The Duncan Download Blog: Business Aviation Advice & Observations

Don’t Blame Your Aircraft's Battery

Posted by Diane Heiserman on Tue, Nov 04, 2014 @ 12:00 PM


 An aircraft’s battery is one of the highest-maintenance components on board. Not many other items are due every three months or 100 hours. And for organizations with heavy flight schedules, such as charter services or air ambulances, batteries could require the aircraft to be down nearly every month.

Yet this workhorse of a unit is continually ignored, left idle and unused for long stretches of time, pushed hard with low levels and occasionally allowed to deep discharge. Through it all, it is expected to function without fail.

And it is cursed when, during that one critical flight when the company’s president is on board, the battery will not crank and the aircraft and passengers are stranded.

Although the first reaction may be to fault the battery, according to Brian Teeters, aircraft battery technician for Duncan Aviation, most premature battery failures can be contributed to one thing…human error.

Purchase the Correct Battery

A well-maintained battery will provide three to five years of dedicated service, maybe even more. And that premature failure is not a defect or fault on the part of the battery, but rather on the operator for not purchasing the correct battery required for their flying schedule. 

The best battery purchase for a charter company, air ambulance or any other company that flies short, frequent one- and two-hour flights many times a day or week is not be the same battery that will provide years of faithful service to a flight department with a less demanding schedule.  

Environmental conditions are also a factor. Brian says extreme cold and hot climates, such as the northern territories of Canada or along the equator will impact the longevity and effectiveness of battery life.

Brian warns, however, that just having the correct battery for your flight operation will not prevent premature failure. Batteries still require regular maintenance and care.

Properly Care for the Battery

When asked for one piece of advice regarding batteries, he was quick to point out “most problems could be avoided if the last one out of the cockpit would simply shut off the lights.

“The number one reason aircraft batteries fail at start-up is because they were allowed to deep discharge overnight when the master switch was left on.”

An overnight deep discharge is especially devastating for lead acid batteries. When a small charge is left to pull from these batteries, even for just a few days, the cells are destroyed. There is no alternative but to replace them.

“Make sure all the switches are off before putting the aircraft to bed. It takes only a few seconds to shut it down, but many pilots miss that step,” Brian says.

To some, an aircraft battery is a simple purchase. However, based on the number of batteries that come to Duncan Aviation for maintenance and repair, it is a purchase that should be taken seriously.

Brian and the rest of the Duncan Aviation battery team see up to 150 batteries every week.

This two-room shop has every test set, battery charger and capacity gauge available to perform capacity checks, testing and maintenance for every aircraft battery in service on the various business aircraft in use today. About 75 percent of the batteries that arrive at the shop are checked, charged and returned to customers in fewer than five days, with many others in fewer than two.

He knows more about aircraft batteries than most. And he wishes operators would give batteries more credit.

Think about it. The batteries are the first component to engage an aircraft’s electrical system and the last line of defense before everything shuts down in an emergency.

You want them to work.

You need them to work.

Before making this important purchase, discuss your needs and operation requirements with a provider who has extensive technical experience and knowledge servicing aircraft batteries. Might I suggest this smart guy

Brian’s advice for getting the most out of your aircraft battery:

  • If operating with lead-acid batteries, having the electrolytes at a proper level is necessary. Too often this gets checked only once a year.
  • Make sure the master switch is in the off position before shutting down the aircraft and walking away.
  • When on the ground, disconnect the aircraft batteries and use ground batteries.
  • Use ground power assist at start-up.
  • Perform periodic voltage and visual inspections. There should be no excessive voltage difference between cells, electrolyte build-up or bulging cells.
  • Don’t ignore the 100-hour inspection requirement.


Tags: Parts & Accessories


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