Bluetooth 4, how do we take advantage of its low energy features? I have a iPhone 4s, the last version of 17" macbook pro, mac mini 4.1 purchased in early 2010 I think, with multiple trackpads and multiple Apple BT keyboards. 

When using a keyboard with the 4s (which I know is BT 4) my keyboard battery lasts for months, the same with my macbook using external keyboard and trackpad (I thought my macbook was BT v2.xx but cannot find the product page for some reason), my mini (which I use most often) the batteries last about a month or less.

From system report
My minis BT firmware is v41 c822, the macbook is v41 c821, not really my main question but have these machines been upgraded to BT 4 via firmware update?

So now to my real question, when looking for BT devices how does one know if the device will take advantage of BT 4s' low energy features.
Low Energy requires both ends to be updated. Apple has a knowledge base article explaining this at:


https://support.apple.com/en-us/HT202880 - iOS and iBeacon requirements


For Mac, open System Information and select the Bluetooth section on the left. If you have the following line towards the top, you are equipped for Low Energy bluetooth:


  Bluetooth Low Energy Supported: Yes


Magic Mouse 2, Magic Keyboard and Magic Trackpad 2 all support low energy bluetooth as well.