Here are a few budget-friendly lipo suggestions for the 1/16 E-revo.
A big thanks to corracing for taking the time to ask Traxxas customer service about the 1/16 E-revo's battery compartment dimensions.
I'm sure most of you are familiar with Tenergy, a decent battery company offering relatively inexpensive products. I've had great experiences so far with their NIMH batteries.
There's a store on E-Bay called All Battery Center that deals primarily in Tenergy batteries. The following lipo batteries will fit according to corracing's dimensions, recorded straight from Traxxas representatives:
11.1v 2000mah lipo
Dimensions: 34mm x 19mm x 100mm
Continuous discharge rate: 30A
Burst discharge rate: 40A
7.4v 1300mah lipo
Dimension: 87.5 x 35.5x 12 mm
Continuous discharge rate: 25C (32A)
Burst discharge rate: 50C (65A)