Does anyone know if there is an issue when using Lipoly cells with brushed ESC's. I read in a post that there is a problem but it didn't say what it was.

Grant

Yes, the normal Low Voltage Cutoff (LVC) on most ESCs is somewhere around 5 Volts, leaving you enough power to maintain control of the airplane to land it.

LiPoly batteries will become damaged if their no-load voltage is drawn down below 2.8 Volts per cell. Notice that 5 Volts is less than 2.8 Volts in anything but a one-cell situation. Most of the time, we use two cells or more. With two cells, the LVC should kick in at around 5.6 Volts. With three, it should kick in at around 8.4 Volts.

Luckily, it's not much of a problem. Most planes become unflyable long before the voltages are drawn that low. If you're careful, you can use your existing ESCs and not damage your batteries. When the airplane starts to drop off on power, it's time to land.

Oh yea, I knew about that issue, the one I'm talking about seemed to have something to do with the frequency output of the ESC. I don't know why a battery would care what the frequency is but that is what I believe they were talking about.

Grant

Onlky thing I can thnk of is that the slightly higher internal resistance of te Li Polys might upset some brushless controllers as long pack wires do, but that is cured with a capacitor across the pack imput wires to the ESC.