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Battery Basics, Part 1

Battery technology has evolved significantly since the days of the nickel-cadmium pack. But while newer chemistries like nickel metal hydride and lithium-ion, coupled with advances in charging circuitry, have all but consigned NiCad batteries and trickle chargers to the shelves of the Smithsonian, many videographers mistakenly cling to a very outdated power practice.

Back in the early days of portable power, NiCad users were encouraged to fully discharge their batteries before recharging in the somewhat misguided belief that this would prevent “memory” problems. And while letting a camera operate until it shuts itself down because the battery voltage dropped below a preset threshold can do no harm, this technique is a total waste of time for anyone using contemporary chargers and battery packs.

Sophisticated sensors and circuits built-in to the bricks and chargers work in tandem to ensure a safe and rapid return to full capacity for any battery, regardless of its state of charge. Memory problems (if they ever existed), where a battery pack “forgets” how much power it is capable of delivering and signals that it is out of juice, are a thing of the past.

Videographers intent on fully discharging a battery have been known to rush the process by leaving a camera-mounted light switched on. This well-intentioned act can have fatal consequences; because the load does not automatically switch itself off—as is the case with a camera—the battery voltage is brought far below the manufacturers’ intended limit and the potential for premature cell failure is greatly enhanced.

The bottom line: Never intentionally kill a battery by leaving a load connected. Put your batteries on charge after each use. Top-off unused batteries every few days by charging them too.

If you’re interested in the real lowdown on battery “memory,” the folks at Anton/Bauer spend three pages (47-49) discussing it in their comprehensive and very informative Video Battery Handbook.