Acceleration problem

I purchased my first electric motorcycle (Zero S 2013) in August 2020. I tested an FX earlier, but had no real experience with such bikes. However, I enjoyed the bike (it was silent and had decent acceleration) as time passed by I started to feel like, that its acceleration is much less than expected. You can read statements like "It is like 1000cc ICE" and such, and later you find a 250 KTM Duke to be faster than your bike. Something must be wrong.

I made a test run, and the bike reached 100kph in ~20 secs. Wow, that's not, what it should be. I looked around the Zeromanual webpage and found a decent description about the throttle. That's not rocket science, a simple potentiometer. So I dismantled it. At the connector I found some green stuff (water???) but not that bad. I tried to measure, but the potentiometer was not showing any "values". The measurement device was jumping around 0-1.2k, but not in a way, as you would expect from a potentiometer. I was really sad, that I am getting too old, and being unable to understand, how such a simple thing works. So I decided to put everything back, and bring the bike to the repair shop.

But the bike had other plans. I reattached the throttle, but no reaction. Nothing. So what next? Let's use a 5k potentiometer and try to test it.

Connecting the 3 wires based on the Zeromanual description was not that complicated, and suddenly the bike was willing to move. OK, so it was obvious, that I will need a new throttle. But knowing, that the old potentiometer was somewhat dead, I wanted to test how the bike works now. I could not wait, until the replacement item arrives.

So I decided to 3D print a new counterpart for the throttle (matching the temporary potentiometer) and a gear.

After some iterations I managed to create a working solution, and I was ready to test the new system. The only thing I did not manage to reattach was the spring. You need to mount the throttle with the spring in a way, that the "closed" position is ~0 Ohm. This was simply not possible for me. Still, I managed to mount everything without the spring, and the bike was running. The experience was amazing, Acceleration, like never seen before - at least not from this bike :)

Of course, 2 days later the replacement arrived, and I could fix the bike. I bought some water resistant connector, and replaced the original one, which was old and slightly damaged. Since that the throttle is working fine :)

The throttle: https://www.amazon.de/-/en/gp/product/B07CJJVSLL/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

The connector set: https://www.amazon.de/-/en/gp/product/B07RXZN7SX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

DC-DC converter

The bike was standing in the rain for a weekend. Actually it was only raining for 1 day, but that's not important. As I wanted to ride, I realized, that the lights are on. And I could not switch it off.

As usual, I started with the Zeromanual (https://zeromanual.com/wiki/DC-DC_12V_Converter). Here I found a lot of interesting information about the DCDC converter. Following further chats on Facebook and a lot of measurement and checking and reading, I realized, that the DCDC converter has a typical error: The enable signal cable is dead, and the DCDC gives 12V all the time. This is not good, because this means, that you cannot switch off the lights, and other 12V systems. It might also not be healthy for the DCDC to be turned on 7/24. The replacement costs n x 100USD and actually the old one is still working!

The first step was to remove the fuses (2 of them, one for the headlights and one for the tacho, the other two controls the indicators and the horn, it is OK) everytime I stop the bike. This was not very comfortable, nor safe.

The next step was to install a simple switch. I cut the ~100 input to the DCDC and with an additional headlight switch, I had to switch on the 12V system every time I started the bike. This is OK, as a workaround, but not very elegant on the long term.

The final plan was to insert a relay, which would switch off the 100V Input and thus shut down the 12V. The enable signal of the bike would be used as trigger for the relay. First I tried to use a 220V relay, but the enable signal was not able to pull the switch. "Luckily" this problem is well known in the community, and based on a Youtube video (https://www.youtube.com/watch?v=0iFOMUXae1g&feature=youtu.be&fbclid=IwAR3s4ZXQSW1grKmXDVvnnZwszjRVMKUGof4cBH1jUdi_AD0J2RVILsFPI5g) I could order the proper relay. The video itself is in spanish (?) thus not so easy to understand for me, but with autocaption it is OK. So the final solution looks like following the picture below.

Relay: Phoenix Contact model REL-PR1-110DC/1/MB - 2908044 (I guess any other 100V DC relay would be OK, but I used this one as well...)