Motivation:

The lithium-ion batteries in all of our portable devices require careful attention to ensure that they reach their potential lifetime. To achieve this, most manufacturers advise against elevated temperatures and high states of charge for prolonged periods of time, yet many of us leave our devices on charge all night. Charging all night causes the batteries in our devices to spend a significant proportion of their lifetime at full capacity and raised temperatures, highly detrimental to their health.

Charging all night means we wake up to a fully charged device, but in a world where our environmental impact is an ever-growing concern, maximising the lifetime of our device is imperative. As manufacturers move to designs where battery replacement becomes harder, batteries become the first point of failure for many devices. ProCharge delays your device's charge, to maximise its battery's lifetime.

Solution:

ProCharge is compatible with any device that charges using USB (Type A). It sits between your current USB outlet and charging cable to control your device's charge cycle.

With ProCharge's default settings, your device will start charging after 6 hours, and stop charging after 2 hours. This significantly reduces the time your device's battery spends fully charged, and at raised temperatures. ProCharge also prevents your device from fast-charging, a technology that should only be used when necessary, due to the increased stress it puts on the battery. With ProCharge's built-in mode button and status LED, you can adjust the delay and charge time to suit your needs.

Features:

ProCharge's compact form-factor includes a reversible Type-A USB plug, standard Type-A USB socket, status LED and mode button.

• The reversible USB input optimises compatibility with USB outlets.

• The top and side visibility ensures that the status LED is always visible. Its minimal brightness prevents ProCharge keeping you awake at night.

• The raised profile and tactile feel of the mode button allows for easy use, even in the dark.

• The mode button and status LEDs are used to programme and start the timer. Delay and charge timers can be set, started and skipped.
• The disconnected USB data lines enable secure charging from any public USB port, protecting your personal data. Additionally, this disables fast-charging modes.
• The low power standby mode consumes the same power in a year, that a 50W light bulb consumes in under 20 seconds!

Specifications

• Current rating: 2A
• Voltage rating: 5.5V
• Dimensions: 39x16x10mm
• Case material: 3D printed white PA2200 Nylon
• Timing accuracy: ±1s per hour
• Standby power: 30uW (0.00003W)
• Insertion lifetime: >10,000 insertons
• Button lifetime: >30,000 presses