Will Bluetooth 4.0 actually reduce battery drainage on smartphones?

Question

One major drawback that always made me reluctant to using Bluetooth in apps was the battery drainage factor. With Bluetooth 4.0 and the low-energy hype, I've started to change my position. But after reading up on it more carefully, I've gotten the understanding that smartphones currently delivered with Bluetooth 4.0 run a so called dual-mode, implementing Bluetooth 4.0 capabilities ontop of a regular Bluetooth controller. This would mean that the battery drainage the Bluetooth controller would have on the device won't change much with Bluetooth 4.0 (note: I'm not interested in data transfer, just idle/scan).

My question: Will a Bluetooth 4.0 supported smartphone be able to broadcast its device name and scan for other devices more energy efficiently than predecessing Bluetooth supported models?

Answer 1

If you are looking only for BT LE functionality, BT 4.0 will reduce battery drainage but as on smartphones they support both classic and LE, they will consume more battery for sure