Kewet Buddy City-Jet 6 Restoration

[Stefanhg]

Hello ,

I bought a Kewet one week ago(roughly) and thought I wanted to share some information about the car and show the progress. I am planning on restoring as much as possible on the car to a nicer condition but primary goal is to get it up and running and get it passing inspection.

Known state of car when i got it:
Car has no batteries, but everything else should be functional.

So with that in mind.. Never mind I don't trust people SO I wanted to completely test everything and isolate as much as possible.

And after running around looking at the whole car I made the following bucket list:
- Verify sunroof waterproof
- Gas spring trunk replace
- Label saying "missing power" under steering wheel
- Plastic around right speaker broken
- Figure out solution for black plastic that are very soft
- Figure out where the "kill switch" is connected
- Buy rain cover
- Light contact both doors not working
- Bracket for trunk has small cracks
- Blink indicators in front of car not working
- Blink indicator left side not working
- Test oil boiler
- Figure out constant current draw, relay clicking in trunk
- Remove reed relays put at handbrake and window trunk (mod)
- Make a better solution for light in trunk (mod)
- Pass inspection
- Plates for cars!

So with all that in mind. Time to start testing!

 

[Stefanhg]

Figure out where the "kill switch" is connected

The "kill switch" was an additional mod that was connected in the panel at the steering wheel. The old owner said you had to turn it on to activate the car. I did not get any nice pictures of it, but kill switch was basicly just a male and female spade plug which was unconnected. I assumed it was designed for connecting between charger and car so you could disconnect the "Kill" function in CarController

 

[Stefanhg]

Figure out constant current draw, relay clicking in trunk
+Testing +12V system
This surely was an interesting journey

First goal was to verify that there was no surprises. I grabbed my adjustable power supply and put it on the +12V system I tested each of the wires from battery to check the current draw and everything looked good. SO connected it all and had a small current draw of 350mA and instantly a relay latching.

I didn't know this before looking, but realized I had an additional +12V battery for the LV and starting the car so I went out and bought a +12V charger for charging it. But for now I tested using +12V power supply.

Initially I only started testing without key in, I wanted to figure out whis weird relay thing latching so I started looking around, I ended up realizing there was an aftermarked mod (indicated by random 230V cable used for wiring), I started unplugging it to see what it affected and there was no clear indicator.



It had two 230V cables. One two wire that connected to a REED switch at the handbrake, and the other I never figured out where it went. goes up the right side panel in the trunk, I have been guessing it was connected to the door switch but I can't figure it out.
This ended up being connected to a mod trunk light and the connection on the light was completely broken so I just ripped it all out.
Some day I'll take the panel off and figure out where that 3 wire cable goes to.

 

[Stefanhg]

Gas spring trunk replace

This was actually the first thing I "resolved" because it was such a big problem. Since the spring holds up the trunk, I was so frustrated while testing.
I took a cable tray and cut a small piece of it, then using the cover piece to keep it in place. Easy solution!

 

[matzetronics]

The old owner said you had to turn it on to activate the car.

there was an aftermarked mod

I really cannot understand why people are doing those stupid modification A) without explaining or labeling them clearly and B) for no obvious reason.

I was lucky in obtaining my old El-Jet 4 without any mod except a different charger and haven't changed anything except a USB Plug as my car doesn't came with a cigarette lighter. OK, i now have LFP Batteries but this didn't require any changes to the original setup.

Gas spring trunk replace

Those Hyundai Gas Springs mentioned on my website do fit well after a small modification and do a good job in keeping the trunk open. All you need to do is to remove a little from the upper bearing with a saw.

 

[Stefanhg]

Continue on +12V testing
So after getting that relay removed I could finally start testing. Sadly the power supply reached current limiter so I had to gamble on it all being okay.
I charged the +12V battery and turned the key - BAM light was on.
All lights did work except for blinkers in the front and high beam headlights constant on, blink of high beam did work.
I have been helping repairing electrics in a previous car with similar switch for light, so I assumed it was broken, until I realized the light switch on dash board did actually do something. After turning it on all worked including light on the trunk window.

Radio also worked, it did cut off when playing loud but I assume the battery was rather discharged.
Wipers did not work, more on that later. Motor itself worked just fine.

Then I was very worried since the car display didn't work. While testing and talking to matzetronics in another thread i learned the +72V was needed to turn it on. I applied a +12V to JP2-12 i could kick start it.



