FMS 1400 mm warbirds & 5s batteries

[OsideRCflyer]

Will 5 s batteries work in the FMS 1400mm warbirds with stock setup? My 4s batteries are getting tired and I have 12, 5S batteries I use in a 78”Extra. A friend uses 5s batteries in one of his and he says it’s just fine. Any other input would be appreciated.

[fhhuber]

You need to check the ESC and motor ratings, then do wattmeter tests.

If the ESC and motor are rated for 5S, then you can expect to need to reduce prop diameter and/or pitch to prevent overloading.