I'm using the NRF51822 for a project that will be powered by a lithium battery. I'm wondering if it would be safe to use a diode (such at this one) to drop the 4.2V LiPo maximum down to the 3.6V operating range. I realize I could use a Lithium Manganese battery to do this but I'll be powering up to 5 leds in the outdoors so I will need something with a larger capacity.
Would this be a safe approach or do I need some kind of regulator?