extra volt, which does not hurt the camcorder but also does nothing to insure against voltage depression. A less expensive cure is to not overcharge your batteries and don’t discharge them all the way before recharging. A NiCd discharged down to zero volts could explode. Consider a battery refresher, built into some chargers, that leaves about a volt per cell when discharging.

Both lead-acid and NiCd batteries are serious environmental hazards, so do your part to keep them out of landfills. Some retailers will recycle camcorder batteries or you can call the Rechargeable Battery Recycling Center at (800) 822-8837 or visit www.rbrc.com.

New Power

New battery technologies coming up fast include nickel metal hydride (NiMH) and lithium ion (Li+). They’re more expensive than lead acid or NiCd and each has its own pluses and drawbacks. Of the two, NiMH is the most promising.

Compared to NiCd, NiMH is not as hazardous to the environment, has a comparable density, and costs just a little more. It supplies about 20% more power than a NiCd for about 500 charge/discharge cycles, re-charges in an hour and can tolerate a broad temperature range. Bescor makes several NiMH batteries (BP975NMH and BP77NMH, $43 each). Duracell offers the DR-10 and DR-11 and Lenmar makes NoMEM models from $38-$61.

Lithium ion batteries recharge in about an hour and aren’t prone to NiCd’s voltage depression. They self-discharge at a slow rate of only about 10% per month, the lowest of any rechargeable battery on the market. Bescor has several lithium ion batteries ($59-$109) for major-manufacturer camcorders.

Another option for a backup to your main battery is the type that consists of a simple housing for regular AA batteries. Although expensive (because they’re not reusable), this type is handy in a pinch, especially if you’re miles from a wall outlet and need a quick source of power.

Charge On

A battery may unlock you temporarily from the confines of a wall socket, but you’ll have to return eventually to recharge the beast. That’s when a battery is most vulnerable and when you often have the least patience. Since some batteries, lead acid in particular, can take up to 12 hours to recharge, manufacturers have designed fast chargers to speed up the process. Unfortunately, you can only plunk a battery that was specifically designed to handle a speedy charge onto a fast charger. NiCd batteries not designed for a fast charger could even explode.

To give a lead acid battery a long life, do not fully discharge it. For example, if you use it to 50% of its capacity before recharging, the battery should last approximately 300 recharges more than if you always use it until the camcorder shuts off. And no matter how tempted you may be, never fast charge a lead acid battery. Recharge them as soon as possible after use and store them fully charged. If they’re hibernating for a long time, top them off every few months.

In mirror contrast to lead acid, a NiCd’s life is downright racy. Some can be used with fast chargers and others are even self-charging. NiCds should be stored in a discharged state. Remember, to avoid voltage depression don’t overcharge a NiCd, discharge it completely or put one not built for the fast life on a quick charger.

The type of charging device and how you use it has a great impact on the lifespan and performance of a battery. Over charging, under charging, fast charging–all can cause a battery to perform less than optimally and sometimes damage it irreparably.

Never try to utilize a charger designed for one product with another; especially not a lead acid charger with a NiCd battery or vice versa. Some newer batteries also use sensors to share information with the charger to which they are connected to monitor temperature, voltage, etc., so you’ll need to match battery to charger.

Lenmar’s Omnisource 10-12 Battery Charger/Reconditioner ($54.99) promises a fast charge for 9-, 10- and 12-volt NiCds, reconditioning, an LED display and automatic shutoff. The Omnisource JR “Swiss Army Charger” offers the same features for 6-volt batteries, plus a tester. Bescor’s BCX-1AC ($42) and BCX-2 ($48) will also charge quickly and refresh NiCd batteries.

Safari Power

If you often enjoy shooting in the wilderness, you might want to invest in a solar charger. NRG offers the Power Belt and Campak Pro Solar Chargers for about $250.

For a camcorder that will be traveling abroad, consider a charger that can adapt to worldwide voltages without an external converter. Some units can be switched between one or two worldwide voltages such as 110 or 220. More sophisticated units automatically adjust for any incoming voltage worldwide.

For the Prosumer

For those who shoot hours of video and/or need a lot of accessory power, the options are plentiful. For heavy-duty hand-held power, look to off-board (not mounted directly to the camcorder) belts, vests and packs. Belts are designed to hold from one to several batteries in a cloth housing that is worn around the waist; they are available in a wide variety of configurations. Since your back takes the brunt of the heft, look for the lightest weight model that will do the job for you. NRG Research makes the Anchor Power Belt series ($190-$320) for beginning videographers. Cool Lux has created a Pro-Budget series of lead acid and NiCd styles ($225-$475).

Vests work on the same principle as belts, just in a different clothing configuration. NRG makes two vest styles: the Power Vest Event ($560-$660), made of black tux fabric, and the Power Vest Field ($570-$670) for everyday use.

Instead of being worn on the body, battery packs or “bricks” are designed to be carried to a convenient place near the camcorder, thus weight is not as critical as wearable power sources. Sizes, types and prices vary widely. Bescor, NRG Research and Cool-Lux offer dozens of models which range in price from $80 to near $400.

Absolute Power

After the purchase of your camcorder, batteries may be the second most expensive item in your shooting kit. Although it may be tempting to go for the lowest priced power source, there are several other battery features that contribute to its cost. Capacity, discharge rate, useable lifespan, safety and the type of video you make all contribute to the cost per use.

Do you shoot for hours at a stretch, intending to edit later, or do you shoot conservatively for in-camera editing? Do you make frequent use of power-hungry components such as lights, a large LCD viewfinder or zoom lens? Is your camcorder usually mounted on a tripod or do you prefer the mobility of hand-held shooting? Given the range of battery options available now, there’s something to fit every videographer’s need and wallet.

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