I recently came across a wireless keyboard with a friend of mine and I would like to buy one, what is the maximum operating speed? Are there any rechargeable battery powered types that I do not have to buy a battery to operate? What would be the price estimate of such? Which one is the best ?
Availabilty of a wireless keyboard with rechargable battery
The wireless keyboards are those that allows you  to communicate with the device with the help of radio frequency(RF), Infrared(IR) or Bluetooth. These type of keyboards communicates signals which have the range from 27 MHz to 2.4 GHz. Now-a-days most of the wireless keyboards are operating at 2.4 GHz speed. There rechargeable batteries available for wireless keyboards. There are different types of wireless keyboards like standard size wireless keyboard, portable keyboard with touchpad, roll-up wireless keyboard, mini wireless keyboard. There many companies available in the market. You may choose according to your requirement in your budget.
Availabilty of a wireless keyboard with rechargable battery
I am just giving you a link in which you can find the Wireless Keyboard which have the battery and you can recharge it. Also led wireless keyboard are available you can buy them also. Which contain all the keys and easy to use you do not need to have bought. The full keyboard. Below is the link for that.