Help needed, buddy not starting..

[Yamathan]

So I’m a happy owner of a buddy, however with an issue. It doesn’t start.

Egen I turn on the ignition, I can use the position and warning lights, everything else is dead. However it shows the tell tales on the dash when I use the hazard/warning light.

All other is dead in the dashboard.

All fuses are ok, nothing weird. If I unplug the fuse for the controller and plug it in again.. then the battery led turns on for 30seconds or so, showing it’s fully charged.

The battery is fully charged at 82-83v (72v system).

Attached is a picture of the vcu/controller, any recommendations on how to fault trace? If I reset it on the button then the battery meter is working again for 30seconds.

The contractor shows 20v..

Any recommendations?

 

[matzetronics]

the button then the battery meter is working again for 30seconds.

This means only that the Controller is in idle. Once you switch on the Ignition, it should display the first LED in the speed display. If that doesn't happen, the controller is not aware of the state of the ignition. There are only a few possible reasons for it, the most obvious is a missing connection from the switched 12V line to the car controller. I'm not sure if the wiring in the Buddy is the same as in El-Jet 4 or 5. But if it is, check the following Connector Pins on the car controller, according to this web page:

Anschlüsse

kewet Car Controller

www.kewet.de

Use your translator to read it in your desired language
All voltages are measured against GND on the car controller. (Pin 3 on JP1) Be careful not to short any of the pins against each other

1. On Connector JP 1 (leftmost) Pin 1 - +8 Volts from DC/DC Converter
2. On JP2 from Pin 1 up to Pin 8 - +72 V from batteries in steps of 12V down to 12V
3. On JP2 Pin 12 - +72V. If this voltage is missing, the carcontroller will not start when the DC/DC is off.
4. on JP4 Pin 5 must be +12V else the cut-off Relay is off
5. On JP4 Pin 7 Stop signal from Charger must be 12V when charger is off and car is ready to run.
6. On JP4 Pin 9 Ignition from Key. must be 12V when switched on.
7, On JP5 Pin 4 must be 12V
8. On JP5 Pin 6 must be 12V when car is on and the 12V relay K4 activates 12V circuits which are only actove with ignition on.

The website unfortunately has very little information about the buddy, as we never encountered them in Germany. All the information is from Kewet El-Jet 4 and 5; although the Citi-Jet 5 should be very close to the Buddy,

 

[matzetronics]

Still, if you are unsure of how things work (or don't work), please provide Photos of the Controller Board. This helps, as we are not very familiar with the Buddy. If you are from Norway, chances are that there are Buddy specialists in the local electric car community found in forums and chat groups.

 

[Yamathan]

Here’s some pictures, I’m located in Gothenburg.. :/

 

[matzetronics]

I’m located in Gothenburg

Oh, thats nice
To bad that Fredrik Grufman sold his El-Jet 4 - he'd be a valuable help for your Buddy. He's located in Järfälla.

Fredrik Grufman – Wikipedia

sv.wikipedia.org

It might be a good idea to contact him as he's working with electric cars.

The controller looks a bit different from the older versions but the connectors look the same. I think the pinouts are the same as decribed on the above website. Its probably best to translate the page into your preferred language, print it and then use your voltmeter to measure whats happening.
Be careful with your wristwatch to not make shortcircuits with it

 

[matzetronics]

One more note:
The positive end of the main batteries is located in front under the hood and has a lot of wires including the thick ones connected to it. First make sure that all wires are properly connected to the Plus connection and there's no loose end there. There are two thin cables going from there to the Carcontroller, one for the measuring of +72V (Pin 1 on JP2) the other provides the starting voltage (Pin 12 on JP2) for the DC/DC converter startup.

Does the controller still recognizes charging? If the charger is switched on, the capacity meter should light up, even if the batteries are fully charged. Is the 12V battery being charged?

 

[Stefanhg]

The website unfortunately has very little information about the buddy

@matzetronics I just got a buddy myself recently and Is working on restoring it. I'll try and document as much as possible I run into and see if I can try and expand the information available.
It does seem like most information available also counts for Buddy, same with the CarComputer but I'll see if I can find any differences .

And about this post in general, in order to make the display wake up, do you need to have the +72V available? I have been going through the +12V system on mine and the computer does seem to be functional, but it is also in "idle" and I don't have the +72V on it.

 

[matzetronics]

And about this post in general, in order to make the display wake up, do you need to have the +72V available?

Yes. The CarController is powered by the DC/DC Inverter and not from the resident 12V battery. To 'jump start' the DC/DC after approx. 2 days the Carcontroller feeds the 72V to a CMOS circuit which in turn activates an optocoupler to start the DC/DC.
If the car did not sleep for more than 2 days, the DC/DC keeps running.

