Kt P5 setting

RogerA

Pedelecer
Jun 21, 2021
60
20
I've just installed a kit comprising an Aikema 100CST motor, T-06s controller, x-go 36V 13AH battery and KT LCD4 display. It's all working but I've found a slight issue with the P5 power monitoring setting. The manual says 0 is real time voltage with the controller identifying the battery voltage, and 5-15 are manual settings for a 36V battery.

I set this to 0 at first, but with a fully charged battery (41.9V) the battery mimic is showing it as empty. I think it may be identifying it as a flat 48V battery rather than a fully charged 36V one.

I've set P5 to 12 and it's showing a full battery symbol now.

The manual doesn't explain what the value of 5-15 actually is, so I don't really know if 12 is correct. Can anyone explain what the number means, and how I identify what is correct for my kit.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
P5 if using the setting 5 -15 is a rough guide to your battery usage, you will have to experiment with the setting figures so that it might represent your battery usage via the bars shown. It might be of use on lcd's that don't have a voltage read out like the lcd1 or 2 model otherwise those which do have a voltage readout just ignore it and be guided by voltage.
 

RogerA

Pedelecer
Jun 21, 2021
60
20
Thanks Neal,

So it's a bit trial and error until it shows roughly correct?

I've only ridden it round the block so far to check it's all working, so I'll keep an eye on it when I go for a longer ride. There is the voltage display on screen 3, but I guess the battery icon will be a useful indicator if I can get it showing something sensible.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Yes trial and error.
42v will show all bars , jiggle the setting 39v you should see approx 3 bars and at 37v you should see 2 bars, etc.

The voltage indicator is the more important fuel gauge.
 

Sturmey

Esteemed Pedelecer
Jan 26, 2018
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Ireland
There is suppose to be a formulae that the
P5 value indicates the voltage at which the last bar disappears, and that is U = LVC + P5 / 3.77. The other bars are suppose to scale proportional.
So for example, if lvc is set at 30v and p5 is set for 12, the last bar disappears at 30+12/3.77 = 33.2 volt approx. However, there is some smoothing and measuring to minimize misreadings under heavy load due to sag i.e. I think this applies to the battery voltage when not on heavy motor load.
When p5 =00, the voltages are as below (I think),
and 36V battery:
> 36.5 volts 4 of 4 bars
36.5V - 35.2V 3 of 4 bars
35.2V - 33.6 2 by 4 bars
33.6V - 32.2V 1 of 4 bars
32.2V - 31.0V 0 of 4 bars
31.0V - 30.4V bar border flashes, undervoltage shutdown.
 
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vfr400

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Jun 12, 2011
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You can set P5 to whatever value you want. It doesn't affect anything important. All it is is a damping coeffivient to stop the battery charge indicator going up and down with the voltage sag when you draw power. The bigger the value, the slower it responds. The values in the formula are only advisory.

There is often a delay in the KT LCDs before they pick up the battery voltage correctly. I normally have to ride about 50 meters before my battery shows full after charging.

In summary, there was no problem. It would have sorted itself out as soon as you started riding.