ResMed S9 Series CPAP DC Converter

SKU: 36970


S9 Series DC Converter 24v 90 Watt Output

This Product DOES NOT Require a Prescription

Product Description

The DC/DC converter 24V/90W Output supports the use of Heated Humidification and a ClimateLine™ Heated Tube with a S9 Series CPAP or VPAP™ Machine while running off either a 12V or 24V DC power source. It will automatically switch for either DC power source

Previous makes of a DC converter did not promote the use of a ClimateLine™ or Heated Humidifier, but this item allows those to be used.


  • Only use the converter when connecting to a 12V or 24V DC supply.
  • Do not connect an S9 device to a 12V or 24V DC power source while the DC power source is being charged from AC mains.
  • The converter must only be used with S9 devices to ensure proper performance of the device.
  • The converter is intended for use on 12V or 24V negative ground systems (where the negative terminal of the battery is grounded). Using it on a 12V or 24V positive ground system may damage the S9 device and the vehicles electrical system. If you are unsure whether you have a negative ground system, consult the power sources manual.
  • Do not leave the converter connected to the power source when the S9 device is not in use, as this may discharge the battery over time.
  • Make sure the converter is not covered during use, to avoid damaging the device.
  • You must have an electrical system in good condition. Have it checked by an auto electrician if in doubt.
  • The converter is not intended for use on an aircraft. Using the converter

Seen on Image 2

1. Before connecting the converter, ensure the switch (1) is off.

2. Position the converter on a level surface, with the ResMed logo facing up.

3. Plug the connector end (2) of the converter into the DC input socket (5) on the S9 device.

Connecting Via a Cigarette Lighter

1. Remove the cigarette lighter from the vehicle socket.

2. Plug the cigarette lighter adaptor plug (3) on the converter into the vehicle cigarette lighter socket.

3. The light (4) on the converter will glow green when the connection is made and the switch is on. Your S9 device should then power on.

The light will flash continuously if the connection is not made, or if the device is in standby mode or power save mode when the connection is made. If the battery is low, the light will turn amber. If the light does not operate, check that the switch on the cigarette lighter adaptor plug is on.

Included in this Package

  • (1) DC/DC Converter 24V/90W Output for S9 Series Machines
  • (1) DC Cable with Battery Clips

Optional Accessories

  • H5i™ Water Chamber
  • S9 Disposable Filters
  • SoClean CPAP, Mask and Tubing Sanitizer

Recommended Replacement Schedule

  • Tube Hose: Every 1-3 Months (or as needed)
  • Foam Filters: Every 1-3 Months (or as needed); wash weekly
  • Ultra Fine Filters: Every Month (or as needed)
  • Water Chamber: Every 3-6 Months (or as needed); wash daily

Special Features

  • Some vehicles require the ignition key to be turned to the accessories position to provide power to the cigarette lighter socket.
  • If you connect your S9 device to a powered converter, the converter may power down. To resume power, turn your converter off and on again via the switch on the cigarette lighter adaptor plug.
  • If the battery AND your vehicle are not in good condition, there may not be enough reserve left in the battery to start the vehicle after use.
  • ResMed does not recommend frequent use of the standard automotive cigarette socket to power your S9 device. A standard vehicle battery is not optimized for frequent heavy discharges.

There are no user-serviceable parts inside the converter.

  • If the converter cuts power to your S9 device when starting your vehicle, disconnect the converter from the vehicle, wait a few seconds, and then reconnect it.

Ratings & Reviews

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10/8/2021 11:33 am

my husband loved it

by Barb -

I bought this for my husband and he loved it! we took it on our camping trip