 

[Stefanhg]

Yes. The CarController is powered by the DC/DC Inverter and not from the resident 12V battery. To 'jump start' the DC/DC after approx. 2 days the Carcontroller feeds the 72V to a CMOS circuit which in turn activates an optocoupler to start the DC/DC.
If the car did not sleep for more than 2 days, the DC/DC keeps running.

Perfect.
Either my car is just completely different from others because people fix broken things or the DC-DC converter is just changed.
On mine the:
"JP1-1 - +8V from DC/DC" is constant 12V from low voltage battery
"JP4-11 - 12V battery +" is also constant 12V from low voltage battery

DC-DC converter feeds the +12V battery directly which then charges it.
I do think it is original since the DC-DC converter have information about it being repaired.
Looking at the diagrams, I assume reason for mine is not starting is the missing JP2-12.
I am SO lucky that I got spare CarControllers and electical knowledge so i got a setup on my table I am testing things on.

I attempted to "jump start" the computer by applying external voltage to JP2-12, i assumed it not being an analog input I could just apply a low voltage signal and If i applied 12V the computer did indeed start! Im surprised about the current draw, a wopping jump from 250mA to 900mA!
I also got an display connected so i can see everything looks good! One funny detail is it thinks the car is at full capacity

Connections:
JP1-1, +12V
JP1-3 (Used JP1-10 here) GND
JP2-12 +12V (not connected here, black jumper cable)
JP4-9 + 12V
JP4-11 +12V

Then as you can see, it is alive!

 

[matzetronics]

Glad you could bring it back to life. Btw, this looks exactly like the Carcontroller for the older Citi-Jet 5. The new Buddy controllers have a smaller PCB and the Display Board is also smaller, close to yours (see the first posts here).
So i guess most of the information from my site regarding the El-Jet 5 controller match your setup.

On mine the:
"JP1-1 - +8V from DC/DC" is constant 12V from low voltage battery
"JP4-11 - 12V battery +" is also constant 12V from low voltage battery

This looks like a modification. First, the +8V should really be +8V and not 12V. This won't damage the CC, though. The original DC/DC has a seperate output circuit for the 8V.
Normally both the +8V and the +12V plus the ground wire to JP1 come from the DC/DC. The reason is that the DC/DC output is floating (galvanically free from car ground). This eases measuring voltages routed to the controller.
Problems may arise when you connect real ground wires in the car to the controller, like the shunt voltages from the current shunt.
I think that one of the former owners had a defective DC/DC and replaced it with a commonly available one. Most of the common DC/DC inverters have the same ground on input and output. The Kewet/Buddy though use this custom model made for them.

 

[Stefanhg]

Glad you could bring it back to life. Btw, this looks exactly like the Carcontroller for the older Citi-Jet 5. The new Buddy controllers have a smaller PCB and the Display Board is also smaller, close to yours (see the first posts here).
So i guess most of the information from my site regarding the El-Jet 5 controller match your setup.

This looks like a modification. First, the +8V should really be +8V and not 12V. This won't damage the CC, though. The original DC/DC has a seperate output circuit for the 8V.
Normally both the +8V and the +12V plus the ground wire to JP1 come from the DC/DC. The reason is that the DC/DC output is floating (galvanically free from car ground). This eases measuring voltages routed to the controller.
Problems may arise when you connect real ground wires in the car to the controller, like the shunt voltages from the current shunt.
I think that one of the former owners had a defective DC/DC and replaced it with a commonly available one. Most of the common DC/DC inverters have the same ground on input and output. The Kewet/Buddy though use this custom model made for them.

Thank you for sharing your knowledge!

Yeah I did actually get a 'spare' smaller contorller which I repaired (K2 relay traces was broken). One amazing advantage is that it has a buck converter so the 250mA constant current draw on +12V is reduced to 50mA!

output is floating (galvanically free from car ground)

I did just notice this now while troubleshooting it not powering on. One disadvantage surely is that between HV and LV there is in my case around 35 ohms so if you reverse something it could go really wrong as I assume this is within the CarController.

I might start a thread here to post all my details on including all photos I am taking since I do take a bunch while playing around!

 

[matzetronics]

On the Kewet site is a modification to drop the idle current of the original DC/DC to well below 60mA. This is done by changing a single resistor. This mod works for several years now on my El-Jet 4.

Indeed, car ground and carcontroller ground ist not the same. I have a big schematic for the Citi-Jet 5 available on the site.

I might start a thread here to post all my details on including all photos I am taking since I do take a bunch while playing around!

