keyboard batteries still at 100% after 1 month?

[Abazigal]

Hi all,

I bought my imac about 5 weeks ago, and while I have just changed my magic mouse's batteries (and my trackpad's at 50%), I am surprised to find that the keyboard's batteries is still listed at 100% in system preferences.

Is this the norm? Any way to find out its real power?

 

[drambuie]

The keyboard battery status sounds normal to me. The keyboard power requirements are much less than for the Magic trackpad or mouse. With the trackpad the capacitive touch sensing is constantly scanning the touch surface, even in sleep mode. In addition to its touch surface, the mouse also has a power using laser. When the touch pad or mouse is being used, the power usage increases significantly. Also the bluetooth channels will be transmitting data continuously during user input.

Aside from the background bluetooth activity, the keyboard is essentially doing nothing until a key is pressed. Then the keyboard will locate the depressed key and a short keycode pulse burst lasting a few microseconds will be generated and transmitted to the iMac. Even if you're typing constantly, the battery drain of the keyboard will be minimal compared to the trackpad and mouse.

If you're using alkaline cells, the initial discharge curve is flatter, so the battery will indicate near full for a greater percentage of its discharge life than a rechargeable lithium or nimh battery.