Zero XU & DS

A friend left these bikes at my place:





Both are new, but probably a little test driven. Now with dead batteries.

I have opened them up, the ds with dc motor has a big 14s battery:



The XU has a 18s battery:



At the moment I am trying to decide what to do..
The XU seems to have a sevcon controller, I think they are 48 or 80v.
My guess is 80v then, so it should be no problem running 24s if I could reprogram it.



Like this, but it would be pretty crowded in the box.

But if I build a 18s, I should be able to run the standard bms and everything should work right?



There is a connector that you would normally reach trough a hole in the case, is that needed?
There are also some leds that you can see trough a glass in the case, what are those for?
The interior of the battery would be a bit different on mine so the bms wouldnt fit were it normally were mounted

I decided to build a 18s battery for the xu, and try to get it to work with the bms.
I cant use the connection pcb, so I am reverse engineering that to find what pins everything goes to.





I am not sure if I have found pins for RT1 and RT2 though. I thought they were some kind of resistor (Resistor Temperature?)
I expected to get a ohm reading when I found the right pins, but it dosent seem to happen.
There are other temp sensors, so I dont know what what use they would be.
Any ideas?

In the picture, one of the connections on RT2 looks like it didn't solder properly. It may be just an optical illusion. You could measure it right on the board to test.

It must be an illusion, but it is to small to see anything without magnification.
However, I eventually found the right pins. They are 10Kohm ntc resistors.
They must be there to measure the pcb during balancing.

I havent been updating very much here, but here are a few pictures from the process:



I placed the current sensor on the positive pole on the battery.







As I used one 12s module and a half module I got a decent amount of space in front of the half.
But very tight in the front and back of the whole module.

The batteries were pretty well built except for one thing.
They are not even close to watertight.
I have heard the saying "it never rains in southern California", but come on:





And the sides is on top of the top plate, so water flowing on the top will get in..
In a way it is a god thing that there are gaps in the bottom, so the water can get out again
What if the owner thinks it is a good idea to wash the bike with a hose or pressure washer?

I forgot this picture:



Note the mileage, 7,2km

Dosent seem to be much interest in these bikes?
Well, I havent had it on top of my priorities either. But I made a go for it, and tried to get the ds done too now.

It would be easy to make a 24s2p battery, then I could just stack the modules 2 in the bottom and 2 on top of them and bolt them all together.
But then I probably have to change most of the electrical system, so I decided to go for 14s3p anyway.
I will use 3 of the 12s1p modules and parallel them, and build a 2s3p module.



I cut up a module and made 3 of these 2s blocks.

I 3d printed these separation blocks:



But these are pla, that seems not to be very suitable so I later made new ones in abs.
It will look something like this:


I had to move the top 2 modules forward, to have room for the bms (that seems to be cast on the back plate of the battery housing)
and make room for the wiring.

I made some busbars:



I think they turned out really well, I wouldent have thought they came from copper pipe if I didnt know they did..



Made some fasteners, so I can mount the modules in both the top and bottom of the box:



How it looks when mounted together:







Getting the big lump in there was no joke..





It took some more work from there to the final position



Finally its alive
This one had some more mileage, 137km

An interesting thread for the zero dc bikes:
This bike has decent power when it is up to speed, but not much at low speed. I suppose I cant do much about that, but the throttle response is terrible. Like you can just hit full throttle and back off 30sec later if it turned out to be too much..
Maybe I can do something about that.

This is a very clean looking build!

Thanks

I tried to program the alltrax axe dc controller in the DS today, but I cant get the program to connect to the controller.
I couldent find a usb to db9 adapter, or a db9 wire at home.
But I did find a CP2104 usb to rx/tx adapter that I connected to pin 2 & 3 on a db9 connector, and also ground to pin 5.
The computer connects to the adapter:



It seems to think it is a mouse, but it has worked to connect to a fardriver before.



There dosent seem to be possible to choose com port on the program.

