Batteries, already the Achilles heel of mobile devices, present an even bigger challenge for even smaller devices, like wearables and the budding Internet of Things industry. These latter devices are not things that you would, or should, associate with the frequent charging and battery replacement we are used to on smartphones. How do you balance performance and battery life? Atmel, a micro-controller manufacturer based in San Jose, may have the answer. Its new ultra-low power SAM L21 32-bit ARM-based MCU (micro controller unit) is advertised to last more than a decade before needing a recharge or replacement.