This thread is interesting for sure. With that said, I run Zippy lipos in my Savage Flux. I run the soft case 3S 3500 30C constant/40C burst and the soft case 3S 5000 30C constant/40C burst packs. 0 problems and I've run them in this truck since early February. The truck uses the stock 20/44 gearing, runs 6.5-7" tall tires and is tuned with Castlelink, specifically the throttle punch and throttle curve. The auto lipo cutoff is set to 3.5v per cell. Firmware is 1.21. The performance of the truck, even when neutered with Castlelink, is superb. The batteries never get hot and the ESC never gets hot-the fan kicks on and does its job like it should. From my experience, I'd be hard pressed to not tell somebody to use Zippy packs.

I will add that Castle really has nothing to gripe about because HPI and Traxxas both state in their user manuals that you can run anything from a 6 cell nimh stick pack up to a 25C 3S lipo with the Mamba Monster. Certain Zippys meet that requirement, and the ones I run do meet it. If Castle has a problem with us running Zippys, they need to sit down with HPI and Traxxas and get things sorted out with the battery pack particulars. And they need to let the end user know, in writing, what should be used and what shouldn't. From my perspective, it appears Castle is not on the same page as HPI and Traxxas, or vice versa. And this is a major issue considering the amount of Savage Fluxes and BL E Revos that have been, and will be sold. Not to mention all the "loose" Mamba Monsters that have been sold and installed in other kits or conversions.