While on Hangtimes site check out the voltmagic. I've been using it two years as a gas gauge for my A123's and it works very well. Just like a voltwatch for nicd/nimh, it also does some other cool things.
Also the DLE20 weighs 29 ounces with everything except battery, lots of fliers are using an ignition battery eliminator with great success. The Saito 125 weighs 25 ounces and requires 3 times the fuel load, and 15% of it stays stuck to the bottom of your plane, and yes the DLE 20 is out pulling the Saito 125. A simple use of the search button will find the numbers.
http://www.voltmagic.com/ Works for A123, check for life
Steve at Hangtime has been great to deal with. I have his battery's in my planes and my TX. Cheaper battery's out there but none better in my opinion. Good luck.