ECU is auto sensing, 6, 7, 8 NiCd or 2/3 LiPo.
I use 3 cell LiPo

You just need to change menu 90 to 6,7, or 8 cells for the battery alarm.

If you are using 2 cell LiPo, select 6
If you are using 3 cell LiPo (recommended), select 8

Regards