What Will You Do If the Power Goes Out?

by Bill Norman on July 1, 2007 - 4:32pm

Summer and fall typically bring storms that cause power outages — not a comforting thought for people who rely on electrically powered equipment to breathe.

Fortunately, preparation can reduce the impact of power outages, even when hurricane-magnitude disasters strike.

Existing backup

Those who use portable ventilators already have a power option if household power goes out — the unit’s batteries. 

Many portable and nonportable vents also include a small backup battery that provides about an hour of power. Some vents have two primary batteries, so if one declines significantly, the other automatically kicks in.

How long will a full battery charge last? That mainly depends on the type of battery and how much power the medical device requires. Portable ventilator batteries are rated at anywhere from three to nine hours, but may run longer or shorter depending on external conditions.

Switching to lithium-ion batteries can add an additional two or three hours of use. These batteries also are lighter than standard lead-acid batteries, and recharge in only two to three hours.

Lightweight lithium-ion battery pack

Although some feel confident just relying on the vent’s batteries, others want another source of backup power, in case of long outages. Following are tips, precautions and equipment options for those who want to take added measures.

How much more power is needed

Many vents draw between 200 and 400 watts of power. But to be safe, the power source should provide more than the specified wattage. If the necessary power isn’t there, the device can’t perform its vital job.

Vent owners need to know the operating specifications for their particular unit when shopping around for backup power.

Use the car

One alternative is to plug the vent into the power outlet (lighter socket) in a car or van, tapping the energy of the 12-volt direct current (DC) automotive battery. Some vents come complete with a lighter socket adapter and cord. For others, after-market setups may be an option (contact the vent manufacturer).

It’s recommended that the vehicle’s engine be running during use, so its battery is continually recharging. This must be done outdoors to avoid carbon monoxide buildup, meaning the vent user probably will have to sit inside of, or close to, the vehicle.

Those planning to use this backup power approach should be sure to keep their vehicle’s fuel tank at least half full.

Solo batteries

Yamaha EF1000is portable generator

Deep-cycle 12-volt marine batteries provide several hours of electrical power. DC cables (the same type as used for lighter socket connections) and clamps (available at hardware stores) are needed to connect to the battery terminals. The vent already may have its own input connection to attach the cables, or one may be recommended by the vent manufacturer.

However, when marine batteries quit, it happens all at once with little warning. For that reason, those using this type of power arrangement should have more than one battery on hand. Also needed is a charger to ensure the batteries stay at full power during storage.

A standard automotive battery can work in a pinch, even as a stand-alone unit. But as its charge declines, electrical output also gradually declines, meaning a vent could begin hesitating and laboring because it’s not receiving all the power it needs.


Mid-range portable generator

Gasoline- and propane-fueled generators provide a steady source of alternating current (AC) electricity. There are basically three options:

    • A small, lightweight, portable “camping” generator (1,000 to 2,000 watts) will power a ventilator or related device. Typical price range: $200 to $800. 

      Yamaha EF1000is.This 1,000-watt unit produces either 120-volt AC or 12-volt DC power. Weight: 28 pounds. Cost: about $750. Runs up to 12 hours on less than a gallon of gas. Features an inverter to even out fluctuations in energy flow (see “Pure Power”).
Portable battery packs supply hours of back-up energy.
  • A mid-range portable generator (3,000 to 10,000 watts) can power not only a vent, but household lighting and appliances like refrigerators. Cost: $200to $2,500. Manufacturer-reconditioned models cost less.

    Example:  A reconditioned Generac 4000XL produces a maximum 4,000 watts and 120 and 240 volts of AC power or 12 volts DC. Runs up to seven hours on one 4-gallon tank of fuel. Price on E-bay: $200.

  • A large automatic-start generator (7,000 to 40,000 watts) fires up immediately if house power goes out. Low-end units (starting at about $2,000) may power several electrical circuits in the house, while high-end units ($10,000 to $12,000) can power the entire home. If connected to a natural gas line or large propane tank, these big units have an essentially unlimited fuel source.

    Downsides to generators are that less expensive ones are noisy and must be started by yanking on a cord. More costly units have push-button starters.

Most importantly, many generators don’t provide the consistent “medically rated” current needed for sensitive electronics like vents (see “Pure Power”).

All generators must be operated outdoors due to poisonous fumes. Generators should be tested every seven to 10 days to ensure they’re tuned and ready. Adding several drops of fuel stabilizer (available at auto parts or hardware stores) keeps gasoline fresh.

Uninterruptible power supplies

Uninterruptible power supply (UPS) systems combine a surge protector and a backup battery.

Ordinarily, a ventilator plugs directly into a wall outlet. The UPS becomes a “middle man” in the arrangement. The UPS plugs into the wall outlet; the vent plugs into the UPS. When household current is working, it sends power through the UPS to the vent. A charger in the UPS keeps its batteries up. When electrical power fails, the UPS batteries take over the job of powering the ventilator for up to several hours, depending on the size of the UPS system.

Medically rated UPS units contain powerful surge protectors that can prevent ventilators from being “fried” if lightning strikes the home.

It’s possible to combine a UPS with a gas generator. If the UPS batteries fade during a prolonged outage, the unit can be plugged into the generator, which not only provides fresh power but also recharges the UPS batteries.

Typical cost of a medically rated 1,000-watt UPS is $3,200.

Head for the hospital

Most hospitals have backup electricity-generating systems that spring into action when the main power supply is interrupted.

Vent users with limited resources for backup power should check with their doctors and/or area hospitals to see if using the facility’s emergency power is an option in a prolonged outage.

Think ahead

The secret to coping with a serious electrical power outage is to be prepared, not only with an in-depth plan for backup power, but with “rehearsals” of all the steps needed to keep critical medical equipment functioning smoothly in an emergency.

'Pure' Power

Stand-alone power inverter

Batteries produce direct current (DC) electricity that’s ideal for operating medical equipment such as ventilators.

But most generators produce alternating current (AC), and not all AC is created equal.

Household AC usually is what’s known as pure, or near-pure, sine power, meaning the current has very few fluctuations and is considered “clean.”

But AC current produced by some generators fluctuates and is sometimes described as “raw.” Raw-power units aren’t medically rated.

A split-second hesitation in the function of a refrigerator probably isn’t noticeable, but sophisticated electronics like ventilators are another matter.

To assure seamless operation, a generator should be equipped with an inverter device to produce near-pure sine energy. Of course, these medically rated generators cost more.

Alternate Power Resources

Uninterruptible Power Supplies

(800) 837-6503

Chloride Power Protection (formerly "ONEAC")

Electric Generators Direct
(800) 710-7499 (Option 2)

Micro Power Electronics
(800) 576-6177

Power Bright Technologies
(866) 295-6775

Ventilators and Battery Systems

Pulmonetic Systems
(800) 754-1914


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