Need ideas for saving friction drive system

[linberl]

Let me preface by saying i am not skilled in engineering or electrics, etc. i can fix my analog bike (bike friday). i purchased a little over 2 years ago a One Motor friction drive (crowdfunded price) and it's worked really well for me to use with both my bikes, swapping as needed from the BF to my cargo/trailer bike. Now, however the battery is starting to really lose range. The battery has a rosenberger connection that magnetically attaches to the motor and/or charger. The cells are 18650. That is all I know about the battery, and most regretfully it seems Covid has taken OneMotor out of business.

A friction drive is perfect for my use, super light and swappable. I really don't want a wheel with a hub because I have to lift and carry the bike up lots of stairs.

Are there any options in terms of using a battery from another supplier (does that even work given how little I know about it)?
Are there any other reasonably priced friction drive systems out there that don't require understanding all the connections and electrical stuff?
I am 72 years old, and this old lady sold her car 2 years ago to start biking everywhere instead. I really want to continue riding instead of driving but I'm in need of options to do that.

Any help would be massively appreciated!!!!

 

[DavidD]

The One Motor website seems to work for me. I'm in the US.

https://onemotor.co/order/battery-packs/


I hope you find a replacement and keep on riding!

 

[amberwolf]

Now, however the battery is starting to really lose range. The battery has a rosenberger connection that magnetically attaches to the motor and/or charger. The cells are 18650. That is all I know about the battery, and most regretfully it seems Covid has taken OneMotor out of business.

It's pretty likely that someone in your general area could help you install that type of connector onto a new battery pack, once it's determined what pack you need to buy to replace what you have. If you dont' find it anywhere else, you can get one at ebikes.ca
as an adapter from the Satiator's XLR output, and just cut it off to use it on the battery instead (wasteful, but at least it's in stock).
https://ebikes.ca/xlr-rosenberg.html
https://ebikes.ca/learn/connectors.html#Rosenberger



A quick look at the link above didn't show what voltage the system is, or the Ah or number of cells in series for the batteries, just the wh of the packs (300wh for extended, and 130wh for the compact). So, some speculation and info below that might be useful to help you find a replacement pack (if the OEM is really not operating right now).

There is a detail on the charger on the indepth page stating it is a 4A 200W max charger, which means 200w / 4A = 50v output, which does not match up with any common pack fully charged voltage. It does match a 12s LiIon pack voltage (full), 12 * 4.2v = 50.4v, but 13s (54v) and 14s (58v) are much more common and easier to find as replacement packs. A 12s pack would usually be called a "43v" pack becuase that's the average voltage it would be at. A second detail pointing to a 12s pack is this picture, showing 50.4v on the charger's LED display:
https://i.shgcdn.com/2890df5a-dd91-46b2-8b9c-abb24d156c09/-/format/auto/-/preview/3000x3000/-/quality/lighter/

If it is a 12s 43v pack, then if you have the compact pack 130wh / 43v is 3Ah, which for an 18650 pack probably means 1p (unless they used very low capacity cells and used 2p of them).

Another part of the page says there is automatic charge rate selection based on which pack is connected, 2A for compact and 4A for extended, so they are probably using some pins in the connector either for communication with charger, or more likely just a resistor across the pins that goes into the current limiting circuitry...this may complicate the process of replacing the battery pack with a generic, and could require opening up the original pack to determine what is actually used to tell the charger this information (or else just use a separate charger for the replacement pack. If they are using the CANBUS communication instead, then re-celling your original pack is probably the only viable option (assuming the motor system talks to the battery; if it doesn't then you can still just use a generic battery).

If it's the 300wh pack, then that's 300wh / 43v = 7Ah, which is probably a 2p pack.

(guess on pack sizes also based on this picture
https://i.shgcdn.com/38da10a0-ce13-4734-8e61-cb1765ab1c55/-/format/auto/-/preview/3000x3000/-/quality/lighter/
and this one
https://cdn7.bigcommerce.com/s-axo3755b4e/product_images/uploaded_images/dimensions-weights-6.jpg )
all images also attached here in case links are broken in the future.

 

[linberl]

The One Motor website seems to work for me. I'm in the US.

https://onemotor.co/order/battery-packs/


I hope you find a replacement and keep on riding!

If you try to order, everything comes up sold. out. I've been emailing them with no response, whereas they used to be pretty good at replying. Obviously I will keep trying to reach them but need to start now on coming up with alternative options.

 

[linberl]

Now, however the battery is starting to really lose range. The battery has a rosenberger connection that magnetically attaches to the motor and/or charger. The cells are 18650. That is all I know about the battery, and most regretfully it seems Covid has taken OneMotor out of business.

If it is a 12s 43v pack, then if you have the compact pack 130wh / 43v is 3Ah, which for an 18650 pack probably means 1p (unless they used very low capacity cells and used 2p of them).

I have the 130Wh. So a 12s43v pack. My charge does indeed show 50.4. How can I know if the communication part will work or whether I need to try to find someone to just replace the cells? Do I have to buy a new generic and just try? Any idea on places that will put in new cells? I tried emailing a couple I found online but they never responded to my email and pictures :-(. That actually would be fine with me to just replace the cells if I could find someone reputable to do that. Thanks for all the explanations!

 

[DavidD]

If you try to order, everything comes up sold. out. I've been emailing them with no response, whereas they used to be pretty good at replying. Obviously I will keep trying to reach them but need to start now on coming up with alternative options.

That's too bad. These little ebike startups are in a pretty volatile market but its still unfortunate when they go under.

 

[amberwolf]

I have the 130Wh. So a 12s43v pack. My charge does indeed show 50.4. How can I know if the communication part will work or whether I need to try to find someone to just replace the cells? Do I have to buy a new generic and just try? Any idea on places that will put in new cells? I tried emailing a couple I found online but they never responded to my email and pictures :-(. That actually would be fine with me to just replace the cells if I could find someone reputable to do that. Thanks for all the explanations!

One quick way to test would be to use a tiny thin piece of paper between all the small contacts on the connector when plugging the battery into the motor system and seeing if it still works.

If it does, the system isn't using anything but battery positive and negative (the two big contacts), and simply wiring up a rosenberger connector on a generic 12s battery would then work too. Then just use the charger that comes with the new battery to charge it with, rather than the original one that came with the system (unless the new battery is safe to charge at 4A, just in case it defaults to that without any small connections).

If it doesn't work, but it does still turn on, and you then remove the paper and it works again, then it is doing something with those pins that you'd need to duplicate for a generic replacement battery.


If it doesn't turn on, then the paper is probably preventing the contacts from making good enough connection to get any power to the bike, and it would require another way of testing the disconnection of all the small connections, leaving just the two big ones. (the simplest is to open the battery and temporarily disconnect the small wires, but if that's being done it's just as easy to see where they go and what they connect to...).


The same can be done with the charger, but the catch with this is you probably can't measure the current coming from the charger, and if it defaults to 4A without the little connections, it could damage a battery that isn't meant for that high a charge rate.

 

[2old]

Have you tried ebikemarketplace in Las Vegas? I haven't used them, but they seem to know what they're doing. Perhaps they can rebuild your battery or resolve your problem in some other way.