USB 1.1 Hubs and Wall Outlets: Can You Charge Devices?
Reviving Old Tech: Repurposing a USB 1.1 Hub
Many individuals experience the annoyance of obsolete hardware accumulating dust or creating clutter. Finding a way to repurpose these devices and restore their functionality can be incredibly satisfying.
A recent inquiry posed to the SuperUser community explored the potential for giving new life to an aging USB 1.1 hub. This post details the discussion and possible solutions.
Understanding the SuperUser Platform
The featured Question & Answer exchange originates from SuperUser, a valuable resource within the Stack Exchange network. Stack Exchange is a collection of websites dedicated to community-based question answering.
This collaborative platform allows users to seek and share knowledge across a wide range of technical topics.
The Core Question: What Can Be Done?
The initial question centered around identifying practical uses for an older USB 1.1 hub in a modern computing environment.
Users explored various options, considering the hub’s limitations and potential applications.
- One suggestion involved utilizing the hub for low-bandwidth devices.
- Another proposed using it as a testing platform for USB device compatibility.
- Several responses highlighted the hub’s suitability for isolated or specialized tasks.
The consensus was that while a USB 1.1 hub wouldn't offer the speed or features of newer standards, it could still serve a purpose in specific scenarios.
Ultimately, repurposing older hardware is a beneficial practice, reducing electronic waste and maximizing the utility of existing resources.
Image credit: Alexandros Kostalas (Flickr).
Utilizing a USB 1.1 Hub for Charging
A SuperUser user, identified as user1049697, inquired about the feasibility of repurposing an older USB 1.1 hub for charging electronic devices.
The user specifically asked if the hub could be connected to a wall charger equipped with a USB outlet, effectively creating multiple charging ports.
The User's Question
The core of the question revolves around whether USB hubs function effectively when powered directly from a wall outlet rather than a computer.
The user provided an image illustrating a hub similar to the USB 1.1 hub in their possession.
I have an old USB 1.1 hub and I was wondering if it could be repurposed for something useful. Would it be possible to connect it to a wall charger that has a built-in USB outlet and use the hub to get 4 USB charging ports? Do USB hubs not work well when connected to wall outlets?
Initial testing by the user yielded mixed results.
- An older Android device (version 2.3) exhibited charging, though at a significantly reduced rate.
- An iPhone 5S, however, failed to charge when connected through the hub.
Charging Compatibility and Limitations
The observed behavior highlights potential compatibility issues when using older USB 1.1 hubs for charging.
Different devices may respond differently based on their power requirements and charging protocols.
USB 1.1 hubs were not originally designed for dedicated charging and may not provide sufficient power or support the necessary communication protocols for all devices.
The slower charging speed experienced with the Android 2.3 device suggests limited current delivery.
The complete lack of charging with the iPhone 5S indicates a potential incompatibility or insufficient power output to initiate charging.
Considerations for Hub Usage
While repurposing a USB 1.1 hub for charging is possible in some cases, it's not a universally reliable solution.
Modern devices often require higher power delivery than USB 1.1 hubs can provide.
For optimal charging performance, it is generally recommended to use a dedicated USB charger or a newer USB hub designed specifically for charging.
Understanding USB Hub Power Delivery
A SuperUser community member, Bob, provides insight into the complexities of USB hub power capabilities.
The ability of a USB hub to effectively power connected devices is heavily reliant on the specific design of both the hub itself and the device being connected. A comprehensive understanding of these factors is crucial.
Generally, simpler USB hubs lack sophisticated power management features. They typically establish a direct connection between the USB power lines and either the host computer or an external power source. Consequently, the available power is distributed across all connected ports.
However, USB charging is a nuanced process. A USB 1.1 hub will likely provide some level of charging to peripherals, but the charging speed will often be reduced. This isn't due to intentional current limiting by the hub, but rather because devices will self-limit their current draw to protect hosts that may not be capable of supplying higher currents.
The extent of this reduced charging rate varies depending on the specific peripheral and hub, but it commonly falls between 100 mA and 500 mA. This is considerably lower than the maximum charging capacity of many modern smartphones, which can exceed 1,000 mA.
Let's delve into further details:
1. If the host computer incorporates power control mechanisms, the peripheral device must establish a data connection and successfully negotiate power requirements. While technically mandated by USB specifications (excluding newer battery charging standards), not all peripherals adhere to this protocol. Most smartphones will attempt negotiation, but many simpler USB devices will not.
2. When a hub is powered by an external USB power supply lacking a proper host controller, functionality may be entirely absent.
3. The negotiation process unfolds as follows:
- Each peripheral is initially permitted to draw one unit load without requiring negotiation.
- Peripherals can request additional unit loads by communicating with the host.
- USB 1.1 and 2.0 define one unit load as 100 mA, with a maximum limit of 5 unit loads (totaling 500 mA).
- USB 3.0 defines one unit load as 150 mA, allowing for a maximum of 6 unit loads (totaling 900 mA).
4. Contemporary devices frequently demand more power than older standards allow, with smartphones often requiring between 1,000 mA and 2,000 mA.
5. The battery charging specification addresses these higher power needs. Further information on its negotiation and detection mechanisms can be found in the article "How USB Charges Just About Any Electronic Device," though its intricacies are not essential for a basic understanding.
- The charging current is capped at 1,500 mA, but only when the data lines are shorted together, or simulate a shorted state. This condition is not typically met when using a data-capable host, such as a USB hub. An additional profile exists to handle this scenario, but a USB 1.1 hub likely lacks support for it.
- Without a compatible host, more intelligent peripherals may fail to recognize a high-capacity power source and will revert to a maximum charging rate of 500 mA. Therefore, using a USB hub will likely result in significantly slower charging compared to direct connection to a charger.
6. Proprietary protocols, such as Apple's and Qualcomm's Quick Charge, introduce their own detection and negotiation methods. These protocols are also incompatible with a USB 1.1 hub.
7. The newer USB Power Delivery specification is emerging, but widespread implementation remains limited. It introduces advanced features, including variable voltages.
Do you have additional insights to contribute to this explanation? Share your thoughts in the comments section. For a more extensive discussion and additional perspectives from other technology experts, please visit the original discussion thread.