Internet of Things Patterns
This is an excerpt of the pattern that was first published in [1].

Period Energy-Limited Device

Icon of the Period Energy-Limited Device pattern

Devices which are mobile or located in remote places cannot rely on fixed infrastructure. When they require a fair amount of power, use a replaceable or rechargeable energy source and renew it regularly.

Aliases:

Rechargeable

Context:

You have a device, which needs a fair amount of energy to work but does not necessarily require mains power, such as a device that takes regular sensor readings, communicates, and powers actuators. Besides, your use case dictates a specific location for this device which restricts available energy sources. For example, the device has to be mobile, wearable, or in a remote location.

Problem:

You need to power a device which requires a fair amount of power. The device is mobile or located in a remote place. Moreover, mains power is not available.

Forces:

  • Energy Needs: The device needs a fair amount of energy to work. A Lifetime Energy-Limited Device is not an option if it needs more in its life-time than current batteries offer in a reasonable form factor. An Energy-Harvesting Device is not an option if the device needs more power for a cycle than the harvesting generates between cycles.

  • Environmental Constraints: Your use case enforces a specific location for the device. For example, the device has to be mobile or wearable, or the device location is in an area where mains power is not available. Thus, being a Mains-Powered Device is not an option. Besides, an Energy-Harvesting Device is not an option if no suitable form of ambient energy source is available at the device’s location.

  • Costs: Replacing or recharging the power source is an option but has a cost associated with it, especially if the device is located in a remote or inaccessible location. For your use case, it makes economically and physically sense to do this in the time frame which allows the device to sustain its functionality.

  • Uptime: You want to minimize the periods where the device is not operating because of power source renewal.

Solution:

Use a replaceable or rechargeable source of energy to power the device. Implement a notification mechanism that informs you when the power source is nearly empty. Replace or recharge the power source when needed.

Solution sketch of the Factory Bootstrap pattern

Solution Details:

This is an excerpt of a previously published pattern. The full pattern can be found in [1].


Benefits:
Drawbacks:

Variants:

Related Patterns:

Known Uses:

  1. L. Reinfurt, U. Breitenbücher, M. Falkenthal, F. Leymann, and A. Riegg, “Internet of Things Patterns for Devices,” in Proceedings of the Ninth International Conferences on Pervasive Patterns and Applications (PATTERNS) 2017, 2017, pp. 117–126. Available at https://www.thinkmind.org/index.php?view=article&articleid=patterns_2017_9_10_70019