This resulted in my display being alive!



Awesome! Then almost all +12V is tested and being functional!

 

[Stefanhg]

I really cannot understand why people are doing those stupid modifications A) without explaining or labeling them clearly and B) for no obvious reason.

I SO completely agree with this. I hate that too, all things I found weird on this car I have labeled so I know in the future.
Even went as far as to consider buying the heat shrink that works for label writers!.

I was lucky in obtaining my old El-Jet 4 without any mod except a different charger

I assume that is so rare with these. I think there is a charm with them being original, but then again the simplified electricals also just screams "Mod me please!!"

 

[Stefanhg]

Those Hyundai Gas Springs mentioned on my website

I actually haven't looked much into this yet. But thank you for mentioning an alternative was found already! Need to order those soon

 

[matzetronics]

Yeah, very cool, everything 12V should be working once you have the 12V battery connected. This was a good idea by Kewet, as even when the main batteries are exhausted you still have the option of the warning lights, and a strong power source for lights and radio with the separate battery.
As you noticed though, the carcontroller is not powered by this battery but by the DC/DC converter in the rear electrics box. This DC/DC also charges the 12 battery when needed.

 

[Stefanhg]

Yeah, very cool, everything 12V should be working once you have the 12V battery connected. This was a good idea by Kewet, as even when the main batteries are exhausted you still have the option of the warning lights, and a strong power source for lights and radio with the separate battery.
As you noticed though, the car controller is not powered by this battery but by the DC/DC converter in the rear electrics box. This DC/DC also charges the 12 battery when needed.

I love that design choice. Being able to isolate things and test it like that is so nice.

As you noticed though, the car controller is not powered by this battery but by the DC/DC converter in the rear

Yeah except it seems like my car is wired differently. I'll have to put it on my ToDo list to verify.
At the moment my +12V battery is powered off while running the car, but I think that relates to me powering off my +72V every time on the BMS, causing the 2 day power off circuit to not kick in and the DC/DC being active all the time.

 

[matzetronics]

Yeah except it seems like my car is wired differently.

Once you have it open you could take photos of the electric box in the rear. You should find the Curtis, the main relay and 2 direction relays, two relays for the heating, the DC/DC converter and probably a fan controlled by the DC/DC.
The main fuse and the shunt for current measuring should also reside inside that box.
In my Kewet there is another board with the 'shunt driver' cicuit but with a SepEx Motor you don't need that.

 

[Stefanhg]

Testing wipers
So my wipers did not work as mentioned in another post, it just made a sound like the motor tried to move but coudn't. So I started tearing apart the wiper and realized the whole thing was rusted.
But removing the arm connected to wiper motor at least told me the motor worked just fine, so now it is about disassembly of the wipers.
I needed a hand for this so I called a family member, I didn't access the two bolts at the front but dumb me didn't think twice, there was two bolts on the back. So those two popped out and then the whole assembly could be removed.
Family member took it with him to his shop to repair the wipers, got informed today they are now functional so need to pick them up soon!

Then I had to test the motor for window cleaner spray, It did not move either.. Darn it.
So this was pretty interesting, I took it out and was ready to have to cover the thing to avoid the window cleaner to get everywhere but.. It actually was like a thick mass so it actually the liquid in, I kept the tube connected between the tank and motor and same with that, so I put it away on my cable while tearing the motor apart.
Motor actually just needed a clean so while picking up some more paper the tank of course managed to get the old liquid out and nice now I got window cleaner everywhere but motor and tank worked at least!

It also looks like the motor was replaced once, this cable does not seem original

 

[Stefanhg]

Once you have it open you could take photos of the electric box in the rear. You should find the Curtis, the main relay and 2 direction relays, two relays for the heating, the DC/DC converter and probably a fan controlled by the DC/DC.
The main fuse and the shunt for current measuring should also reside inside that box.
In my Kewet there is another board with the 'shunt driver' cicuit but with a SepEx Motor you don't need that.

Here is a few pictures of the wiring including the DC-DC converter installed.
Note the relay mounted is for the brake lights, I am unsure if that's original. I have added a label on this now to avoid confusion

 

[matzetronics]

Note the relay mounted is for the brake lights, I am unsure if that's original.

