C7 Controller shows different voltage then actual battery.

[RGOLD]

When the controller shows empty battery the battery itself still has two lights on and the voltage is:

However, the controller show -0.7V lower:

I wonder if it's per design or a miss calibration.

 

[jkvt]

What do they both read when the battery is full?

 

[RJC]

Hi, Are you still getting power assist with controller showing that voltage.

 

[RGOLD]

Hi, Are you still getting power assist with controller showing that voltage.

Yes, full power.

 

[RGOLD]

What do they both read when the battery is full?

Will test

When the controller shows empty battery the battery itself still has two lights on and the voltage is:


View attachment 57299

However, the controller show -0.7V lower:

View attachment 57297



I wonder if it's per design or a miss calibration.

Will test soon and let you know.

 

[RJC]

Yes, full power.

I tend to go by the lights on the Battery, try to make sure not to far from home when only one light lit.

 

[jkvt]

I tend to go by the lights on the Battery, try to make sure not to far from home when only one light lit.

Interesting! I *think* the lowest I've seen the battery go is two of four lights but I also never got to the point where the power cut out. I got to the point where the display was blinking the battery symbol once and just assumed the computer was about to cut the power off before the logic board on the battery cut things off. I assumed it was a way to just get more cycles out of the battery... but then again you know what they say about people who assume!

 

[RJC]

I wonder if anyone has run to the point when the power cut off, and if the screen was still powered up and lights still showing on battery.

 

[RGOLD]

What do they both read when the battery is full?

Battery charge at full:

Controller shows 53.8V
Battery shows 54.4V

 

[jkvt]

Battery charge at full:

Controller shows 53.8V
Battery shows 54.4V

Interesting. Mine reads 53.8 when it was fully charged too. Maybe a -0.6 or -0.7v bias on the display. I think 54.6v would be a fully charged battery (4.2v*13 cells), although I'm sure 54.4 is very reasonable over that many cells.

 

[-sandro-]

Could it be it's a protection feature to avoid deep discharge?

 

[cwh060]

Don't forget, the battery is being used to run the display and power up the motor. There is bound to be a slight voltage drop when a load (the display and motor) are connected. The drop is negligible, what you really want to know, is how much power (voltage and current) remains in the battery under load. The controller will have cut off circuitry, monitoring voltage. (it's easier and cheaper to build voltage sensing circuitry).