Thanks to improvements in LiPo technology the 2014 cells have less internal resistance and “fall-off” late in the discharge cycle. What this means to racers is that you’ll notice that same great punch late in the race that you experienced the first time you mashed the trigger; the batteries also provide longer run times. ProTek R/C also listened to racers who wanted a race specific 4S LiPo with 5mm bullet connectors. Also they increased the capacity of the 4S “Lite” pack to 3700mah, but it’s still the same footprint as a 2S pack. Our 2S LiPo lineup includes: 7400mah, 5800mah, 3200mah (pan car), and 4700mah (shorty). There is a 6400mah 1S battery for pan car racers. All 2014 ProTek R/C “Supreme Power” LiPos now feature 5mm bullet connectors except for the 4S 4700mah (positive and negative leads) and 4S 3700mah “Lite” (features “T” style plug).
You can buy them at http://www.amain.com/