ORIGINAL: Dr Honda
What version ECU do you have? I don't think they early ECU's will like Lipo Power. Not to mention... there is no guard in them, keeping them from over discharging the Lipo. And... as above... if you use more voltage... the pump, starter, and glow voltages will be off, and need to be re-adjusted. (for a V2 ecu)
Just throwing in my 2 cents.
Dr H is correct.
Look at the ECU and note the version and engine serial number. Email AMT the information and the question to confirm. I think that v1's are stuck with NiCd or NiMH.
Details on how to change the settings are on their website. Always change the settings with a NiCd pack. Be careful with the glow plug setting once a LiPo is connected.
There is no low voltage protection, but with a 3Ah pack you will get at least 8 flights before a charge is required and it won't start if the voltage is too low.
Regards
Dr J