At least i know that my car doesn't have a relay for the braking lights - its all switched by the switch on the braking pedal alone. If your car had a trailer clutch that could explain an extra relay, but it doesn't have that.

And of course, sorry for the wrong information - your SepEx controller of course doesn't need extra relays for changing between forward and reverse driving, its all done by the Curtis itself. I still wonder though, where the heating relays are (perhaps in that fancy console you have in the cockpit) and what that potentiometer in the box is for. With the Curtis manual for the controller one could find out its meaning.
Nice DC/DC. Obviously Elbil Norge refrained from taking over the old DC/DCs made by who-knows-who-it-was we have in our older Kewets.

It also looks like the motor was replaced once

Yeah, someone had trouble with the original pump.

 

[Stefanhg]

The big day - New batteries



Oh who doesn't love when new things arrive. In my case 22x Envision 4LH3L7 280Ah batteries. Rated for 280A discharge which i was rather picky about.

On top of that I bought a JK B2A24S30P BMS rated for 300A discharge and later also bought the display.

I wouldn't do much with these batteries until I was certain about wiper motor and all other things inside the fronk/battery trunk but I went with it anyways. They arrived within 3 days of ordering from NKON but sadly the batteries I received was not those specified, they were "ESS 72173207-280ah" but those models does not seem to fit either so I was a bit worried. I am very unsure which cells I actually got but chose to accept they are "ESS 72173207", this comes with a single annoying disadvantage that is they are only rated for 157A discharge which at 72V is 11.3kW. I don't know the resistance of motor coil but it the motor can handle it the discharge is too high.

I talked to their support and was told that it would reduce the cycles from 10K to 7K so I was not worried at all, they will surely outlive the car. Was also told that if I just do continues 15 minutes at 13kW they weren't worried about it at all so I think I am gonna be fine.

You don't really realize it while shopping but these batteries are massive



Planning
My goal is to make a proper solution with a closed enclosure for safety both again is water but also from dirt.

My approach
To do things in two steps, first is a quick solution made out of wood, and second is to figure out a proper solution.
My worry is that because the whole fiber body is one big piece I cannot just take it off and install one big box, so it has to be smaller pieces put together with like a glue and screws which does not work well with "what if i need to dissemble it again" . Initially I just looked at some enclosures for +24V designs that worked with prismatic cells, but I had no luck finding something that would fit + I already bought the BMS.. Of course


One thing to remember here is that there is two depths so either you have to make it even or utilize that "stair" design

In my case I chose to utilize it and It actually ended up fitting extremely well together.


Space-wise there is a decent amount of space for a nice box without it interfering with the oil boiler


So I have made a wood piece that is 720x530mm which is the big piece in the bottom, then I cut an smaller piece that was roughly 720x270mm ( can't remember the correct dimensions) for the lowered part.
Then.. The side panels are actually from an on IKEA shelve, same with the one in the back. THat's part of the bottom of that shelve. I think it was from the IKEA KULLEN.
Sadly the right side part was too big, had to downgrade it to another of the thinner piece from.. ANOTHER iKEA product.



Initial goal was to have the upper part have 4 batteries, then the other side have two rows of 9 cells, leaving plenty of room for BMS wiring but when I got the bus bars that came with the batteries i realised it did not fit.



So my solution for this was to rotate all batteries so i ended up with 4 rows, but that still left me with needing 7 bus bars, but that was relatively easy to solve:


So after all this, It was time to throw things together, and the result was pretty satisfying:


For BMS I took a piece of the cardboard box I got for the batteries, made some holes and mounted it with zip ties.
Between the lowered row and the taller row i used one of the jumper cables that was in the original pack, and then the + and - terminal is to the right side (upper right corner is +). This did actually work out really well and I am pretty satisfied with the result.
I still haven't worked on designing the V2 that is the proper solution, need to scratch my head a bit more but I have also considered doing a lazy one with a plastic bag but I don't know how car inspection thinks about that..

 

[Stefanhg]

At least i know that my car doesn't have a relay for the braking lights

I do think it is mod, I think it is a feature I like a lot.
From what I have noticed, it lights up the brake light when you release the speeder, thus engages regenerative braking. Hate some cars does not indicate when it does that!

your SepEx controller of course doesn't need extra relays for changing between forward and reverse driving, its all done by the Curtis itself

Exactly! I did look at some designs where it had a relay for this, but lucky me does not need that!

