# X144 SME Controller mysterious voltage



## HesseJames (Mar 18, 2021)

Hello together,

I am using the X144 Controller with the Netgain Hyper9 Motor. To fix mechanical problems with my adapter plate I had to uninstall the motor several times (connecting/disconecting).
Yesterday after the last removal of the engine I was hit by voltage when touching the charger's Minus cable. No charger was connected and all batteries were disconnected. All Motor cables were disconnected. I measured about 80 Volts, System Voltage is 144V nominal. I thought I created perpetual energy, but after searchng I located the origin in the Minus connections of the controller. So I wonder if this charge comes from the capacitors inside the controller? On the positive side voltage is blocked by the Main contactor, but Negative side is open - also DCDC is connected to the Negative 144V of the controller. Positive is shared with 144V precharge on the same fuse circuit. But how do those 80 Volts proceed to the Chargers Minus cable? Is that normal behaviour or is there something rotten in the state of Denmark?

best regards
Heiko


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## LSDOG (Jul 20, 2021)

If you can draw the circut and when you measure 80v it could be very helpful

If I understand right the controller is AC and his V is different is not 144Vdc but not low as 80Vac but maybe it just how the controller works


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## HesseJames (Mar 18, 2021)

It seems that the current is from the capacitors of the controler precharge. I thought there would be faster discharge of the capacitors. I did not think they hold current for so long.


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## Juiced2 (Aug 12, 2021)

I have had capacitors stay charged for months. They are very good batteries... 

Juiced racing


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