dbateman

My Feedback: (31)

My son is building an EDF. He has the Castle Creation Pheonix 60 amp ESC. He is set up for both 4s2p and 5s2p depending on which packs he uses. Tonight he cooked his second expensive receiver trying to test run the setup. The instructions say the unit has a bec that can handle up to 12 cells. What is the deal with lipos and these speed controllers. This is getting expensive quickly. Can someone explain please? Thanks Doug

jooNorway

The number is 12 NiCd-celles not LiPo`s! 4S LiPo is appr 12 cells NiCd.

First of all: connect the motorbattery (4S) , no prop on the motor and do not connect the receiver. Then measure the voltage on the cable form the ESC which is to be plugged to the reveiver, the red/black wires. Is this voltage OK? (Appr 5V) Are you 100% sure you have not plugged anything in at wrong polarity?

If you plan to go with 5S LiPo you should buy an UBEC at once, the BEC-circuits in the ESC`s are lowcost linear regulators. Even at 4S an UBEC delivers a much better voltage and you have less chances to get noise from ESC in to your RX. If you install an UBEC remember to remove the red wire on the cable between RX and ESC thus disconnecting the internal BEC in the CC ESC!

Matt Kirsch

My Feedback: (21)

Yes, the BEC on the Castle speed controllers is designed to handle the voltage from 12 NiCd or NiMH cells connected in series, not "12 cells" period.

Actually, the voltage from a 4S LiPoly is approximately equivalent to 14 NiMH cells. Even with a 4S, you are exceeding the BEC's capacity, and you should disable it by pulling the center pin from the receiver connection to the ESC, and taping it off.

The problem is that the BEC regulates the voltage down by burning off the excess as heat. When the difference between the main battery voltage and the 5V needed for the receiver gets too large, the BEC gets overloaded. It may be burned out even now, and connecting receivers will only continue to burn them out too. At the very least, disable the BEC and use a receiver pack or a UBEC as recommended above.

A UBEC is a different kind of regulator, called a switching regulator. The BEC in most ESCs is what's called a linear regulator. The main difference is the UBEC regulates voltage by switching it on and off very quickly, and as such can handle much higher loads and much higher voltage differences. Why don't ESCs come with switching regulators? They're expensive; they'd add $60 to the cost of each and every receiver across the board, which would put the receivers right out of most people's price range.

dbateman

My Feedback: (31)

Thanks to both you guys, very helpfull indeed. Lets go one step further , does the speed controller create more heat when flying at partial throttle because it's resisting full current flow to the motor? I always thought full throttle would create more heat and load on controller. Thanks again, Doug