How Many Appliances Can Be Powered With One Battery Backup?

Supporting Multiple Appliances with One Backup Power Solution

What is the only thing better than making sure one of your key appliances has backup power? Making sure that all of your most critical appliances have emergency backup power.

Access to instant and reliable backup power for your facility’s most critical appliances is a game-changer. Having an entire suite of equipment backed up allows for physicians and staff to delegate more effectively and manage more urgent needs when the power goes out.

As such, it’s common for clients with many appliances to ask how many—small or large—they can power with a single battery backup generator.

The benefits are obvious.

Having one system means you can save:
  • Time
  • Space
  • and Money
    ... right?

Not always.

And having 8 A/C outlets available means you can always plug in 8 appliances?

Definitely Not.

In short, the number of appliances your system can power depends on the amount of power that your inverter can provide (in watts).



How Do Inverters Effect Generator Output?

An inverter takes DC power stored in batteries and converts it into usable AC power. The amount of power an inverter can deliver to an appliance(s) is expressed in watts. Similarly, the amount of power needed to run an appliance is expressed in watts. An inverter cannot supply more wattage to appliances than it is rated for.

This means it is not guaranteed the inverter can handle the extra load of appliances outside of the original scope of your order. Even if the unit has available A/C outlets, extra loads may overload the system when it begins inverting. The result will be a full system shut down and failure to deliver power to any appliance during an outage.

Therefore, backing up an extra appliance with a battery-powered generator is not as simple as plugging it in. Each Medi-Products system is carefully sized by our experts to custom-meet your needs. This ensures that your unit can supply enough power to run your original appliances for as long as needed.

How Do I Find the Right Size Backup Generator?

The number of appliances that can be powered with a singular system will vary based upon the individual needs of every client.

As discussed in greater detail in another learning center post—What Determines the Cost of Battery Backup—the same factors that determine cost also determine how many appliances backup generator can power.

These include:

  • How Much Power Each Individual Appliance Needs to Startup (a.k.a. Startup Wattage)
  • The Total Amount of Time You’d Like to Provide Backup Power
  • Each Appliance’s Energy Efficiency
  • The Total Number of Available AC Outlets on Each Backup System (when available)

In the case of the first three, the number of appliances you can power wholly depends on what you're powering. Specialized equipment like ultra-low temperature freezers require massive amounts of power relative to their size, while small surgical tools do not utilize nearly as much.

Sizing a Backup Power Generator for Medical Cold Storage

Temperature excursions

Standard refrigerators or freezers have duty cycles of about 30%. This means their compressor—which produces the cold air—operates 30% of the time. Therefore, it draws power 30% of the time it is plugged in—about 7.2 hours per 24 hour day.

Meanwhile, most ultra-low temperature freezers have a duty cycle that can exceed 80%. This means they are drawing over twice the amount of power of a more standard medical refrigerator. This means an ultra-low temperature freezer will draw power for over 19 hours a day.

Even though cold storage appliances do not draw power 100% of the time, the startup wattages required to engage their compressors is often double their rated wattage. Because every system is custom-sized and built, unless planned in advance, it will likely not have much extra overhead to power other appliances in the event of an outage.

In this scenario there are three popular choices should you need more backup power:

  • Choice one is to order a newer and larger system to accommodate any extra appliances.
  • Choice two is ordering the extra appliances their own, custom, backup power system.
  • Choice three is to look into buying newer, more efficient appliances.
    Potentially, their new power specifications may meet those of the existing backup generator.

Each has their own pros and cons. Though, we often find that the second and third choices are often easiest and the most cost efficient.

Even if spatial limitations are a concern, the vertical, cabinet-like design of a Medi-Products generator allows it to fit almost anywhere. They occupy about the same space as a person, so having two in a singular room to supply backup power is a cinch.

Sizing a Backup Power Generator for Surgery and Operating Rooms


Meanwhile, when proving emergency backup power for an operating room, it's nearly guaranteed that multiple appliances will be powered at once. This is because the smaller appliances often deployed don't use much of an inverter’s wattage capacity.

One modestly sized hardwire unit for example, can power an array of lights, monitors, and small surgical tools. This due to both the efficiency of modern LED technology and the short, bursty, power draw of surgical tools. This means the inverter rarely needs to provide its peak power rating and the batteries are not being quickly drained.

Larger appliances such as a surgery table can often be powered by the same system as the lights as well. This is because they're only used for a few seconds at a time. Also, when the table is being raised or lowered, other, more power-hungry appliances are often not in use. Thus, unused appliances are not using any of the inverter's available wattage capacity. Additionally, while they're not very power efficient, because they're used for only a brief moment, they won’t drain the batteries either.

This highlights the biggest misconception about backup power—that you need an exceptionally large system to power lots of appliances. We won’t need to calculate the power consumption of every appliance, running at full capacity, for as long as you want.

Instead, we calculate the power consumption of your appliances based on realistic use—plus a little extra. This ensures you're only paying for the amount of power you'll need. The extra capacity ensures in extreme cases operations continue as normal.

Can I Utilize All The AC Power Outlets On My Generator?

Standalone and Mobile unit product lines are outfitted with 4 and 8 separate AC wall outlet inputs, respectively. These are found on the sides of the standalone unit and the front face of the mobile. All available AC outlets are of the grounded, 3-prong variety.

The available number of outlets does not reflect the number of appliances every unit can power. That is figured out when sizing a system, as mentioned above. The available outlets are only how many appliances could be powered if the system were properly sized.



Note: Hardwired units do not have built-in AC outlets. Hardwired units integrate directly into a building’s electrical circuits. Once wired, they supply power directly to targeted outlets

Should you feel you need outlets available, please inform your sales representative at time of sale. They will be able to find if a more custom solution may be available to you.

Support For Existing Customers:

For assistance in calculating if your battery backup generator can support additional appliances, call MediProducts Technical Support at:

Phone: 1.800.765.3237
Monday-Friday 8:30am-5:00pm (EST)

Find Out What Size System Your Brand New System Will Be

Every system built fits directly with the need of every customer both in power and form factor. The quickest way to find a perfect system for you is to contact MediProducts directly.

To speak to our product experts, engineers, and sales teams about quoting a system, and adding an alarm system contact us via:


Monday-Friday, 8:30am to 5:00pm (EST)


Have Further Questions?

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