The program is supposed to be for 2006 and newer controllers, maybe a bit odd with copyright 2002-2008?
Anyone with experience programming these?
Maybe I should just get a rs232 adapters, and it will just work?

Eventually I was able to connect.
There was several problems I think, one was that when the bike is on the sidestand the controller is off..
I did buy a usb to serial cable, not sure if it was necessary.
I also installed the program on three computers, one windows XP, one with 7 and one with 10. It was the one with 10 that ended up working.
At this time I concluded that there wasnt much I could do, it was pretty much maxed out

Then I got a problem, the bike wouldnt run any more. I saw that the red triangle symbol was blinking some sort of code.
I was able to find a manual online with instructions to decipher the code, so I didnt have to just guess or make a new electrical system
It turned out to mean "throttle high" or something like that. I got about 140ohm with released throttle, and I tried a 100ohm resistor instead of the throttle. Then it would turn on, so I suppose the throttle should go lower.

Got hold of another throttle, that had more like 10ohm released.
Tried to fix mine:





It seems like I cant take the pot apart further than this.
Does anyone know if these potentiometers can be bought somewhere, or repaired somehow?
The bike has done like 20km, so it is a bit strange if the throttle is worn out

Anyway, I realized that the throttle goes to the central computer and is forwarded from there to the controller.
I made a perfect test set up and went out testing:





Ahum, it was a little difficult driving without a seat, and trying to hold on to the meter and wiring..
But I for sure could see that there was some serious throttle taming going on.

I changed the wiring and wired the throttle directly to the controller, what a difference
I got throttle response, I can make burnouts (on gravel or clinker)
Anyway, after I had mounted everything together again I noticed that there is another problem now, it is terrible to drive at part throttle. Maybe I should try to lower the throttle response a little, and see if it helps. But then I have to take off the skid plate again

j bjork said:

Maybe I should try to lower the throttle response a little, and see if it helps. But then I have to take off the skid plate again

Click to expand...

Maybe you can cobble something together and leave a programming wire hanging out so you don't have to go through all that hassle every time you want to change some setting.

eee291 said:

Maybe you can cobble something together and leave a programming wire hanging out so you don't have to go through all that hassle every time you want to change some setting.

Click to expand...

It is pretty tight between the skid plate and controller, and the connector for programming is facing down.





I kind of thought it didnt matter, once set up I probably wont touch it any more.
I tried lowering throttle up rate, and down rate too:



It didnt have very much effect, it was still rather touchy from stationary but a little sluggish when moving.
But it was still just as jerky when trying to run at part throttle.



I have these settings to play with as well, but changing the throttle curve didnt help much either.
I tried 0-5v throttle, but it wouldent run at all. It is possible that I had to turn on and off the controller for that to work, and maybe I didnt.
I wonder if it might be the throttle after all, Im thinking I should have noticed on the first testride if it was like this, but I probably tested mostly full throttle

I have another problem with the bike now, the bms beeps 3 times in maybe 20-30min intervals when the bike just stands there turned off.
I can drive it and charge it without problems. I tried charging it full if there was some automatic alarm when it hasnt been charged for a long time or something, but no difference.

I find 2 or 4 beeps in the manual, but that is with key on. I don't find anything for 3 beeps, or any beeps with key off
Anyone with insight?

Your use of the OG battery for the new one to climb up on is awesome...

Question about the old cylinder cell pack... Was there any structural components supporting the top group? I've yellow-annotated one of your photos for the area in question...

Also - phenomenal retrofit of an entirely different battery design into the same OG shell. Great innovation at work.

Yes, there is an alu shelf or what to call it that it rests on.
https://endless-sphere.com/sphere/proxy.php?image=https%3A%2F%2Fi.imgur.com%2F2RHZc4w.jpg&hash=0fd2367f47428930c51abac3a5aefd01

It is the dark grey to the right in the picture. Under it are contactor and fuses etc. that is on the outside of the battery.
It should be the other way around in the picture you quoted, the top part sticking out should face the rear of the bike.