I still wonder though, where the heating relays are

Heating relay? My model has oil boiler.
oh I wonder if that's a difference too, mine has a fuse box at passenger seat which does also include a few relays for light switching i noticed. I'll take a better picture tomorrow since I have it opened right now.

and what that potentiometer in the box is for

I think it is throttle limiter, so you can simulate an eco mode and reduce the speed control. What is interesting is that it looks like there is a hole for it so like it is a standard thing but was replaced because it went bad.

Nice DC/DC

Yeah it looks really neat, also a brand which is nice but no luck searching for them, so I'm worried it is a custom made thing.

 

[matzetronics]

oh I wonder if that's a difference too, mine has a fuse box at passenger seat which does also include a few relays for light switching i noticed. I'll take a better picture tomorrow since I have it opened right now.

I think these are the relays for flasher, highbeam/lowbeam lights and such, as in every standard car.

thus engages regenerative braking. Hate some cars does not indicate when it does that!

and my El-Jet 4 never had regenerative breaking.

Heating relay? My model has oil boiler.

Are you sure that is standard? It could be that due to the colder climate in Norway, Elbil Norge made this change. The electric heating in my El-Jet is switchable between 400W and 800W which is enough to defrost the windshield but far from comfortable driving on a frosty winter day.

Those LFP blocks look good and very similar to mine. I have the 314Ah type, but the size seems tp be the same.
I mounted all cells below the seats, as you can see in the 'El-Jet 4 restauration' thread. Looks very good in your Buddy. The range with my 20 cells is about 200km now and you can at least expect the same.

All in all it seems you are having some very busy days with the car

 

[Stefanhg]

I think these are the relays for flasher, highbeam/lowbeam lights and such, as in every standard car.

Here are some pictures.





There are two relays here from what it seems, one I know is for high beam, I don't know about the other.

 

[Stefanhg]

and my El-Jet 4 never had regenerative breaking.

Ah that's unlucky. It is such a nice feature!

Are you sure that is standard?

Very sure about it. The way it is integrated and all is very professional.
Here is another picture i found online where it also had the oil boiler controls in the dash. It sits under the radio.

Bil

Norsk vegmuseum - Photographer Mass Haugen

digitaltmuseum.no

which is enough to defrost the windshield but far from comfortable driving on a frosty winter day.

From my testing it seems pretty efficient at heating, measured 40c coming in but of course not winter yet so cannot confirm how it is in the winter.

Those LFP blocks look good and very similar to mine. I have the 314Ah type

Awesome! I was really curious what my range would be! 200km is great!
I did want to mount them under the seat initially, but a mechanic told me loosing the weight in the front would mean that the wheel adjustments are off because you are now missing the front weight load.

All in all it seems you are having some very busy days with the car

Indeed! I get home every day, throw my bag inside and go out to work on it! It is so relaxing.

 

[Stefanhg]

Troubleshooting engine cutoff

So I am having a blast doing test runs with the car, but I am still facing cutoffs while driving which is really fustrating.
To solve this I assume it all came down to bad contact somewhere. So I took out my thermal camera and multimeter and started measuring. If i measured from battery to before HV contact with reference to after fuse and shunt my voltage dropped down to 68V( initially 72V) and I also did another test from, I then also tested the same but with reference to before fuse and shunt and result was basically the same.
So now I know that my issue is between HV relay and batteries.

I took out my thermal camera and looked around, nothing obvious was to be found but I needed to drive it a bit harder to find it.
I then for fun took the camera to the back to see the motor controller temperature and noticed something getting hot:


Notice the breaking between the thermal image, that is my multimeter cable which you see in the picture.
The cable from relay contactor to battery+ on the motor controller was getting hot, and another cable too.

So i removed the cable and I got surprised.


I could actually take off the cable shoe, so it was not properly crimped at all!



I am lucky enough to own a cable crimp took you use together with your hammer so i expanded the crimp, put it back on and whacked it a few times with my hammer and it got nice and tight again!

So now time to figure out the other thing that got hot. I touched a few of the cables and noticed the motor cable was actually loose. I disconnected it and oh yeah it was also almost falling off! I pushed it back in and I am now looking for a crimp tool to borrow since I do not wanna go and hammer the connector inside my car. Would just risk damaging the frame. One problem solved and another found!