This post originally appeared on WearableFOMO.com.
One of the chief complaints heard from consumers owning an Apple Watch is its low battery life and constant need for recharging. Reviews like this are daunting during the consideration phase, and I’ll admit they’ve swayed me away from purchase thus far as well. Because, although Apple touts an 18-hour battery life in its marketing materials, TechRadar testing reveals much lower battery life when the wearable is used for other applications than simply telling time (see below).
This begs the question: what if some of the wearable’s energy-intensive operations could be done elsewhere, offsite, in order to save battery life? This idea was recently explored in a July 2015 study released by Microsoft, WearDrive: Fast and Energy-Efficient Storage for Wearables. The study may have garnered little media attention, but it serves as a critical foundation for how we develop wearables and plan for their operating capacity in the future.
The study sought out a solution to save battery life on wearables by tackling their chief challenges and constraints:
- Small batteries – restricted to 1-2 Watt-Hours vs. 7-11 Watt-Hours batteries in our phones.
- Energy overhead of legacy platforms – manufacturers use the same chips in wearables as they do phones to simplify hardware and software development, leading to energy challenges on smaller batteries. Encryption of private data using this legacy method is also energy-intensive.
- New applications – existing wearables with small batteries can provide limited data analytics for new applications that require extended display or sensory analysis.
- Reaching the phone – wearables require a new mechanism (beyond bluetooth and wifi direct) to connect them to phones with the ability to maintain low-power, high energy-efficiency data transfer.
- Slow flash – as slow flash storage wastes energy by keeping the CPU active for longer periods of time, Microsoft proposes wearables actively use only DRAM (local and remote) to speed up storage operations.
The solution presented by Microsoft researchers is WearDrive, a fast storage system for wearables based on battery-backed RAM and an efficient means to offload energy intensive tasks to the phone. Translation: Large, energy-intensive tasks are done on the phone, while small, energy-efficient tasks are done locally using battery-backed RAM. New data is asynchronously transmitted (using a combination of bluetooth and wifi) to the phone when near proximity to the wearable device, where the phone performs the high-energy operations and encrypts the data for security in its local flash.
The results are impressive. According to their tests, WearDrive improves wearable application performance by up to 8.85x and improves battery life up to 3.69x – all with very low impact to the phone’s battery life (0.21%–2.09%).
Although WearDrive succeeds in increasing battery life for wearable applications, it still contributes to a fractured mobile customer experience (CX) for users who wish to have full functionality on their wearable, regardless of proximity to their smartphone. Apple Watch users are already aware of the “snapshot” functionality provided by its apps as compared to their full-featured smartphone versions, and these miniature experiences are only compounded (and, further jilted) when real-time data processing and updates are relegated to our phones for computation and storage.
The benefits offered by WearDrive are huge when considering its effect on wearable battery life and secure data storage, and consumers will take note of prolonged battery life when considering wearable purchases. But, we can’t stop there. Savvy developers must use innovations like WearDrive as a foundation for future hardware and software development on wearables that achieves both energy-efficient operation and provides a full user experience – with or without nearby phone pairing.
Jaimy Szymanski 