That sounds good

 

[Stefanhg]

On the Kewet site is a modification to drop the idle current of the original DC/DC to well below 60mA. This is done by changing a single resistor

The buck converter I am talking about is part of the CarController, +12V DC-
DC. The older CarController is based on good ol' 78xx voltage regulators which are inefficient but VERY reliable .
I don't know what my DC-DC converter draws of current, but I don't think it is that much. I had two power supplies connected in series to give me 62V to try and start HV part and I think I remember 22mA current draw when OFF without connecting the sense terminals to CarController, but they are rather high impedance (382K input impedance) so current draw is very minimal.

I have looked at the schematic. Kewet.de is my biggest source of knowledge and lucky enough it seems like most design choices are the same on the buddy!

 

[matzetronics]

The older CarController is based on good ol' 78xx voltage regulators

Yeah, this is also the case for the even older Carcontroller on my El-Jet 4 - not to mention the mounting of those which was a source of trouble. Like you i changed them to small pincompatible switch converters. They stay cold and are reliable without the need for a heatsink.

and lucky enough it seems like most design choices are the same on the buddy!

Judging from your pictures i think this is an older buddy from the early 20xx years. This car should indeed by very close to the Citi-Jet 5.
My biggest trouble with the controller is the display board which suffers from defective LED digits now and then. A few days ago another of those digits lost a segment.

 

[Stefanhg]

Like you i changed them to small pincompatible switch converters

Oh yeah that is also a quick and easy way of solving it!

suffers from defective LED digits now and then

That surprises me a lot! Rare that LEDs fail.
Too much current driving the LEDs?

Update on car. Batteries installed, but Motor controller is not happy. "Hardware fault" error code.
Any tips for this?

I haven't connected the sense wires for the 6 batteries, only the "JP2-12 - +60/72V supply for start circuit."
There is also a black wire under the seat. I assume that the battery 12 sense which is between - terminal and 200A fuse (to GND)

 

[matzetronics]

That surprises me a lot! Rare that LEDs fail.
Too much current driving the LEDs?

Its the old SAA1064 from Philips which drives all LEDs on the display board. I do not think this thing is able to deliver a current large enough to burn a LED. No, it think its a problem made by Kingbright who manufactured these digits. I already had a few of these digit problems. Lucky me has a display panel from a Citi-Jet 5 where i salvage replacement parts. Sooner or later i probably have to think about a microcontroller as a display panel replacement.

Update on car. Batteries installed, but Motor controller is not happy. "Hardware fault" error code.
Any tips for this?

The Curtis will not start if the throttle pot is pressed or differs much from the initlal 0k resistance during power on, also open throttle wires will trigger the fault. Plus, the KS (Keyswitch) input must be close to 72V on your car.
(if the controller is a Curtis) - Newer Buddys use a SepEx Controller iirc and not the 1209M as in older cars.

The only connection from the carcontroller to the Curtis are the relays to the Keyswitch input and the optocoupled output to the throttle pot for the ECO control ramps. If the optocoupler on the carcontroller is lit it will reduce the throttle. This is only a feature and the controller runs without this.
But these connections can be used to conveniently measure the throttle pot. It should be close to 0 Ohms in idle and close to 5k on full throttle. These wires run to JP3-4 and JP3-5 on the CC board.

 

[Stefanhg]

SAA1064

I just checked the datasheet. the drivers can be programmed to different driver currents so a new fireware could solve it.. Oh well too late

The Curtis will not start if the throttle pot is pressed or differs much from the initlal 0k resistance during power on,

Alright time to update on the troubleshooting.
- Pot works fine, Reaches 0K no problem and varies.
- keyswitch is 71V while running
- HV Relay latches as expected.
- Field coil on motor is ~4 ohms
- Verified the diode for supplying power to forward/reverse is working and fuse is not blown.

This is not good.. I also asked the guy i bought it from and he says the motor driver worked just fine when batteries were pulled out.

 

[Stefanhg]

Update.
I haven't been able to confirm it since that requires me to pull out my motor controller, but It seems like I actually have a curtis sepex 1268!
This changes everything since first error code is 2,1 which means "LOW BATTERY VOLTAGE" which plays really nicely together with a new error code 5,1 "MAIN COIL OPEN" which is the coil for the HV relay!

 

[Stefanhg]

Update again!
I found a loose cable on the HV relay!
I tightened it and now back to 2,1 but it actually worked after doing this!
Now I just gotta get that error fixed, but I am sure that relates to my lazy wiring since the cable shoes are not correct size for batteries!

 

[matzetronics]

but it actually worked after doing this!

That sounds very good. I know that Elbil Norge at one point changed to a SepEx Motor/Controller, but could not fix the date. May i ask you about the build year of your car and its exact model name?

the drivers can be programmed to different driver currents

That is correct and this feature is already used by the car controller to adjust the brightness of the display according to the ambient light measured by the 'magic eye' on the display board. But even on the highest setting this can't frag the LEDs as the chip is much to weak for that.
I see you started a new thread about your Citi-Jet 6 - very nice.