Here's what I sent to Castle via email:
"Dear Castle Support, this is a final attempt on my part to communicate that, with my experience (and the testimony of others), the newer Sv2 sidewinder esc cannot handle running (serious cogging on take-off) a single 2S lipo using a parallel battery plug (y-harness for the escs). This setup is ideal for us in the clodbuster racing scene and was a great partnership with the older sidewinder esc- it was considered the way to go for a dual brushless setup. Here is another thread being discussed on rcmt.net (this is one of many)
http://www.rcmt.biz/bd/showthread.php?21349-sidewinder-sv2-issues...&p=189900#post189900
I am confident that I have properly setup and even troubleshooted this problem- I called in three times to Castle Support and also from suggestions of veteran racers. I own 4 race trucks- 2 run the older sidewinders with cm4600kv motors, 1 with the new SCT 3800kv 4 pole motors with the sv2 and now my newest one I chose to go with ezrun 60amp 5.5T.
I have attempted everything: re-setup of radio and esc,rebinding, latest firmware, rpm calibrating, timing, running 4-poles or the cm4600kv motors, higher 65C discharge quality 2s lipo, 1 red wire, 2 red wire, no red wire, external bec, using a seperate power supply for servo, digital and anolog servos, a prayer before hand---- I am serious EVERYTHING. The only way to make this work without cogging is to use a single 2s lipo for each esc.
This has been my experience and the experience of a few others that I talk with on RCMT. There are not as many guys using the new systems as are currently using the older versions- at this point I do not know of many guys who will buy the newer systems with this feedback out there. We also understand that what we do with the systems is unique and not a major demand. But I have not heard of a single person being able to run this setup- except for your resident clod guy. I recently did a new race clod build and went ahead and purchased 2 ezrun systems for my project. I prefer to stick with castle and really like the new price point of the new sidewinder systems but if they cannot do what we need them to do then we are stuck- and either need to pick up older units (more costly) or go with other brands.
Please help me Obi Wan- you are my only hope."
Here is their Response:
"Have you tried updating the ESC to the latest version for firmware with a Castle Link?
Electrically, there is no difference between one larger battery in parallel or two smaller batteries to each ESC except that with running the two separate batteries will start showing different voltage and the motors will run at different speeds. If the total mah is the same with one battery and the combined total of two separate cell to each ESC there is no difference as far as the ESCS are concerned. If you are trying to run the same sized battery using one pack in parallel as what you would run to each motor individually you only have half the power going to each motor in the parallel set up and you simple do not have enough battery to get both motors to star smoothly. You can parallel two packs together then parallel these to each ESC to double the capacity of smaller packs of this is the issue. If the mah of your single pack is twice that of two batteries, one to each ESC, there is no electrical difference so the problem has to elsewhere.
BTW, the minimum to run each system with no cogging is 4,000 mah, 30c or better. This means it will take 8,000 mah, 30c or better to get the same power to each system. This is why paralleling two packs then splitting to each system to keep the voltage the same is the best way to go. One 4,000 mah 30c battery for two motors is only 2,000 mah each which is not close to enough to get these system to start smoothly."
