Hi Tom
If you look at the following discharge curve you can see that the cell voltage remains reasonably level until it gets near to the end of the discharge cycle:
![](http://www.arhservices.co.uk/GoldenMotor/LiFePO4dischargecurve.JPG)
The battery gauge on the BAC-601 Smart Display unit is not as accurate as a Wattmeter or Cycle Analyst as they monitor the actual battery capacity that has been used instead of trying to gauge the capacity from an almost flat discharge voltage.
I mainly run mine from a 29.6V 8 cell LiPo pack (33.6V fully charged).
I originally had the controller voltage set on 24V but I have changed it to the 36V setting which allows the regen to operate at a higher battery voltage, and the battery gauge also works much better on the Smart LCD Display:
![](http://www.arhservices.co.uk/GoldenMotor/MP4/2015-05-22%2017.25.50_zpsybqanex4.JPG)
On the previous 24V setting it always remained full even when my wattmeter indicated that over half of the battery capacity had been consumed.
![Roll Eyes ::)](https://goldenmotor.com/SMF/Smileys/default/rolleyes.gif)
Check out
this post for more information on the different battery discharge curves affect on the battery gauge accuracy.
Alan