UMF Freddy build, custom high power battery, mxus 3k

I've built this bike about a year ago and I'm really happy how it turned out!
I'm posting this mainly as an inpiration for other people, maybe it is useful to someone :wink:
There are a lot of pictures, i hope that's ok.

the bike weighs around 36kg with battery

battery:
21s4p, Sony VTC5A (2600mAh, 35A)
60A standard china bms

I really like this kind of battery setup, it is lightweight and has enough energy to ride around the hills around my town for 2 hours or go 40km at reasonable speed on flat terrain.
Plus it's easily removeable and on a long trip you can just take more packs with you. Plus you can easily charge the battery inside the house.
I also already have 3500mAh cells lying around for a low power, high energy version of this pack.

controller:
Kelly KLS7218S, set to 120A battery current (never had a problem with bms cutting off, or getting hot)
ca. 9 kW peak
I'm quite happy with the controller, runs smooth and super quiet, more than enough power for this setup, never gets hot
but i didn't get regen to work like i would expect it..
and my old infineon controller had a lot more punch at startup. really a LOT, two of my friends crashed while making an unwanted power wheelie. so the lack of startup torque is probably a good thing^^ and I'm also not so afraid anymore while driving :lol:

motor:
MXUS 3k 4t


bike





torque arms



display


battery

Nice build and setup. Looks well thought out. I like the battery tray setup with the buckles. I was using hook and loop straps on a previous setup; the ratcheting buckles would have been much better.

Thanks for the pics

Whats the deal with the ta and tensioner mount?
Aluminum I take it, whats the thickness?

wolf said:

battery:
21s4p, Sony VTC5A (2600mAh, 35A)
60A standard china bms

I really like this kind of battery setup, it is lightweight and has enough energy to ride around the hills around my town for 2 hours or go 40km at reasonable speed on flat terrain.

Click to expand...

Great build Wolf! Thanks for sharing.
I'm setting up the same controller and hoping to get a bigger range compared to the KT 22-42A controller I'm running know. With a 1500w hubmotor and a 14S5P 12.3AH Battery (Samsung 25R) I'm getting max. 25km. Yours 2 ours around the hills or the 40km involves some strong legpower I suppose?

Do you use a switch between your battery and controller?

And I really like your display! Is that hard to setup?

Lots of innovative aspects in your build wolf. :thumb:

Can you show details of the rack mounting? My next build will be a FS and my usage requires a strong carrier rack.

markz said:

Thanks for the pics
Whats the deal with the ta and tensioner mount?
Aluminum I take it, whats the thickness?

Click to expand...

I'm not exactly sure what you mean.
All the parts I've added are 5mm stainless steel, the frame is aluminum. On the left side the inner plate is screwed to the brake mount. On the right side two plates are clamped together with the frame in between.

raggertje said:

Great build Wolf! Thanks for sharing.
I'm setting up the same controller and hoping to get a bigger range compared to the KT 22-42A controller I'm running know. With a 1500w hubmotor and a 14S5P 12.3AH Battery (Samsung 25R) I'm getting max. 25km. Yours 2 ours around the hills or the 40km involves some strong legpower I suppose?
Do you use a switch between your battery and controller?
And I really like your display! Is that hard to setup?

Click to expand...

I should have explained in detail how the 2 hours are meant. The tour I'm referring to is 14km one way and 600m in height, half gravel, half road. I don't pedal at all. 2 hours are the whole round trip with some stops for enjoying the view. I'm going at a comfortable speed, not pushing it to the limits. And I never came close to running out of battery.

I don't have a switch on the main power lines, just the controller turn on switch and an anti spark connector.

Well once it's built it's easy to setup the display, the connections are just like the CA. For configuration, you have to upload the program via usb though. The new version I'm building has wifi and bluetooth and can be configured easily with your phone. But I have a lot of other projects going on and don't know when I will continue.
All of my ebikes have this display, or an older version of it. Mainly because of the "legal mode" :wink:

99t4 said:

Lots of innovative aspects in your build wolf. :thumb:
Can you show details of the rack mounting? My next build will be a FS and my usage requires a strong carrier rack.

Click to expand...

In this build I made a 3d printed piece and clamped it to the frame. And the lower parts are screwed to the torque arms. But the rack I'm using isn't very strong unfortunately.
The other picture is showing the mount on my non ebike. This one is not very sturdy, but it could easily be built stronger.