Thanks for the replys.

I am using the battery input on the RX. I have been using it for a couple of years on 4s with no problems, I prefer to see the voltage of my batteries rather than rely on a low-voltage cutoff. It's easier to see when the power on the batteries are dropping (and time to stop/change batteries).

May be safest to just use it when I am only using 4s. Not racing with it, so stopping to check is no problem. Test it with a meter or just put the batteries one at a time in the rustler and look at the radio for battery voltage. Since I just started running more than 4s, wanted to be careful.

So far MMM and NEU 1515/1Y are lots of fun. Just have to get off the trigger finger, so it won't keep flipping on it's back.

have you tried on anything higher than 4s. I have a react on the way
:yipi:, and need to know if i should make a voltage sensor? i will run 5s, will it be safe?
thanks

Not with the voltage sensor attached. Have now run with 4S, 5S and 6S. I heard it can handle up to 21v, 5S charged = 21V, too close for me. But you could use it with 5S after running the battery for a while.