I've got one- its a really nifty little item, but I havent used the cell voltage recorder function yet, may have to do a little bench test just to see how well it works (cell voltage should still dip down a fait bit just blipping the throttle with the wheels attached). They also have an awesome wireless 2.4ghz version that lets you know the voltages whilst you are driving- now thats an epic feature, like a fuel monitor whislt you are driving so you know when to pit stop...
http://www.hobbycity.com/hobbycity/s...attery__869Mhz
Swanghobby also sell similar items, some abit funkier with LiFe compatibility:
http://www.swanghobby.com/battery-ac...ugs-c-209.html