A: Refurbished means the G4 has been inspected, cleaned, repaired if necessary, and tested to meet strict performance and safety standards.
SKU: BA-400
Inogen One G4 Portable Oxygen Concentrator - Open Box | Single (4 Cell) | BA
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$1,275.00
$1,299.00
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Key Features
- Description
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An affordable lightweight oxygen therapy device for home use and travel
Refurbished Inogen One G4 – Professionally reconditioned, tested, and sanitized to deliver safe, reliable, and affordable oxygen therapy in a compact design.
If you want a portable oxygen concentrator that is easy to carry and simple to use, the Inogen One G4 is a proven option. This used Inogen G4 is designed for people who need supplemental oxygen as prescribed, but also want more freedom than heavy oxygen tanks.
Because it is compact and lightweight, the G4 works well for everyday errands, appointments, and trips. It is also a popular oxygen concentrator for travel when your prescription is a match for pulse dose delivery and your clinician approves a portable concentrator.
Why choose a used Inogen One G4
A used machine can be a smart way to get an Inogen at a more affordable price, especially if you want a trusted brand without paying new equipment pricing.
A used Inogen One G4 may be a good fit if you want
• A lightweight oxygen machine for daily mobility
• A smaller unit for short outings and travel days
• A budget friendly way to own a portable oxygen concentrator
Pulse dose oxygen delivery with adjustable settings
The Inogen One G4 is a pulse dose oxygen concentrator. That means it delivers oxygen in a dose when you inhale, rather than providing continuous flow. The G4 has 3 flow settings, from 1 to 3.
Important note for buyers
Pulse dose is not the same as continuous flow oxygen. Always confirm with your clinician that a pulse dose oxygen therapy device meets your needs, especially for sleep or higher oxygen requirements.
Travel friendly design and quiet operation
One of the biggest reasons people choose the G4 is how easy it is to bring along.
Highlights for daily use and travel
• Weight: 2.8 lb with a single battery installed
• Quiet operation: 40 dBA (listed at setting 2)
• Compact size: 5.91 in (L) x 2.68 in (W) x 7.2 in (H) with single battery
• Warm up time: about 2 minutes
Airline policies can vary, so it is smart to confirm requirements before your trip.
Battery options and charging (what to expect)
Battery life depends on your setting, breath rate, and battery age. The manufacturer specs list:
• Up to 2.7 hours with a single battery (at flow setting 1)
• Up to 5 hours with a double (extended) battery (at flow setting 1)
• Recharge time: about 3 hours (single) and 5 hours (double) with AC or DC power
Used unit tip
Batteries are wear items. Even if a used unit works great, battery runtime may be lower than “new battery” specs. If long runtime matters, consider adding a fresh battery or an extra battery for your routine.
Simple controls and everyday maintenance
The G4 is built for straightforward daily use with an easy to read display and simple control functions.
It also includes a particle filter that must stay in place during operation to keep intake air clean.
Some versions support Bluetooth labeling and Inogen Connect app compatibility (listed in Inogen materials).
Specs at a glance (real manufacturer specs)
• Delivery mode: Pulse dose oxygen delivery
• Flow settings: 1, 2, 3
• Oxygen concentration: 90% +6% / -3% at all settings
• Weight: 2.8 lb with single battery
• Size: 5.91 in x 2.68 in x 7.2 in
• Noise level: 40 dBA (setting 2)
• Intended use environment ranges: up to 10,000 ft altitude, 41°F to 104°F operating temperature
• Expected life notes (manufacturer): system expected life 5 years, batteries expected life 500 full charge and discharge cycles
| Model | Delivery | Settings | Weight (lb, std batt) | Noise (dBA @ setting 2) | Dimensions (in, L×W×H) | Battery Std (hrs @ setting 1) | Battery Ext (hrs @ setting 1) | Best for | Notes |
| Inogen One G3 | Pulse dose | 1–5 | 4.8 | 39 | 8.75 × 3.0 × 8.25 | 4.5 | 9 | Value-focused portability | Older-gen model; good balance of settings and portability. |
| Inogen One G4 | Pulse dose | 1–3 | 2.8 | 40 | 5.91 × 2.68 × 7.2 | 2.7 | 5 | Lightest carry, short outings | Smallest/ lightest in this group; fewer settings (1–3). |
| Inogen One G5 | Pulse dose | 1–6 | 4.7 | 38 | 7.19 × 3.26 × 8.15 | 6.5 | 13 | Longest runtime, widest range |
Most settings (1–6) and longest listed battery runtimes. |
Buying a used Inogen One G4: what to check
Because this is a used portable oxygen concentrator, it is normal to see cosmetic wear. Before you buy, it helps to confirm:
• What is included with this listing (battery type, charger, carry bag, DC cable)
• Battery condition and expected runtime for your routine
• Return and warranty details for used equipment
• Your prescription match for pulse dose and your required setting range
The original G4 system is commonly bundled with items like an AC power supply, DC power cable, battery, and carry bag, but used listings can vary.
Need an affordable Inogen
If you are looking for an affordable Inogen portable oxygen concentrator and you are not sure whether the G4 is the right fit, open a chat with us. Tell us your prescribed oxygen setting and when you plan to use it (home, walking, travel), and we will point you to the best option.
Related parts
| Tube Connection | Cannula |
| Model | BA-400, BA-408 |
| HCPCS Codes | E1392 |
| Operating Modes | Pulse dose delivery (Intelligent Delivery Technology) |
| Altitude Adjustment | Up to 10,000 ft |
| Sound Level | ~40 dBA at flow setting 2 |
| Carrying Case | Yes |
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