The issue of battery life when using mobile instant messaging applications has cropped up from time to time on various discussion forums. As it’s clearly important to our users, I thought I’d dedicate this blog post to explore this topic in more detail.

We take battery life seriously at Palringo. It’s one of our key design considerations. We’re constantly evaluating and implementing ways to reduce Palringo’s impact not only on battery life, but also on CPU usage, memory footprint, and data usage.

We invest time in scientific measurements and analysis. We regularly carry out battery run-down tests on multiple devices, logging the discharge curves and analysing the impact of changes we make. We have developed some clever algorithms that make sensible selections of power saving strategies and optimise sleep/wake duty cycles to optimise battery efficiency. We constantly refine these. The exact findings and algorithms we use are Palringo trade secrets, however I can assure you we’ve developed a thorough understanding of power management across all our supported platforms.

Sometimes we need to make trade-offs. For example, increasing the interval between “keep-alive” packets reduces data usage and improves battery life. Unfortunately, it also causes loss of connection to be identified and handled in a less timely fashion. We’ve analysed our statistics and selected optimal settings which maintain good battery life without compromising the ‘instant’ nature of Palringo.

Some general points:

Power Management on Windows Mobile Pocket PCs (not smartphones) sucks. Pocket PCs use a lot of power unless they are in ’suspended’ mode. Counter-intuitively, letting the Pocket PC suspend too often wastes power – the transition between modes requires several seconds of intense CPU activity. While Palringo makes educated guesses on when sleeping is likely to be beneficial, there’s only so much that can be done. Hopefully, things will be improved in Windows Mobile 7.

3G is a major battery killer. Keeping a 3G data connection open drains the battery in record time, even if no data is sent across it. Hopefully the next generation of chipsets will be better. Until then, some users may prefer to disable 3G whenever they don’t need it.

Activity also has a large impact. Being a member of many busy groups, or having hundreds of contacts which constantly change status requires more notifications to be sent down the wire. We have some great ideas for negating some of these effects, and these will be implemented in future versions.

We’re committed to writing efficient, streamlined and robust code, an art we believe is sadly being forgotten. We’ve made some great innovations in this area, and have plenty of great ideas for future builds. Stay tuned.